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Bens N, Kulkarni P, Ferris CF. Changes in cerebral vascular reactivity following mild repetitive head injury in awake rats: modeling the human experience. Exp Brain Res 2024; 242:2433-2442. [PMID: 39162729 PMCID: PMC11422282 DOI: 10.1007/s00221-024-06907-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 08/01/2024] [Indexed: 08/21/2024]
Abstract
The changes in brain function in response to mild head injury are usually subtle and go undetected. Physiological biomarkers would aid in the early diagnosis of mild head injury. In this study we used hypercapnia to follow changes in cerebral vascular reactivity after repetitive mild head injury. We hypothesized head injury would reduce vascular reactivity. Rats were maintained on a reverse light-dark cycle and head impacted daily at 24 h intervals over three days. All head impacts were delivered while rats were fully awake under red light illumination. There was no neuroradiological evidence of brain damage. After the 3rd impact rats were exposed to 5% CO2 and imaged for changes in BOLD signal. All imaging was done while rats were awake without the confound of anesthesia. The data were registered to a 3D MRI rat atlas with 171 segmented brain areas providing site specific information on vascular reactivity. The changes in vascular reactivity were not uniform across the brain. The prefrontal cortex, somatosensory cortex and basal ganglia showed the hypothesized decrease in vascular reactivity while the cerebellum, thalamus, brainstem, and olfactory system showed an increase in BOLD signal to hypercapnia.
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Affiliation(s)
- Nicole Bens
- Center for Translational Neuroimaging, Northeastern University, 360 Huntington Ave, Boston, MA, 02115, USA
| | - Praveen Kulkarni
- Center for Translational Neuroimaging, Northeastern University, 360 Huntington Ave, Boston, MA, 02115, USA
| | - Craig F Ferris
- Center for Translational Neuroimaging, Northeastern University, 360 Huntington Ave, Boston, MA, 02115, USA.
- Departments of Psychology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA.
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2
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Chen F, Zhao J, Meng F, He F, Ni J, Fu Y. The vascular contribution of apolipoprotein E to Alzheimer's disease. Brain 2024; 147:2946-2965. [PMID: 38748848 DOI: 10.1093/brain/awae156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 03/23/2024] [Accepted: 04/21/2024] [Indexed: 09/04/2024] Open
Abstract
Alzheimer's disease, the most prevalent form of dementia, imposes a substantial societal burden. The persistent inadequacy of disease-modifying drugs targeting amyloid plaques and neurofibrillary tangles suggests the contribution of alternative pathogenic mechanisms. A frequently overlooked aspect is cerebrovascular dysfunction, which may manifest early in the progression of Alzheimer's disease pathology. Mounting evidence underscores the pivotal role of the apolipoprotein E gene, particularly the apolipoprotein ε4 allele as the strongest genetic risk factor for late-onset Alzheimer's disease, in the cerebrovascular pathology associated with Alzheimer's disease. In this review, we examine the evidence elucidating the cerebrovascular impact of both central and peripheral apolipoprotein E on the pathogenesis of Alzheimer's disease. We present a novel three-hit hypothesis, outlining potential mechanisms that shed light on the intricate relationship among different pathogenic events. Finally, we discuss prospective therapeutics targeting the cerebrovascular pathology associated with apolipoprotein E and explore their implications for future research endeavours.
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Affiliation(s)
- Feng Chen
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Jing Zhao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou 215123, China
| | - Fanxia Meng
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Fangping He
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Jie Ni
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Yuan Fu
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
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3
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DeConne TM, Fancher IS, Edwards DG, Trott DW, Martens CR. CD8 + T-cell metabolism is related to cerebrovascular reactivity in middle-aged adults. Am J Physiol Regul Integr Comp Physiol 2024; 326:R416-R426. [PMID: 38406845 DOI: 10.1152/ajpregu.00267.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/13/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
Cerebrovascular reactivity (CVR) decreases with advancing age, contributing to increased risk of cognitive impairment; however, the mechanisms underlying the age-related decrease in CVR are incompletely understood. Age-related changes to T cells, such as impaired mitochondrial respiration, increased inflammation, likely contribute to peripheral and cerebrovascular dysfunction in animals. However, whether T-cell mitochondrial respiration is related to cerebrovascular function in humans is not known. Therefore, we hypothesized that peripheral T-cell mitochondrial respiration would be positively associated with CVR and that T-cell glycolytic metabolism would be negatively associated with CVR. Twenty middle-aged adults (58 ± 5 yr) were recruited for this study. T cells were separated from peripheral blood mononuclear cells. Cellular oxygen consumption rate (OCR) and extracellular acidification rate (ECAR, a marker of glycolytic activity) were measured using extracellular flux analysis. CVR was quantified using the breath-hold index (BHI), which reflects the change in blood velocity in the middle-cerebral artery (MCAv) during a 30-s breath-hold. In contrast to our hypothesis, we found that basal OCR in CD8+ T cells (β = -0.59, R2 = 0.27, P = 0.019) was negatively associated with BHI. However, in accordance with our hypothesis, we found that basal ECAR (β = -2.20, R2 = 0.29, P = 0.015) and maximum ECAR (β = -50, R2 = 0.24, P = 0.029) were negatively associated with BHI in CD8+ T cells. There were no associations observed in CD4+ T cells. These associations appeared to be primarily mediated by an association with the pressor response to the breath-hold test. Overall, our findings suggest that CD8+ T-cell respiration and glycolytic activity may influence CVR in humans.NEW & NOTEWORTHY Peripheral T-cell metabolism is related to in vivo cerebrovascular reactivity in humans. Higher glycolytic metabolism in CD8+ T cells was associated with lower cerebrovascular reactivity to a breath-hold in middle-aged adults, which is possibly reflective of a more proinflammatory state in midlife.
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Affiliation(s)
- Theodore M DeConne
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States
| | - Ibra S Fancher
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
| | - Daniel W Trott
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
| | - Christopher R Martens
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
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4
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van der Horn HJ, Vakhtin AA, Julio K, Nitschke S, Shaff N, Dodd AB, Erhardt E, Phillips JP, Pirio Richardson S, Deligtisch A, Stewart M, Suarez Cedeno G, Meles SK, Mayer AR, Ryman SG. Parkinson's disease cerebrovascular reactivity pattern: A feasibility study. J Cereb Blood Flow Metab 2024:271678X241241895. [PMID: 38578669 DOI: 10.1177/0271678x241241895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
A mounting body of research points to cerebrovascular dysfunction as a fundamental element in the pathophysiology of Parkinson's disease (PD). In the current feasibility study, blood-oxygen-level-dependent (BOLD) MRI was used to measure cerebrovascular reactivity (CVR) in response to hypercapnia in 26 PD patients and 16 healthy controls (HC), and aimed to find a multivariate pattern specific to PD. Whole-brain maps of CVR amplitude (i.e., magnitude of response to CO2) and latency (i.e., time to reach maximum amplitude) were computed, which were further analyzed using scaled sub-profile model principal component analysis (SSM-PCA) with leave-one-out cross-validation. A meaningful pattern based on CVR latency was identified, which was named the PD CVR pattern (PD-CVRP). This pattern was characterized by relatively increased latency in basal ganglia, sensorimotor cortex, supplementary motor area, thalamus and visual cortex, as well as decreased latency in the cerebral white matter, relative to HC. There were no significant associations with clinical measures, though sample size may have limited our ability to detect significant associations. In summary, the PD-CVRP highlights the importance of cerebrovascular dysfunction in PD, and may be a potential biomarker for future clinical research and practice.
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Affiliation(s)
- Harm Jan van der Horn
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
| | - Andrei A Vakhtin
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
| | - Kayla Julio
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
| | - Stephanie Nitschke
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
| | - Nicholas Shaff
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
| | - Andrew B Dodd
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
| | - Erik Erhardt
- Department of Mathematics and Statistics, University of New Mexico, Albuquerque, NM, USA
| | - John P Phillips
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
| | - Sarah Pirio Richardson
- Nene and Jamie Koch Comprehensive Movement Disorder Center, Department of Neurology, University of New Mexico, Albuquerque, NM, USA
- New Mexico VA Health Care System, Albuquerque, NM, USA
| | - Amanda Deligtisch
- Nene and Jamie Koch Comprehensive Movement Disorder Center, Department of Neurology, University of New Mexico, Albuquerque, NM, USA
| | - Melanie Stewart
- Nene and Jamie Koch Comprehensive Movement Disorder Center, Department of Neurology, University of New Mexico, Albuquerque, NM, USA
| | - Gerson Suarez Cedeno
- Nene and Jamie Koch Comprehensive Movement Disorder Center, Department of Neurology, University of New Mexico, Albuquerque, NM, USA
| | - Sanne K Meles
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Andrew R Mayer
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
| | - Sephira G Ryman
- Department of Translational Neuroscience, The Mind Research Network, Albuquerque, NM, USA
- Nene and Jamie Koch Comprehensive Movement Disorder Center, Department of Neurology, University of New Mexico, Albuquerque, NM, USA
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Daher A, Payne S. The conducted vascular response as a mediator of hypercapnic cerebrovascular reactivity: A modelling study. Comput Biol Med 2024; 170:107985. [PMID: 38245966 DOI: 10.1016/j.compbiomed.2024.107985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/29/2023] [Accepted: 01/13/2024] [Indexed: 01/23/2024]
Abstract
It is well established that the cerebral blood flow (CBF) shows exquisite sensitivity to changes in the arterial blood partial pressure of CO2 ( [Formula: see text] ), which is reflected by an index termed cerebrovascular reactivity. In response to elevations in [Formula: see text] (hypercapnia), the vessels of the cerebral microvasculature dilate, thereby decreasing the vascular resistance and increasing CBF. Due to the challenges of access, scale and complexity encountered when studying the microvasculature, however, the mechanisms behind cerebrovascular reactivity are not fully understood. Experiments have previously established that the cholinergic release of the Acetylcholine (ACh) neurotransmitter in the cortex is a prerequisite for the hypercapnic response. It is also known that ACh functions as an endothelial-dependent agonist, in which the local administration of ACh elicits local hyperpolarization in the vascular wall; this hyperpolarization signal is then propagated upstream the vascular network through the endothelial layer and is coupled to a vasodilatory response in the vascular smooth muscle (VSM) layer in what is known as the conducted vascular response (CVR). Finally, experimental data indicate that the hypercapnic response is more strongly correlated with the CO2 levels in the tissue than in the arterioles. Accordingly, we hypothesize that the CVR, evoked by increases in local tissue CO2 levels and a subsequent local release of ACh, is responsible for the CBF increase observed in response to elevations in [Formula: see text] . By constructing physiologically grounded dynamic models of CBF and control in the cerebral vasculature, ones that integrate the available knowledge and experimental data, we build a new model of the series of signalling events and pathways underpinning the hypercapnic response, and use the model to provide compelling evidence that corroborates the aforementioned hypothesis. If the CVR indeed acts as a mediator of the hypercapnic response, the proposed mechanism would provide an important addition to our understanding of the repertoire of metabolic feedback mechanisms possessed by the brain and would motivate further in-vivo investigation. We also model the interaction of the hypercapnic response with dynamic cerebral autoregulation (dCA), the collection of mechanisms that the brain possesses to maintain near constant CBF despite perturbations in pressure, and show how the dCA mechanisms, which otherwise tend to be overlooked when analysing experimental results of cerebrovascular reactivity, could play a significant role in shaping the CBF response to elevations in [Formula: see text] . Such in-silico models can be used in tandem with in-vivo experiments to expand our understanding of cerebrovascular diseases, which continue to be among the leading causes of morbidity and mortality in humans.
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Affiliation(s)
- Ali Daher
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom.
| | - Stephen Payne
- Institute of Applied Mechanics, National Taiwan University, Taiwan
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Shirzad M, Van Riesen J, Behboodpour N, Heath M. 10-min exposure to a 2.5% hypercapnic environment increases cerebral blood blow but does not impact executive function. LIFE SCIENCES IN SPACE RESEARCH 2024; 40:143-150. [PMID: 38245339 DOI: 10.1016/j.lssr.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 01/22/2024]
Abstract
Space travel and exploration are associated with increased ambient CO2 (i.e., a hypercapnic environment). Some work reported that the physiological changes (e.g., increased cerebral blood flow [CBF]) associated with a chronic hypercapnic environment contributes to a "space fog" that adversely impacts cognition and psychomotor performance, whereas other work reported no change or a positive change. Here, we employed the antisaccade task to evaluate whether transient exposure to a hypercapnic environment influences top-down executive function (EF). Antisaccades require a goal-directed eye movement mirror-symmetrical to a target and are an ideal tool for identifying subtle EF changes. Healthy young adults (aged 19-25 years) performed blocks of antisaccade trials prior to (i.e., pre-intervention), during (i.e., concurrent) and after (i.e., post-intervention) 10-min of breathing factional inspired CO2 (FiCO2) of 2.5% (i.e., hypercapnic condition) and during a normocapnic (i.e., control) condition. In both conditions, CBF, ventilatory and cardiorespiratory responses were measured. Results showed that the hypercapnic condition increased CBF, ventilation and end-tidal CO2 and thus demonstrated an expected physiological adaptation to increased FiCO2. Notably, however, null hypothesis and equivalence tests indicated that concurrent and post-intervention antisaccade reaction times were refractory to the hypercapnic environment; that is, transient exposure to a FiCO2 of 2.5% did not produce a real-time or lingering influence on an oculomotor-based measure of EF. Accordingly, results provide a framework that - in part - establishes the FiCO2 percentage and timeline by which high-level EF can be maintained. Future work will explore CBF and EF dynamics during chronic hypercapnic exposure as more direct proxy for the challenges of space flight and exploration.
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Affiliation(s)
- Mustafa Shirzad
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, 1151 Richmond St, London, ON N6A 3K7, Canada
| | - James Van Riesen
- Canadian Centre for Activity and Aging, University of Western Ontario, 1201 Western Rd, London, ON N6G 1H1, Canada
| | - Nikan Behboodpour
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, 1151 Richmond St, London, ON N6A 3K7, Canada
| | - Matthew Heath
- School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, 1151 Richmond St, London, ON N6A 3K7, Canada; Canadian Centre for Activity and Aging, University of Western Ontario, 1201 Western Rd, London, ON N6G 1H1, Canada; Graduate Program in Neuroscience, University of Western Ontario, 1151 Richmond St, London, ON N6A 3K7, Canada.
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7
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Wang J, Li H, Jia J, Shao X, Li Y, Zhou Y, Wang H, Jin L. Progressive Cerebrovascular Reactivity Reduction Occurs in Parkinson's Disease: A Longitudinal Study. Mov Disord 2024; 39:94-104. [PMID: 38013597 DOI: 10.1002/mds.29671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/15/2023] [Accepted: 11/07/2023] [Indexed: 11/29/2023] Open
Abstract
BACKGROUND The change of microvascular function over the course of Parkinson's disease (PD) remains unclear. OBJECTIVE We aimed to ascertain regional cerebrovascular reactivity (CVR) changes in the patients with PD at baseline (V0) and during a 2-year follow-up period (V1). We further investigated whether alterations in CVR were linked to cognitive decline and brain functional connectivity (FC). METHODS We recruited 90 PD patients and 51 matched healthy controls (HCs). PD patients underwent clinical evaluations, neuropsychological assessments, and magnetic resonance (MR) scanning at V0 and V1, whereas HCs completed neuropsychological assessments and MR at baseline. The analysis included evaluating CVR and FC maps derived from resting-state functional magnetic resonance imaging and investigating CVR measurement reproducibility. RESULTS Compared with HCs, CVR reduction in left inferior occipital gyrus and right superior temporal cortex at V0 persisted at V1, with larger clusters. Longitudinal reduction in CVR of the left posterior cingulate cortex correlated with decline in Trail Making Test B performance within PD patients. Reproducibility validation further confirmed these findings. In addition, the results also showed that there was a tendency for FC to be weakened from posterior to anterior with the progression of the disease. CONCLUSIONS Microvascular dysfunction might be involved in disease progression, subsequently weaken brain FC, and partly contribute to executive function deficits in early PD. © 2023 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Jian Wang
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
- Department of Radiology, Zhongshan Hospital, Fudan University (Xiamen Branch), China
| | - Hongwei Li
- Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, China
| | - Jia Jia
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China
- Department of Neurology, Shanghai Xuhui Central Hospital, Shanghai, China
| | - Xiali Shao
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuanfang Li
- Department of Neurology, Zhongshan Hospital, Fudan University (Xiamen Branch), Xiamen, China
| | - Ying Zhou
- Department of Neurology, Zhongshan Hospital, Fudan University (Xiamen Branch), Xiamen, China
| | - He Wang
- Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, China
- Human Phenome Institute, Fudan University, Shanghai, China
- Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence (Fudan University), Ministry of Education, Shanghai, China
| | - Lirong Jin
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China
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Jeong H, Pan Y, Akhter F, Volkow ND, Zhu D, Du C. Impairment of cerebral vascular reactivity and resting blood flow in early-staged transgenic AD mice: in vivo optical imaging studies. RESEARCH SQUARE 2023:rs.3.rs-3579916. [PMID: 37987006 PMCID: PMC10659553 DOI: 10.21203/rs.3.rs-3579916/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Background Alzheimer's disease (AD) is a neurodegenerative disorder with progressive cognitive decline in aging individuals that poses a significant challenge to patients due to an incomplete understanding of its etiology and lack of effective interventions. While "the Amyloid Cascade Hypothesis," the abnormal accumulation of amyloid-β in the brain, has been the most prevalent theory for AD, mounting evidence from clinical and epidemiological studies suggest that defects in cerebral vessels and hypoperfusion appear prior to other pathological manifestations and might contribute to AD, leading to "the Vascular Hypothesis." However, assessment of structural and functional integrity of the cerebral vasculature in vivo in the brain from AD rodent models has been challenging owing to the limited spatiotemporal resolution of conventional imaging technologies. Methods We employed two in vivo imaging technologies, i.e., Dual-Wavelength Imaging (DWI) and Optical Coherence Tomography (OCT), to evaluate cerebrovascular reactivity (CVR; responsiveness of blood vessels to vasoconstriction as triggered by cocaine) in a relatively large field of view of the cortex in vivo, and 3D quantitative cerebrovascular blood flow (CBF) imaging in living transgenic AD mice at single vessel resolution. Results Our results showed significantly impaired CVR and reduced CBF in basal state in transgenic AD mice compared to non-transgenic littermates in an early stage of AD progression. Changes in total hemoglobin (Δ[HbT]) in response to vasoconstriction were significantly attenuated in AD mice, especially in arteries and tissue, and the recovery time of Δ[HbT] after vasoconstriction was shorter for AD than WT in all types of vessels and cortical tissue, thereby indicating hypoperfusion and reduced vascular flexibility. Additionally, our 3D OCT images revealed that CBF velocities in arteries were slower and that the microvascular network was severely disrupted in the brain of AD mice. Conclusions These results suggest significant vascular impairment in basal CBF and dynamic CVR in the neurovascular network in a rodent model of AD at an early stage of the disease. These cutting-edge in vivo optical imaging tools offer an innovative venue for detecting early neurovascular dysfunction in relation to AD pathology and pave the way for clinical translation of early diagnosis and elucidation of AD pathogenesis in the future.
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Affiliation(s)
- Hyomin Jeong
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Firoz Akhter
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Nora D. Volkow
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20857, USA
| | - Donghui Zhu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
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Vestergaard MB, Laursen JC, Heinrich NS, Rossing P, Hansen TW, Larsson HBW. Patients with type 1 diabetes and albuminuria have a reduced brain glycolytic capability that is correlated with brain atrophy. Front Neurosci 2023; 17:1229509. [PMID: 37869511 PMCID: PMC10585154 DOI: 10.3389/fnins.2023.1229509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 09/14/2023] [Indexed: 10/24/2023] Open
Abstract
Introduction Patients with type 1 diabetes (T1D) demonstrate brain alterations, including white matter lesions and cerebral atrophy. In this case-control study, we investigated if a reason for this atrophy could be because of diabetes-related complications affecting cerebrovascular or cerebral glycolytic functions. Cerebral physiological dysfunction can lead to energy deficiencies and, consequently, neurodegeneration. Methods We examined 33 patients with T1D [18 females, mean age: 50.8 years (range: 26-72)] and 19 matched healthy controls [7 females, mean age: 45.0 years (range: 24-64)]. Eleven (33%) of the patients had albuminuria. Total brain volume, brain parenchymal fraction, gray matter volume and white matter volume were measured by anatomical MRI. Cerebral vascular and glycolytic functions were investigated by measuring global cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2) and cerebral lactate concentration in response to the inhalation of hypoxic air (12-14% fractional oxygen) using phase-contrast MRI and magnetic resonance spectroscopy (MRS) techniques. The inspiration of hypoxic air challenges both cerebrovascular and cerebral glycolytic physiology, and an impaired response will reveal a physiologic dysfunction. Results Patients with T1D and albuminuria had lower total brain volume, brain parenchymal fraction, and gray matter volume than healthy controls and patients without albuminuria. The inhalation of hypoxic air increased CBF and lactate in all groups. Patients with albuminuria had a significantly (p = 0.032) lower lactate response compared to healthy controls. The CBF response was lower in patients with albuminuria compared to healthy controls, however not significantly (p = 0.24) different. CMRO2 was unaffected by the hypoxic challenge in all groups (p > 0.16). A low lactate response was associated with brain atrophy, characterized by reduced total brain volume (p = 0.003) and reduced gray matter volume (p = 0.013). Discussion We observed a reduced response of the lactate concentration as an indication of impaired glycolytic activity, which correlated with brain atrophy. Inadequacies in upregulating cerebral glycolytic activity, perhaps from reduced glucose transporters in the brain or hypoxia-inducible factor 1 pathway dysfunction, could be a complication in diabetes contributing to the development of neurodegeneration and declining brain health.
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Affiliation(s)
- Mark B. Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital – Rigshospitalet, Glostrup, Denmark
| | | | | | - Peter Rossing
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | | | - Henrik B. W. Larsson
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital – Rigshospitalet, Glostrup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
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10
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Dasari Y, Duffin J, Sayin ES, Levine HT, Poublanc J, Para AE, Mikulis DJ, Fisher JA, Sobczyk O, Khamesee MB. Convolutional Neural Networks to Assess Steno-Occlusive Disease Using Cerebrovascular Reactivity. Healthcare (Basel) 2023; 11:2231. [PMID: 37628429 PMCID: PMC10454585 DOI: 10.3390/healthcare11162231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/31/2023] [Accepted: 08/05/2023] [Indexed: 08/27/2023] Open
Abstract
Cerebrovascular Reactivity (CVR) is a provocative test used with Blood oxygenation level-dependent (BOLD) Magnetic Resonance Imaging (MRI) studies, where a vasoactive stimulus is applied and the corresponding changes in the cerebral blood flow (CBF) are measured. The most common clinical application is the assessment of cerebral perfusion insufficiency in patients with steno-occlusive disease (SOD). Globally, millions of people suffer from cerebrovascular diseases, and SOD is the most common cause of ischemic stroke. Therefore, CVR analyses can play a vital role in early diagnosis and guiding clinical treatment. This study develops a convolutional neural network (CNN)-based clinical decision support system to facilitate the screening of SOD patients by discriminating between healthy and unhealthy CVR maps. The networks were trained on a confidential CVR dataset with two classes: 68 healthy control subjects, and 163 SOD patients. This original dataset was distributed in a ratio of 80%-10%-10% for training, validation, and testing, respectively, and image augmentations were applied to the training and validation sets. Additionally, some popular pre-trained networks were imported and customized for the objective classification task to conduct transfer learning experiments. Results indicate that a customized CNN with a double-stacked convolution layer architecture produces the best results, consistent with expert clinical readings.
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Affiliation(s)
- Yashesh Dasari
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
| | - James Duffin
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Anesthesia and Pain Management, University Health Network, Toronto, ON M5G 2C4, Canada
| | - Ece Su Sayin
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Anesthesia and Pain Management, University Health Network, Toronto, ON M5G 2C4, Canada
| | - Harrison T. Levine
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Anesthesia and Pain Management, University Health Network, Toronto, ON M5G 2C4, Canada
| | - Julien Poublanc
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, ON M5G 2C4, Canada
| | - Andrea E. Para
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, ON M5G 2C4, Canada
| | - David J. Mikulis
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, ON M5G 2C4, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Joseph A. Fisher
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Anesthesia and Pain Management, University Health Network, Toronto, ON M5G 2C4, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Olivia Sobczyk
- Department of Anesthesia and Pain Management, University Health Network, Toronto, ON M5G 2C4, Canada
- Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, ON M5G 2C4, Canada
| | - Mir Behrad Khamesee
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
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11
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Corkery AT, Miller KB, Loeper CA, Tetri LH, Pearson AG, Loggie NA, Howery AJ, Eldridge MW, Barnes JN. Association between serum prostacyclin and cerebrovascular reactivity in healthy young and older adults. Exp Physiol 2023; 108:1047-1056. [PMID: 37170828 PMCID: PMC10524213 DOI: 10.1113/ep090903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 04/17/2023] [Indexed: 05/13/2023]
Abstract
NEW FINDINGS What is the central question of this study? What is the relationship between prostacyclin and cerebrovascular reactivity to hypercapnia before and after administration of a cyclooxygenase inhibitor, indomethacin, in healthy young and older adults? What is the main finding and importance? Serum prostacyclin was not related to cerebrovascular reactivity to hypercapnia before or after administration of indomethacin. However, in older adults, serum prostacyclin was related to the magnitude of change in cerebrovascular reactivity from before to after indomethacin administration. This suggests that older adults with higher serum prostacyclin may rely more on cyclooxygenase products to mediate cerebrovascular reactivity. ABSTRACT Platelet activation may contribute to age-related cerebrovascular dysfunction by interacting with the endothelial cells that regulate the response to vasodilatory stimuli. This study evaluated the relationship between a platelet inhibitor, prostacyclin, and cerebrovascular reactivity (CVR) in healthy young (n = 35; 25 ± 4 years; 17 women, 18 men) and older (n = 12; 62 ± 2 years; 8 women, 4 men) adults, who were not daily aspirin users, before and after cyclooxygenase inhibition. Prostacyclin was determined by levels of 6-keto-prostaglandin F1α (6-keto PGF1α) in the blood. CVR was assessed by measuring the middle cerebral artery blood velocity response to hypercapnia using transcranial Doppler ultrasound before (CON) and 90 min after cyclooxygenase inhibition with indomethacin (INDO). In young adults, there were no associations between prostacyclin and middle cerebral artery CVR during CON (r = -0.14, P = 0.415) or INDO (r = 0.27, P = 0.118). In older adults, associations between prostacyclin and middle cerebral artery CVR during CON (r = 0.53, P = 0.075) or INDO (r = -0.45, P = 0.136) did not reach the threshold for significance. We also evaluated the relationship between prostacyclin and the change in CVR between conditions (ΔCVR). We found no association between ΔCVR and prostacyclin in young adults (r = 0.27, P = 0.110); however, in older adults, those with higher baseline prostacyclin levels demonstrated significantly greater ΔCVR (r = -0.74, P = 0.005). In conclusion, older adults with higher serum prostacyclin, a platelet inhibitor, may rely more on cyclooxygenase products for cerebrovascular reactivity to hypercapnia.
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Affiliation(s)
- Adam T Corkery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Kathleen B Miller
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Carissa A Loeper
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Laura H Tetri
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Andrew G Pearson
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Nicole A Loggie
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Anna J Howery
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
| | - Marlowe W Eldridge
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jill N Barnes
- Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin Madison, Madison, WI, USA
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12
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Crouch EE, Joseph T, Marsan E, Huang EJ. Disentangling brain vasculature in neurogenesis and neurodegeneration using single-cell transcriptomics. Trends Neurosci 2023; 46:551-565. [PMID: 37210315 PMCID: PMC10560453 DOI: 10.1016/j.tins.2023.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/15/2023] [Accepted: 04/26/2023] [Indexed: 05/22/2023]
Abstract
The vasculature is increasingly recognized to impact brain function in health and disease across the life span. During embryonic brain development, angiogenesis and neurogenesis are tightly coupled, coordinating the proliferation, differentiation, and migration of neural and glial progenitors. In the adult brain, neurovascular interactions continue to play essential roles in maintaining brain function and homeostasis. This review focuses on recent advances that leverage single-cell transcriptomics of vascular cells to uncover their subtypes, their organization and zonation in the embryonic and adult brain, and how dysfunction in neurovascular and gliovascular interactions contributes to the pathogenesis of neurodegenerative diseases. Finally, we highlight key challenges for future research in neurovascular biology.
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Affiliation(s)
- Elizabeth E Crouch
- Department of Pediatrics, University of California San Francisco, San Francisco, CA 94143, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94143, USA.
| | - Tara Joseph
- Department of Pediatrics, University of California San Francisco, San Francisco, CA 94143, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94143, USA
| | - Elise Marsan
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94143, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Eric J Huang
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA 94143, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94143, USA; Pathology Service (113B), San Francisco Veterans Administration Health Care System, San Francisco, CA 94121, USA.
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13
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Ogoh S, Watanabe H, Saito S, Fisher JP, Iwamoto E. Can Alterations in Cerebrovascular CO 2 Reactivity Be Identified Using Transfer Function Analysis without the Requirement for Carbon Dioxide Inhalation? J Clin Med 2023; 12:jcm12062441. [PMID: 36983441 PMCID: PMC10051076 DOI: 10.3390/jcm12062441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/09/2023] [Accepted: 03/21/2023] [Indexed: 03/30/2023] Open
Abstract
The present study aimed to examine the validity of a novel method to assess cerebrovascular carbon dioxide (CO2) reactivity (CVR) that does not require a CO2 inhalation challenge, e.g., for use in patients with respiratory disease or the elderly, etc. In twenty-one healthy participants, CVR responses to orthostatic stress (50° head-up tilt, HUT) were assessed using two methods: (1) the traditional CO2 inhalation method, and (2) transfer function analysis (TFA) between middle cerebral artery blood velocity (MCA V) and predicted arterial partial pressure of CO2 (PaCO2) during spontaneous respiration. During HUT, MCA V steady-state (i.e., magnitude) and MCA V onset (i.e., time constant) responses to CO2 inhalation were decreased (p < 0.001) and increased (p = 0.001), respectively, indicative of attenuated CVR. In contrast, TFA gain in the very low-frequency range (VLF, 0.005-0.024 Hz) was unchanged, while the TFA phase in the VLF approached zero during HUT (-0.38 ± 0.59 vs. 0.31 ± 0.78 radians, supine vs. HUT; p = 0.003), indicative of a shorter time (i.e., improved) response of CVR. These findings indicate that CVR metrics determined by TFA without a CO2 inhalation do not track HUT-evoked reductions in CVR identified using CO2 inhalation, suggesting that enhanced cerebral blood flow response to a change in CO2 using CO2 inhalation is necessary to assess CVR adequately.
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Affiliation(s)
- Shigehiko Ogoh
- Department of Biomedical Engineering, Toyo University, Kawagoe 350-8585, Japan
- Neurovascular Research Laboratory, University of South Wales, Pontypridd CF37 1DL, UK
| | - Hironori Watanabe
- Department of Biomedical Engineering, Toyo University, Kawagoe 350-8585, Japan
| | - Shotaro Saito
- Department of Biomedical Engineering, Toyo University, Kawagoe 350-8585, Japan
| | - James P Fisher
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand
| | - Erika Iwamoto
- School of Health Sciences, Sapporo Medical University, Sapporo 060-8556, Japan
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14
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Wang C, Reid G, Mackay CE, Hayes G, Bulte DP, Suri S. A Systematic Review of the Association Between Dementia Risk Factors and Cerebrovascular Reactivity. Neurosci Biobehav Rev 2023; 148:105140. [PMID: 36944391 DOI: 10.1016/j.neubiorev.2023.105140] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 02/15/2023] [Accepted: 03/15/2023] [Indexed: 03/23/2023]
Abstract
Cumulative evidence suggests that impaired cerebrovascular reactivity (CVR), a regulatory response critical for maintaining neuronal health, is amongst the earliest pathological changes in dementia. However, we know little about how CVR is affected by dementia risk, prior to disease onset. Understanding this relationship would improve our knowledge of disease pathways and help inform preventative interventions. This systematic review investigates 59 studies examining how CVR (measured by magnetic resonance imaging) is affected by modifiable, non-modifiable, and clinical risk factors for dementia. We report that non-modifiable risk (older age and apolipoprotein ε4), some modifiable factors (diabetes, traumatic brain injury, hypertension) and some clinical factors (stroke, carotid artery occlusion, stenosis) were consistently associated with reduced CVR. We also note a lack of conclusive evidence on how other behavioural factors such as physical inactivity, obesity, or depression, affect CVR. This review explores the biological mechanisms underpinning these brain- behaviour associations, highlights evident gaps in the literature, and identifies the risk factors that could be managed to preserve CVR in an effort to prevent dementia.
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Affiliation(s)
- Congxiyu Wang
- Department of Psychiatry, University of Oxford, UK; Wellcome Centre for Integrative Neuroimaging, University of Oxford, UK
| | - Graham Reid
- Department of Psychiatry, University of Oxford, UK; Department of Experimental Psychology, University of Oxford, UK
| | - Clare E Mackay
- Department of Psychiatry, University of Oxford, UK; Wellcome Centre for Integrative Neuroimaging, University of Oxford, UK
| | - Genevieve Hayes
- Institute of Biomedical Engineering, University of Oxford, UK
| | - Daniel P Bulte
- Institute of Biomedical Engineering, University of Oxford, UK
| | - Sana Suri
- Department of Psychiatry, University of Oxford, UK; Wellcome Centre for Integrative Neuroimaging, University of Oxford, UK.
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15
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Saka E, Atay LO, Akdemir UO, Yetim E, Balci E, Arsava EM, Topcuoglu MA. Cerebral vasomotor reactivity across the continuum of subjective cognitive impairment, amnestic mild cognitive impairment and probable Alzheimer's dementia: A transcranial Doppler and PET/MRI study. J Cereb Blood Flow Metab 2023; 43:129-137. [PMID: 36314070 PMCID: PMC9875349 DOI: 10.1177/0271678x221124656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/28/2022] [Accepted: 07/31/2022] [Indexed: 12/12/2022]
Abstract
Cerebrovascular dysfunction has been suggested as a physiomarker of Alzheimer's disease (AD)-associated neuronal degeneration, but the underlying mechanisms are still debated. Herein cerebral vasomotor reactivity (VMR, breath-hold index: BHI), metabolic activity (lobar SUVs, FDG PET MRI), amyloid load (Centiloid score, Flutemetamol PET MRI), hemispheric cortical thickness, white matter lesion load and cerebral blood flow (ASL) were studied in 43 consecutive subjects (mean age: 64 years, female 13), diagnosed with subjective cognitive impairment (SCI, n = 10), amnestic mild cognitive impairment (aMCI, n = 15), and probable Alzheimer's dementia (AD, n = 18). BHI was significantly reduced in AD and aMCI patients compared to SCI subjects. A highly significant inverse correlation was found between BHI and the centiloid score (r = -0.648, p < 0.001). There was moderate positive correlation between BHI and frontal, temporal and parietal FDG SUV and ASL values, and a borderline negative correlation with age and white matter lesion volume. The link between amyloid burden and VMR was independent and strong in linear regression models where all these parameters were included (β from -0.580 to -0.476, p < 0.001). In conclusion, our study confirms the negative association of cerebral amyloid accumulation and vasomotor reactivity in Alzheimer's disease with the most direct data to date in humans.
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Affiliation(s)
- Esen Saka
- Faculty of Medicine, Department of Neurology, Hacettepe
University, Ankara, Turkey
| | - Lutfiye Ozlem Atay
- Faculty of Medicine, Department of Nuclear Medicine, Gazi
University, Ankara, Turkey
| | - Umit Ozgur Akdemir
- Faculty of Medicine, Department of Nuclear Medicine, Gazi
University, Ankara, Turkey
| | - Ezgi Yetim
- Faculty of Medicine, Department of Neurology, Hacettepe
University, Ankara, Turkey
| | - Erdem Balci
- Faculty of Medicine, Department of Nuclear Medicine, Gazi
University, Ankara, Turkey
| | - Ethem Murat Arsava
- Faculty of Medicine, Department of Neurology, Hacettepe
University, Ankara, Turkey
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16
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Shams S, Prokopiou P, Esmaelbeigi A, Mitsis GD, Chen JJ. Modeling the dynamics of cerebrovascular reactivity to carbon dioxide in fMRI under task and resting-state conditions. Neuroimage 2023; 265:119758. [PMID: 36442732 DOI: 10.1016/j.neuroimage.2022.119758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 11/11/2022] [Accepted: 11/18/2022] [Indexed: 11/26/2022] Open
Abstract
Conventionally, cerebrovascular reactivity (CVR) is estimated as the amplitude of the hemodynamic response to vascular stimuli, most commonly carbon dioxide (CO2). While the CVR amplitude has established clinical utility, the temporal characteristics of CVR (dCVR) have been increasingly explored and may yield even more pathology-sensitive parameters. This work is motivated by the current need to evaluate the feasibility of dCVR modeling in various experimental conditions. In this work, we present a comparison of several recently published/utilized model-based deconvolution (response estimation) approaches for estimating the CO2 response function h(t), including maximum a posteriori likelihood (MAP), inverse logit (IL), canonical correlation analysis (CCA), and basis expansion (using Gamma and Laguerre basis sets). To aid the comparison, we devised a novel simulation framework that incorporates a wide range of SNRs, ranging from 10 to -7 dB, representative of both task and resting-state CO2 changes. In addition, we built ground-truth h(t) into our simulation framework, overcoming the conventional limitation that the true h(t) is unknown. Moreover, to best represent realistic noise found in fMRI scans, we extracted noise from in-vivo resting-state scans. Furthermore, we introduce a simple optimization of the CCA method (CCAopt) and compare its performance to these existing methods. Our findings suggest that model-based methods can accurately estimate dCVR even amidst high noise (i.e. resting-state), and in a manner that is largely independent of the underlying model assumptions for each method. We also provide a quantitative basis for making methodological choices, based on the desired dCVR parameters, the estimation accuracy and computation time. The BEL method provided the highest accuracy and robustness, followed by the CCAopt and IL methods. Of the three, the CCAopt method has the lowest computational requirements. These findings lay the foundation for wider adoption of dCVR estimation in CVR mapping.
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Affiliation(s)
- Seyedmohammad Shams
- Rotman Research Institute, Baycrest Health Sciences, Canada; Department of Neurology, Henry Ford Health, USA
| | - Prokopis Prokopiou
- Department of Radiology, Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | | | - J Jean Chen
- Rotman Research Institute, Baycrest Health Sciences, Canada; Department of Bioengineering, McGill University, Canada; Department of Medical Biophysics, University of Toronto, Canada; Institute of Biomedical Engineering, University of Toronto, Canada.
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17
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Jack J, Woodgates A, Smail O, Brown F, Lynam K, Lester A, Williams G, Bond B. Cerebral blood flow regulation is not acutely altered after a typical number of headers in women footballers. Front Neurol 2022; 13:1021536. [PMID: 36479047 PMCID: PMC9719992 DOI: 10.3389/fneur.2022.1021536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/31/2022] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND The repeated act of heading has been implicated in the link between football participation and risk of neurodegenerative disease, and acutely alters cerebrovascular outcomes in men. This study assessed whether exposure to a realistic number of headers acutely influences indices of cerebral blood flow regulation in female footballers. METHODS Nineteen female players completed a heading trial and seated control trial on two separate days. The heading trial involved six headers in 1 h (one every 10 min), with the ball traveling at 40 ± 5 km/h. Cerebrovascular reactivity to hypercapnia and hypocapnia was determined using serial breath holding and hyperventilation attempts. Dynamic cerebral autoregulation (dCA) was assessed by scrutinizing the relationship between cerebral blood flow and mean arterial blood pressure during 5 min of squat stand maneuvers at 0.05 Hz. Neurovascular coupling (NVC) was quantified as the posterior cerebral artery blood velocity response to a visual search task. These outcomes were assessed before and 1 h after the heading or control trial. RESULTS No significant time by trial interaction was present for the hypercapnic (P = 0.48,η p 2 = 0.05) and hypocapnic (P = 0.47,η p 2 = 0.06) challenge. Similarly, no significant interaction effect was present for any metric of dCA (P > 0.12,η p 2 < 0.16 for all) or NVC (P > 0.14,η p 2 < 0.15 for all). CONCLUSION The cerebral blood flow response to changes in carbon dioxide, blood pressure and a visual search task were not altered following six headers in female footballers. Further study is needed to observe whether changes are apparent after more prolonged exposure.
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Affiliation(s)
| | | | | | | | | | | | | | - Bert Bond
- Exeter Head Impacts, Brain Injury and Trauma (ExHIBIT) Research Group, Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
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18
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Hayes G, Pinto J, Sparks SN, Wang C, Suri S, Bulte DP. Vascular smooth muscle cell dysfunction in neurodegeneration. Front Neurosci 2022; 16:1010164. [PMID: 36440263 PMCID: PMC9684644 DOI: 10.3389/fnins.2022.1010164] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/24/2022] [Indexed: 09/01/2023] Open
Abstract
Vascular smooth muscle cells (VSMCs) are the key moderators of cerebrovascular dynamics in response to the brain's oxygen and nutrient demands. Crucially, VSMCs may provide a sensitive biomarker for neurodegenerative pathologies where vasculature is compromised. An increasing body of research suggests that VSMCs have remarkable plasticity and their pathophysiology may play a key role in the complex process of neurodegeneration. Furthermore, extrinsic risk factors, including environmental conditions and traumatic events can impact vascular function through changes in VSMC morphology. VSMC dysfunction can be characterised at the molecular level both preclinically, and clinically ex vivo. However the identification of VSMC dysfunction in living individuals is important to understand changes in vascular function at the onset and progression of neurological disorders such as dementia, Alzheimer's disease, and Parkinson's disease. A promising technique to identify changes in the state of cerebral smooth muscle is cerebrovascular reactivity (CVR) which reflects the intrinsic dynamic response of blood vessels in the brain to vasoactive stimuli in order to modulate regional cerebral blood flow (CBF). In this work, we review the role of VSMCs in the most common neurodegenerative disorders and identify physiological systems that may contribute to VSMC dysfunction. The evidence collected here identifies VSMC dysfunction as a strong candidate for novel therapeutics to combat the development and progression of neurodegeneration, and highlights the need for more research on the role of VSMCs and cerebrovascular dynamics in healthy and diseased states.
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Affiliation(s)
- Genevieve Hayes
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Joana Pinto
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Sierra N. Sparks
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Congxiyu Wang
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
| | - Sana Suri
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
| | - Daniel P. Bulte
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
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19
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Glodzik L, Rusinek H, Butler T, Li Y, Storey P, Sweeney E, Osorio RS, Biskaduros A, Tanzi E, Harvey P, Woldstad C, Maloney T, de Leon MJ. Higher body mass index is associated with worse hippocampal vasoreactivity to carbon dioxide. Front Aging Neurosci 2022; 14:948470. [PMID: 36158536 PMCID: PMC9491849 DOI: 10.3389/fnagi.2022.948470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/22/2022] [Indexed: 11/24/2022] Open
Abstract
Background and objectives Obesity is a risk factor for cognitive decline. Probable mechanisms involve inflammation and cerebrovascular dysfunction, leading to diminished cerebral blood flow (CBF) and cerebrovascular reactivity (CVR). The hippocampus, crucially involved in memory processing and thus relevant to many types of dementia, poses a challenge in studies of perfusion and CVR, due to its location, small size, and complex shape. We examined the relationships between body mass index (BMI) and hippocampal resting CBF and CVR to carbon dioxide (CVRCO2) in a group of cognitively normal middle-aged and older adults. Methods Our study was a retrospective analysis of prospectively collected data. Subjects were enrolled for studies assessing the role of hippocampal hemodynamics as a biomarker for AD among cognitively healthy elderly individuals (age > 50). Participants without cognitive impairment, stroke, and active substance abuse were recruited between January 2008 and November 2017 at the NYU Grossman School of Medicine, former Center for Brain Health. All subjects underwent medical, psychiatric, and neurological assessments, blood tests, and MRI examinations. To estimate CVR, we increased their carbon dioxide levels using a rebreathing protocol. Relationships between BMI and brain measures were tested using linear regression. Results Our group (n = 331) consisted of 60.4% women (age 68.8 ± 7.5 years; education 16.8 ± 2.2 years) and 39.6% men (age 70.4 ± 6.4 years; education 16.9 ± 2.4 years). Approximately 22% of them (n = 73) were obese. BMI was inversely associated with CVRCO2 (β = -0.12, unstandardized B = -0.06, 95% CI -0.11, -0.004). A similar relationship was observed after excluding subjects with diabetes and insulin resistance (β = -0.15, unstandardized B = -0.08, 95% CI -0.16, -0.000). In the entire group, BMI was more strongly related to hippocampal CVRCO2 in women (β = -0.20, unstandardized B = -0.08, 95% CI -0.13, -0.02). Discussion These findings lend support to the notion that obesity is a risk factor for hippocampal hemodynamic impairment and suggest targeting obesity as an important prevention strategy. Prospective studies assessing the effects of weight loss on brain hemodynamic measures and inflammation are warranted.
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Affiliation(s)
- Lidia Glodzik
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Henry Rusinek
- Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Tracy Butler
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Yi Li
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Pippa Storey
- Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Elizabeth Sweeney
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Ricardo S. Osorio
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
| | - Adrienne Biskaduros
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Emily Tanzi
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Patrick Harvey
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Christopher Woldstad
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Thomas Maloney
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Mony J. de Leon
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
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20
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Vestergaard MB, Frederiksen JL, Larsson HBW, Cramer SP. Cerebrovascular Reactivity and Neurovascular Coupling in Multiple Sclerosis-A Systematic Review. Front Neurol 2022; 13:912828. [PMID: 35720104 PMCID: PMC9198441 DOI: 10.3389/fneur.2022.912828] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/04/2022] [Indexed: 11/25/2022] Open
Abstract
The inflammatory processes observed in the central nervous system in multiple sclerosis (MS) could damage the endothelium of the cerebral vessels and lead to a dysfunctional regulation of vessel tonus and recruitment, potentially impairing cerebrovascular reactivity (CVR) and neurovascular coupling (NVC). Impaired CVR or NVC correlates with declining brain health and potentially plays a causal role in the development of neurodegenerative disease. Therefore, we examined studies on CVR or NVC in MS patients to evaluate the evidence for impaired cerebrovascular function as a contributing disease mechanism in MS. Twenty-three studies were included (12 examined CVR and 11 examined NVC). Six studies found no difference in CVR response between MS patients and healthy controls. Five studies observed reduced CVR in patients. This discrepancy can be because CVR is mainly affected after a long disease duration and therefore is not observed in all patients. All studies used CO2 as a vasodilating stimulus. The studies on NVC demonstrated diverse results; hence a conclusion that describes all the published observations is difficult to find. Future studies using quantitative techniques and larger study samples are needed to elucidate the discrepancies in the reported results.
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Affiliation(s)
- Mark B Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Jette L Frederiksen
- Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Henrik B W Larsson
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark.,Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Stig P Cramer
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
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21
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Subclinical cognitive deficits are associated with reduced cerebrovascular response to visual stimulation in mid-sixties men. GeroScience 2022; 44:1905-1923. [PMID: 35648331 DOI: 10.1007/s11357-022-00596-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/22/2022] [Indexed: 11/04/2022] Open
Abstract
Reduced cerebrovascular response to neuronal activation is observed in patients with neurodegenerative disease. In the present study, we examined the correlation between reduced cerebrovascular response to visual activation (ΔCBFVis.Act) and subclinical cognitive deficits in a human population of mid-sixties individuals without neurodegenerative disease. Such a correlation would suggest that impaired cerebrovascular function occurs before overt neurodegenerative disease. A total of 187 subjects (age 64-67 years) of the Metropolit Danish Male Birth Cohort participated in the study. ΔCBFVis.Act was measured using arterial spin labelling (ASL) MRI. ΔCBFVis.Act correlated positively with cognitive performance in: Global cognition (p = 0.046), paired associative memory (p = 0.025), spatial recognition (p = 0.026), planning (p = 0.016), simple processing speed (p < 0.01), and with highly significant correlations with current intelligence (p < 10-5), and more complex processing speed (p < 10-3), the latter two explaining approximately 11-13% of the variance. Reduced ΔCBFVis.Act was independent of brain atrophy. Our findings suggest that inhibited cerebrovascular response to neuronal activation is an early deficit in the ageing brain and associated with subclinical cognitive deficits. Cerebrovascular dysfunction could be an early sign of a trajectory pointing towards the development of neurodegenerative disease. Future efforts should elucidate if maintenance of a healthy cerebrovascular function can protect against the development of dementia.
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22
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Beaudin AE, McCreary CR, Mazerolle EL, Gee M, Sharma B, Subotic A, Zwiers AM, Cox E, Nelles K, Charlton A, Frayne R, Ismail Z, Beaulieu C, Jickling G, Camicioli RM, Pike GB, Smith E. Cerebrovascular Reactivity Across the Entire Brain in Cerebral Amyloid Angiopathy. Neurology 2022; 98:e1716-e1728. [PMID: 35210294 PMCID: PMC9071369 DOI: 10.1212/wnl.0000000000200136] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 01/18/2022] [Indexed: 11/25/2022] Open
Abstract
Background and Objectives Reduced cerebrovascular reactivity is proposed to be a feature of cerebral amyloid angiopathy (CAA) but has not been measured directly. Employing a global vasodilatory stimulus (hypercapnia), this study assessed the relationships between cerebrovascular reactivity and MRI markers of CAA and cognitive function. Methods In a cross-sectional study, individuals with probable CAA, mild cognitive impairment, or dementia due to Alzheimer disease and healthy controls underwent neuropsychological testing and an MRI that included a 5% carbon dioxide challenge. Cerebrovascular reactivity was compared across groups controlling for age, sex, and the presence of hypertension, and its associations with MRI markers of CAA in participants with CAA and with cognition across all participants were determined using multivariable linear regression adjusting for group, age, sex, education, and the presence of hypertension. Results Cerebrovascular reactivity data (mean ± SD) were available for 26 participants with CAA (9 female; 74.4 ± 7.7 years), 19 participants with mild cognitive impairment (5 female; 72.1 ± 8.5 years), 12 participants with dementia due to Alzheimer disease (4 female; 69.4 ± 6.6 years), and 39 healthy controls (30 female; 68.8 ± 5.4 years). Gray and whiter matter reactivity averaged across the entire brain was lower in participants with CAA and Alzheimer disease dementia compared to healthy controls, with a predominantly posterior distribution of lower reactivity in both groups. Higher white matter hyperintensity volume was associated with lower white matter reactivity (standardized coefficient [β], 95% CI −0.48, −0.90 to −0.01). Higher gray matter reactivity was associated with better global cognitive function (β 0.19, 0.03–0.36), memory (β 0.21, 0.07–0.36), executive function (β 0.20, 0.02–0.39), and processing speed (β 0.27, 0.10–0.45) and higher white matter reactivity was associated with higher memory (β 0.22, 0.08–0.36) and processing speed (β 0.23, 0.06–0.40). Conclusions Reduced cerebrovascular reactivity is a core feature of CAA and its assessment may provide an additional biomarker for disease severity and cognitive impairment.
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Affiliation(s)
- Andrew E Beaudin
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada .,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Cheryl R McCreary
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Radiology, University of Calgary, Calgary, AB, Canada.,Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Calgary, AB, Canada
| | - Erin L Mazerolle
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Radiology, University of Calgary, Calgary, AB, Canada.,Department of Psychology, St. Francis Xavier University, Antigonish, NS, Canada
| | - Myrlene Gee
- Division of Neurology and Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Breni Sharma
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Arsenije Subotic
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Angela M Zwiers
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Emily Cox
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Krista Nelles
- Division of Neurology and Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Anna Charlton
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Richard Frayne
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Radiology, University of Calgary, Calgary, AB, Canada.,Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Calgary, AB, Canada
| | - Zahinoor Ismail
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Psychiatry, University of Calgary, Calgary, AB, Canada.,Mathison Centre for Mental Health Research & Education, University of Calgary, Calgary, AB, Canada
| | - Christian Beaulieu
- Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada
| | - Glen Jickling
- Division of Neurology and Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Richard M Camicioli
- Division of Neurology and Department of Medicine, University of Alberta, Edmonton, AB, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - G Bruce Pike
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Radiology, University of Calgary, Calgary, AB, Canada.,Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Calgary, AB, Canada
| | - Eric Smith
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Radiology, University of Calgary, Calgary, AB, Canada.,Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Calgary, AB, Canada
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23
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Vemuri P, Decarli CS, Duering M. Imaging Markers of Vascular Brain Health: Quantification, Clinical Implications, and Future Directions. Stroke 2022; 53:416-426. [PMID: 35000423 PMCID: PMC8830603 DOI: 10.1161/strokeaha.120.032611] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cerebrovascular disease (CVD) manifests through a broad spectrum of mechanisms that negatively impact brain and cognitive health. Oftentimes, CVD changes (excluding acute stroke) are insufficiently considered in aging and dementia studies which can lead to an incomplete picture of the etiologies contributing to the burden of cognitive impairment. Our goal with this focused review is 3-fold. First, we provide a research update on the current magnetic resonance imaging methods that can measure CVD lesions as well as early CVD-related brain injury specifically related to small vessel disease. Second, we discuss the clinical implications and relevance of these CVD imaging markers for cognitive decline, incident dementia, and disease progression in Alzheimer disease, and Alzheimer-related dementias. Finally, we present our perspective on the outlook and challenges that remain in the field. With the increased research interest in this area, we believe that reliable CVD imaging biomarkers for aging and dementia studies are on the horizon.
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Affiliation(s)
| | - Charles S. Decarli
- Departments of Neurology and Center for Neuroscience, University of California at Davis, Sacramento, California, USA
| | - Marco Duering
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Germany
- Medical Image Analysis Center (MIAC AG) and qbig, Department of Biomedical Engineering, University of Basel, Switzerland
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24
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Warner L, Bach-Hagemann A, Albanna W, Clusmann H, Schubert GA, Lindauer U, Conzen-Dilger C. Vascular Reactivity to Hypercapnia Is Impaired in the Cerebral and Retinal Vasculature in the Acute Phase After Experimental Subarachnoid Hemorrhage. Front Neurol 2022; 12:757050. [PMID: 35095718 PMCID: PMC8793938 DOI: 10.3389/fneur.2021.757050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: Impaired cerebral blood flow (CBF) regulation, such as reduced reactivity to hypercapnia, contributes to the pathophysiology after aneurysmal subarachnoid hemorrhage (SAH), but temporal dynamics in the acute phase are unknown. Featuring comparable molecular regulation mechanisms, the retinal vessels participate in chronic and subacute stroke- and SAH-associated vessel alterations in patients and can be studied non-invasively. This study is aimed to characterize the temporal course of the cerebral and retinal vascular reactivity to hypercapnia in the acute phase after experimental SAH and compare the potential degree of impairment.Methods: Subarachnoid hemorrhage was induced by injecting 0.5 ml of heparinized autologous blood into the cisterna magna of male Wistar rats using two anesthesia protocols [isoflurane/fentanyl n = 25 (Sham + SAH): Iso—Group, ketamine/xylazine n = 32 (Sham + SAH): K/X—Group]. CBF (laser speckle contrast analysis) and physiological parameters were measured continuously for 6 h. At six predefined time points, hypercapnia was induced by hypoventilation controlled via blood gas analysis, and retinal vessel diameter (RVD) was determined non-invasively.Results: Cerebral reactivity and retinal reactivity in Sham groups were stable with only a slight attenuation after 2 h in RVD of the K/X—Group. In the SAH Iso—Group, cerebral and retinal CO2 reactivity compared to baseline was immediately impaired starting at 30 min after SAH (CBF p = 0.0090, RVD p = 0.0135) and lasting up to 4 h (p = 0.0136, resp. p = 0.0263). Similarly, in the K/X—Group, cerebral CO2 reactivity was disturbed early after SAH (30 min, p = 0.003) albeit showing a recovery to baseline after 2 h while retinal CO2 reactivity was impaired over the whole observation period (360 min, p = 0.0001) in the K/X—Group. After normalization to baseline, both vascular beds showed a parallel behavior regarding the temporal course and extent of impairment.Conclusion: This study provides a detailed temporal analysis of impaired cerebral vascular CO2 reactivity starting immediately after SAH and lasting up to 6 h. Importantly, the retinal vessels participate in these acute changes underscoring the promising role of the retina as a potential non-invasive screening tool after SAH. Further studies will be required to determine the correlation with functional outcomes.
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Affiliation(s)
- Laura Warner
- Translational Neurosurgery and Neurobiology, Department of Neurosurgery, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Annika Bach-Hagemann
- Translational Neurosurgery and Neurobiology, Department of Neurosurgery, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Walid Albanna
- Department of Neurosurgery, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Hans Clusmann
- Department of Neurosurgery, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Gerrit A. Schubert
- Department of Neurosurgery, Medical Faculty, RWTH Aachen University, Aachen, Germany
- Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland
| | - Ute Lindauer
- Translational Neurosurgery and Neurobiology, Department of Neurosurgery, Medical Faculty, RWTH Aachen University, Aachen, Germany
- Department of Neurosurgery, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Catharina Conzen-Dilger
- Department of Neurosurgery, Medical Faculty, RWTH Aachen University, Aachen, Germany
- *Correspondence: Catharina Conzen-Dilger
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25
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Tomoto T, Tarumi T, Chen J, Pasha EP, Cullum CM, Zhang R. Cerebral Vasomotor Reactivity in Amnestic Mild Cognitive Impairment. J Alzheimers Dis 2021; 77:191-202. [PMID: 32716360 DOI: 10.3233/jad-200194] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Cerebral blood flow (CBF) is sensitive to changes in arterial CO2, referred to as cerebral vasomotor reactivity (CVMR). Whether CVMR is altered in patients with amnestic mild cognitive impairment (aMCI), a prodromal stage of Alzheimer disease (AD), is unclear. OBJECTIVE To determine whether CVMR is altered in aMCI and is associated with cognitive performance. METHODS Fifty-three aMCI patients aged 55 to 80 and 22 cognitively normal subjects (CN) of similar age, sex, and education underwent measurements of CBF velocity (CBFV) with transcranial Doppler and end-tidal CO2 (EtCO2) with capnography during hypocapnia (hyperventilation) and hypercapnia (rebreathing). Arterial pressure (BP) was measured to calculate cerebrovascular conductance (CVCi) to normalize the effect of changes in BP on CVMR assessment. Cognitive function was assessed with Mini-Mental State Examination (MMSE) and neuropsychological tests focused on memory (Logical Memory, California Verbal Learning Test) and executive function (Delis-Kaplan Executive Function Scale; DKEFS). RESULTS At rest, CBFV and MMSE did not differ between groups. CVMR was reduced by 13% in CBFV% and 21% in CVCi% during hypocapnia and increased by 22% in CBFV% and 20% in CVCi% during hypercapnia in aMCI when compared to CN (all p < 0.05). Logical Memory recall scores were positively correlated with hypocapnia (r = 0.283, r = 0.322, p < 0.05) and negatively correlated with hypercapnic CVMR measured in CVCi% (r = -0.347, r = -0.446, p < 0.01). Similar correlations were observed in D-KEFS Trail Making scores. CONCLUSION Altered CVMR in aMCI and its associations with cognitive performance suggests the presence of cerebrovascular dysfunction in older adults who have high risks for AD.
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Affiliation(s)
- Tsubasa Tomoto
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Takashi Tarumi
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
| | - Jason Chen
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
| | - Evan P Pasha
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - C Munro Cullum
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Rong Zhang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
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26
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Choi B, Crouzet C, Lau WL, Cribbs DH, Fisher MJ. Cerebral Blood Flow in Chronic Kidney Disease. J Stroke Cerebrovasc Dis 2021; 30:105702. [PMID: 33714675 PMCID: PMC8384649 DOI: 10.1016/j.jstrokecerebrovasdis.2021.105702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 02/17/2021] [Indexed: 12/27/2022] Open
Abstract
The prevalence of mild cognitive impairment increases with age and is further exacerbated by chronic kidney disease (CKD). CKD is associated with (1) mild cognitive impairment, (2) impaired endothelial function, (3) impaired blood-brain barrier, (4) increased cerebral microhemorrhage burden, (5) increased cerebral blood flow (CBF), (6) impaired cerebral autoregulation, (7) impaired cerebrovascular reactivity, and (8) increased arterial stiffness. We report preliminary findings from our group that demonstrate altered cerebrovascular reactivity in a mouse model of CKD-associated vascular calcification. The CBF of CKD mice increased more quickly in response to hypercapnia (p < 0.05) but then decreased prematurely during hypercapnia challenge (p < 0.05). Together, these results indicate that altered kidney function can lead to alterations in the cerebral microvasculature, and hence brain health.
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Affiliation(s)
- Bernard Choi
- Departments of Biomedical Engineering and Surgery, University of California, Irvine, CA, United States; Beckman Laser Institute and Medical Clinic, University of California, 1002 Health Sciences Road East, Irvine, CA 92612, United States; Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, CA, United States.
| | - Christian Crouzet
- Beckman Laser Institute and Medical Clinic, University of California, 1002 Health Sciences Road East, Irvine, CA 92612, United States; Department of Biomedical Engineering, University of California, Irvine, CA, United States.
| | - Wei Ling Lau
- Division of Nephrology, Department of Medicine, University of California, Orange, CA, United States.
| | - David H Cribbs
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, United States.
| | - Mark J Fisher
- Beckman Laser Institute and Medical Clinic, University of California, 1002 Health Sciences Road East, Irvine, CA 92612, United States; Department of Neurology, University of California Irvine, Orange, CA, United States.
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27
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Migdal KU, Robinson AT, Watso JC, Babcock MC, Lennon SL, Martens CR, Serrador JM, Farquhar WB. A high salt meal does not impair cerebrovascular reactivity in healthy young adults. Physiol Rep 2021; 8:e14585. [PMID: 33038066 PMCID: PMC7547584 DOI: 10.14814/phy2.14585] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/28/2020] [Accepted: 08/31/2020] [Indexed: 01/11/2023] Open
Abstract
A high sodium (Na+) meal impairs peripheral vascular function. In rodents, chronic high dietary Na+ impairs cerebral vascular function, and in humans, habitual high dietary Na+ is associated with increased stroke risk. However, the effects of acute high dietary Na+ on the cerebral vasculature in humans are unknown. The purpose of this study was to determine if acute high dietary Na+ impairs cerebrovascular reactivity in healthy adults. Thirty‐seven participants (20F/17M; 25 ± 5 years; blood pressure [BP]: 107 ± 9/61 ± 6 mm Hg) participated in this randomized, cross‐over study. Participants were given a low Na+ meal (LSM; 138 mg Na+) and a high Na+ meal (HSM; 1,495 mg Na+) separated by ≥ one week. Serum Na+, beat‐to‐beat BP, middle cerebral artery velocity (transcranial Doppler), and end‐tidal carbon dioxide (PETCO2) were measured pre‐ (baseline) and 60 min post‐prandial. Cerebrovascular reactivity was assessed by determining the percent change in middle cerebral artery velocity to hypercapnia (via 8% CO2, 21% oxygen, balance nitrogen) and hypocapnia (via mild hyperventilation). Peripheral vascular function was measured using brachial artery flow‐mediated dilation (FMD). Changes in serum Na+ were greater following the HSM (HSM: Δ1.6 ± 1.2 mmol/L vs. LSM: Δ0.7 ± 1.2 mmol/L, p < .01). Cerebrovascular reactivity to hypercapnia (meal effect: p = .41) and to hypocapnia (meal effect: p = .65) were not affected by the HSM. Contrary with previous findings, FMD was not reduced following the HSM (meal effect: p = .74). These data suggest that a single high Na+ meal does not acutely impair cerebrovascular reactivity, and suggests that despite prior findings, a single high Na+ meal does not impair peripheral vascular function in healthy adults.
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Affiliation(s)
- Kamila U Migdal
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, USA
| | - Austin T Robinson
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, USA
| | - Joseph C Watso
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, USA
| | - Matthew C Babcock
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, USA
| | - Shannon L Lennon
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, USA
| | - Christopher R Martens
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, USA
| | - Jorge M Serrador
- Department of Pharmacology, Physiology & Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - William B Farquhar
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, USA
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28
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Butler T, Goldberg JD, Galvin JE, Maloney T, Ravdin L, Glodzik L, de Leon MJ, Hochman T, Bowen RL, Atwood CS. Rationale, study design and implementation of the LUCINDA Trial: Leuprolide plus Cholinesterase Inhibition to reduce Neurologic Decline in Alzheimer's. Contemp Clin Trials 2021; 107:106488. [PMID: 34166841 PMCID: PMC8550816 DOI: 10.1016/j.cct.2021.106488] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 06/11/2021] [Accepted: 06/14/2021] [Indexed: 11/20/2022]
Abstract
The LUCINDA Trial (Leuprolide plus Cholinesterase Inhibition to reduce Neurologic Decline in Alzheimer's) is a 52 week, randomized, placebo-controlled trial of leuprolide acetate (Eligard) in women with Alzheimer's disease (AD). Leuprolide acetate is a gonadotropin analogue commonly used for hormone-sensitive conditions such as prostate cancer and endometriosis. This repurposed drug demonstrated efficacy in a previous Phase II clinical trial in those women with AD who also received a stable dose of the acetylcholinesterase inhibitor donepezil (Bowen et al., 2015). Basic biological, epidemiological and clinical trial data suggest leuprolide acetate mediates improvement and stabilization of neuropathology and cognitive performance via the modulation of gonadotropin and/or gonadotropin-releasing hormone signaling. LUCINDA will enroll 150 women with mild-moderate AD who are receiving a stable dose of donepezil from three study sites in the United States. Cognition and function are the primary outcome measures as assessed by the Alzheimer's Disease Assessment Scale-Cognitive Subscale. Blood and MRI biomarkers are also measured to assess hormonal, inflammatory and AD biomarker changes. We present the protocol for LUCINDA and discuss trial innovations and challenges including changes necessitated by the covid-19 pandemic and study drug procurement issues.
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Affiliation(s)
- Tracy Butler
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY 10021, USA.
| | - Judith D Goldberg
- Departments of Population Health and Environmental Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - James E Galvin
- Comprehensive Center for Brain Health, Departments of Neurology and Psychiatry, University of Miami, Miller School of Medicine, Boca Raton, FL 33433, USA
| | - Thomas Maloney
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lisa Ravdin
- Department of Neurology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lidia Glodzik
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Mony J de Leon
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY 10021, USA
| | - Tsivia Hochman
- Departments of Population Health and Environmental Medicine, New York University School of Medicine, New York, NY 10016, USA
| | | | - Craig S Atwood
- Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin School of Medicine and Public Health, and Geriatric Research, Education and Clinical Center, Veterans Administration Hospital, Madison, WI 53705, USA
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29
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Zimmerman B, Rypma B, Gratton G, Fabiani M. Age-related changes in cerebrovascular health and their effects on neural function and cognition: A comprehensive review. Psychophysiology 2021; 58:e13796. [PMID: 33728712 PMCID: PMC8244108 DOI: 10.1111/psyp.13796] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/11/2021] [Accepted: 02/08/2021] [Indexed: 12/11/2022]
Abstract
The process of aging includes changes in cellular biology that affect local interactions between cells and their environments and eventually propagate to systemic levels. In the brain, where neurons critically depend on an efficient and dynamic supply of oxygen and glucose, age-related changes in the complex interaction between the brain parenchyma and the cerebrovasculature have effects on health and functioning that negatively impact cognition and play a role in pathology. Thus, cerebrovascular health is considered one of the main mechanisms by which a healthy lifestyle, such as habitual cardiorespiratory exercise and a healthful diet, could lead to improved cognitive outcomes with aging. This review aims at detailing how the physiology of the cerebral vascular system changes with age and how these changes lead to differential trajectories of cognitive maintenance or decline. This provides a framework for generating specific mechanistic hypotheses about the efficacy of proposed interventions and lifestyle covariates that contribute to enhanced cognitive well-being. Finally, we discuss the methodological implications of age-related changes in the cerebral vasculature for human cognitive neuroscience research and propose directions for future experiments aimed at investigating age-related changes in the relationship between physiology and cognitive mechanisms.
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Affiliation(s)
- Benjamin Zimmerman
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gabriele Gratton
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Monica Fabiani
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
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30
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Tomoto T, Tarumi T, Chen JN, Hynan LS, Cullum CM, Zhang R. One-year aerobic exercise altered cerebral vasomotor reactivity in mild cognitive impairment. J Appl Physiol (1985) 2021; 131:119-130. [PMID: 34013755 PMCID: PMC8325610 DOI: 10.1152/japplphysiol.00158.2021] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/10/2021] [Accepted: 05/10/2021] [Indexed: 01/21/2023] Open
Abstract
The purpose of this study was to test the hypothesis that changes in cerebral vasomotor reactivity (CVMR) after 1-yr aerobic exercise training (AET) are associated with cognitive performances in individuals with amnestic mild cognitive impairment (MCI). Seventy sedentary patients with amnestic MCI were randomized to 1-yr moderate-to-vigorous intensity AET or stretching and toning (SAT) interventions. Cerebral blood flow velocity (CBFV) with transcranial Doppler, mean arterial pressure (MAP) with finapres plethysmograph, and EtCO2 with capnography were measured during hyperventilation (hypocapnia) and a modified rebreathing protocol (hypercapnia) to assess CVMR. Cerebrovascular conductance index (CVCi) was calculated by CBFV/MAP, and CVMR by ΔCBFV/ΔEtCO2 and ΔCVCi/ΔEtCO2. Episodic memory and executive function were assessed using standard neuropsychological tests (CVLT-II and D-KEFS). Cardiorespiratory fitness was assessed by peak oxygen uptake (V̇o2peak). A total of 37 patients (19 in SAT and 18 in AET) completed 1-yr interventions and CVMR assessments. AET improved V̇o2peak, increased hypocapnic CVMR, but decreased hypercapnic CVMR. The effects of AET on cognitive performance were minimal when compared with SAT. Across both groups, there was a negative correlation between changes in hypocapnic and hypercapnic CVMRs in CBFV% and CVCi% (r = -0.741, r = -0.725, P < 0.001). Attenuated hypercapnic CVMR, but not increased hypocapnic CVMR, was associated with improved cognitive test scores in the AET group. In conclusion, 1-yr AET increased hypocapnic CVMR and attenuated hypercapnic CVMR which is associated cognitive performance in patients with amnestic MCI.NEW & NOTEWORTHY One-year moderate-to-vigorous intensity aerobic exercise training (AET) improved cardiorespiratory fitness (V̇o2peak), increased hypocapnic cerebral vasomotor reactivity (CVMR), whereas it decreased hypercapnic CVMR when compared with stretching and toning in patients with amnestic mild cognitive impairment (MCI). Furthermore, changes in hypercapnic CVMR with AET were correlated with improved memory and executive function. These findings indicate that AET has an impact on cerebrovascular function which may benefit cognitive performance in older adults who have high risk of Alzheimer's disease.
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Affiliation(s)
- Tsubasa Tomoto
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Takashi Tarumi
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas
- Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan
| | - Jason N Chen
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Linda S Hynan
- Department of Population and Data Sciences (Biostatistics), University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - C Munro Cullum
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Rong Zhang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
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31
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Slowed Temporal and Parietal Cerebrovascular Response in Patients with Alzheimer's Disease. Can J Neurol Sci 2021; 47:366-373. [PMID: 32051047 DOI: 10.1017/cjn.2020.30] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Recent investigations now suggest that cerebrovascular reactivity (CVR) is impaired in Alzheimer's disease (AD) and may underpin part of the disease's neurovascular component. However, our understanding of the relationship between the magnitude of CVR, the speed of cerebrovascular response, and the progression of AD is still limited. This is especially true in patients with mild cognitive impairment (MCI), which is recognized as an intermediate stage between normal aging and dementia. The purpose of this study was to investigate AD and MCI patients by mapping repeatable and accurate measures of cerebrovascular function, namely the magnitude and speed of cerebrovascular response (τ) to a vasoactive stimulus in key predilection sites for vascular dysfunction in AD. METHODS Thirty-three subjects (age range: 52-83 years, 20 males) were prospectively recruited. CVR and τ were assessed using blood oxygen level-dependent MRI during a standardized carbon dioxide stimulus. Temporal and parietal cortical regions of interest (ROIs) were generated from anatomical images using the FreeSurfer image analysis suite. RESULTS Of 33 subjects recruited, 3 individuals were excluded, leaving 30 subjects for analysis, consisting of 6 individuals with early AD, 11 individuals with MCI, and 13 older healthy controls (HCs). τ was found to be significantly higher in the AD group compared to the HC group in both the temporal (p = 0.03) and parietal cortex (p = 0.01) following a one-way ANCOVA correcting for age and microangiopathy scoring and a Bonferroni post-hoc correction. CONCLUSION The study findings suggest that AD is associated with a slowing of the cerebrovascular response in the temporal and parietal cortices.
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Lynch CE, Eisenbaum M, Algamal M, Balbi M, Ferguson S, Mouzon B, Saltiel N, Ojo J, Diaz-Arrastia R, Mullan M, Crawford F, Bachmeier C. Impairment of cerebrovascular reactivity in response to hypercapnic challenge in a mouse model of repetitive mild traumatic brain injury. J Cereb Blood Flow Metab 2021; 41:1362-1378. [PMID: 33050825 PMCID: PMC8142124 DOI: 10.1177/0271678x20954015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Incidences of repetitive mild TBI (r-mTBI), like those sustained by contact sports athletes and military personnel, are thought to be a risk factor for development of neurodegenerative disorders. Those suffering from chronic TBI-related illness demonstrate deficits in cerebrovascular reactivity (CVR), the ability of the cerebral vasculature to respond to a vasoactive stimulus. CVR is thus an important measure of traumatic cerebral vascular injury (TCVI), and a possible in vivo endophenotype of TBI-related neuropathogenesis. We combined laser speckle imaging of CVR in response to hypercapnic challenge with neurobehavioral assessment of learning and memory, to investigate if decreased cerebrovascular responsiveness underlies impaired cognitive function in our mouse model of chronic r-mTBI. We demonstrate a profile of blunted hypercapnia-evoked CVR in the cortices of r-mTBI mice like that of human TBI, alongside sustained memory and learning impairment, without biochemical or immunohistopathological signs of cerebral vessel laminar or endothelium constituent loss. Transient decreased expression of alpha smooth muscle actin and platelet-derived growth factor receptor β, indicative of TCVI, is obvious only at the time of the most pronounced CVR deficit. These findings implicate CVR as a valid preclinical measure of TCVI, perhaps useful for developing therapies targeting TCVI after recurrent mild head trauma.
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Affiliation(s)
- Cillian E Lynch
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK.,James A. Haley Veteran's Administration, Tampa, FL, USA.,Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Maxwell Eisenbaum
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK
| | - Moustafa Algamal
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK
| | - Matilde Balbi
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Scott Ferguson
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK
| | - Benoit Mouzon
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK.,James A. Haley Veteran's Administration, Tampa, FL, USA
| | | | - Joseph Ojo
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK.,James A. Haley Veteran's Administration, Tampa, FL, USA
| | - Ramon Diaz-Arrastia
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Mike Mullan
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK
| | - Fiona Crawford
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK.,James A. Haley Veteran's Administration, Tampa, FL, USA
| | - Corbin Bachmeier
- The Roskamp Institute, Sarasota, FL, USA.,Department of Life Sciences, The Open University, Milton Keynes, UK.,Bay Pines VA Healthcare System, Bay Pines, FL, USA
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Migdal KU, Robinson AT, Watso JC, Babcock MC, Lennon SL, Martens CR, Serrador JM, Farquhar WB. Ten days of high dietary sodium does not impair cerebral blood flow regulation in healthy adults. Auton Neurosci 2021; 234:102826. [PMID: 34058717 DOI: 10.1016/j.autneu.2021.102826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 03/19/2021] [Accepted: 05/14/2021] [Indexed: 10/21/2022]
Abstract
High dietary sodium impairs cerebral blood flow regulation in rodents and is associated with increased stroke risk in humans. However, the effects of multiple days of high dietary sodium on cerebral blood flow regulation in humans is unknown. Therefore, the purpose of this study was to determine whether ten days of high dietary sodium impairs cerebral blood flow regulation. Ten participants (3F/7M; age: 30 ± 10 years; blood pressure (BP): 113 ± 8/62 ± 9 mmHg) participated in this randomized, cross-over design study. Participants were placed on 10-day diets that included either low- (1000 mg/d), medium- (2300 mg/d) or high- (7000 mg/d) sodium separated by ≥four weeks. Urinary sodium excretion, beat-to-beat BP (finger photoplethysmography), middle cerebral artery velocity (transcranial Doppler), and end-tidal carbon dioxide (capnography) was measured. Dynamic cerebral autoregulation during a ten-minute baseline was calculated and cerebrovascular reactivity assessed by determining the percent change in middle cerebral artery blood flow velocity to hypercapnia (8% CO2, 21% oxygen, balance nitrogen) and hypocapnia (via mild hyperventilation). Urinary sodium excretion increased in a stepwise manner (ANOVA P = 0.001) from the low, to medium, to high condition. There were no differences in dynamic cerebral autoregulation between conditions. While there was a trend for a difference during cerebrovascular reactivity to hypercapnia (ANOVA P = 0.06), this trend was abolished when calculating cerebrovascular conductance (ANOVA: P = 0.28). There were no differences in cerebrovascular reactivity (ANOVA P = 0.57) or conductance (ANOVA: P = 0.73) during hypocapnia. These data suggest that ten days of a high sodium diet does not impair cerebral blood flow regulation in healthy adults.
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Affiliation(s)
- Kamila U Migdal
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, United States of America
| | - Austin T Robinson
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, United States of America; School of Kinesiology, Auburn University, Auburn, AL, United States of America
| | - Joseph C Watso
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, United States of America
| | - Matthew C Babcock
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, United States of America
| | - Shannon L Lennon
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, United States of America
| | - Christopher R Martens
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, United States of America
| | - Jorge M Serrador
- Department of Pharmacology, Physiology & Neuroscience, Rutgers University, Newark, NJ, United States of America
| | - William B Farquhar
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, DE, United States of America.
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34
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Suri S, Bulte D, Chiesa ST, Ebmeier KP, Jezzard P, Rieger SW, Pitt JE, Griffanti L, Okell TW, Craig M, Chappell MA, Blockley NP, Kivimäki M, Singh-Manoux A, Khir AW, Hughes AD, Deanfield JE, Jensen DEA, Green SF, Sigutova V, Jansen MG, Zsoldos E, Mackay CE. Study Protocol: The Heart and Brain Study. Front Physiol 2021; 12:643725. [PMID: 33868011 PMCID: PMC8046163 DOI: 10.3389/fphys.2021.643725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/03/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND It is well-established that what is good for the heart is good for the brain. Vascular factors such as hypertension, diabetes, and high cholesterol, and genetic factors such as the apolipoprotein E4 allele increase the risk of developing both cardiovascular disease and dementia. However, the mechanisms underlying the heart-brain association remain unclear. Recent evidence suggests that impairments in vascular phenotypes and cerebrovascular reactivity (CVR) may play an important role in cognitive decline. The Heart and Brain Study combines state-of-the-art vascular ultrasound, cerebrovascular magnetic resonance imaging (MRI) and cognitive testing in participants of the long-running Whitehall II Imaging cohort to examine these processes together. This paper describes the study protocol, data pre-processing and overarching objectives. METHODS AND DESIGN The 775 participants of the Whitehall II Imaging cohort, aged 65 years or older in 2019, have received clinical and vascular risk assessments at 5-year-intervals since 1985, as well as a 3T brain MRI scan and neuropsychological tests between 2012 and 2016 (Whitehall II Wave MRI-1). Approximately 25% of this cohort are selected for the Heart and Brain Study, which involves a single testing session at the University of Oxford (Wave MRI-2). Between 2019 and 2023, participants will undergo ultrasound scans of the ascending aorta and common carotid arteries, measures of central and peripheral blood pressure, and 3T MRI scans to measure CVR in response to 5% carbon dioxide in air, vessel-selective cerebral blood flow (CBF), and cerebrovascular lesions. The structural and diffusion MRI scans and neuropsychological battery conducted at Wave MRI-1 will also be repeated. Using this extensive life-course data, the Heart and Brain Study will examine how 30-year trajectories of vascular risk throughout midlife (40-70 years) affect vascular phenotypes, cerebrovascular health, longitudinal brain atrophy and cognitive decline at older ages. DISCUSSION The study will generate one of the most comprehensive datasets to examine the longitudinal determinants of the heart-brain association. It will evaluate novel physiological processes in order to describe the optimal window for managing vascular risk in order to delay cognitive decline. Ultimately, the Heart and Brain Study will inform strategies to identify at-risk individuals for targeted interventions to prevent or delay dementia.
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Affiliation(s)
- Sana Suri
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
| | - Daniel Bulte
- Oxford Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Scott T. Chiesa
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Klaus P. Ebmeier
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
| | - Peter Jezzard
- FMRIB Centre, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Sebastian W. Rieger
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
- FMRIB Centre, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Jemma E. Pitt
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
| | - Ludovica Griffanti
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
- FMRIB Centre, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
| | - Thomas W. Okell
- FMRIB Centre, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Martin Craig
- Radiological Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, United Kingdom
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
- Nottingham Biomedical Research Centre, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Michael A. Chappell
- Radiological Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, United Kingdom
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
- Nottingham Biomedical Research Centre, Queens Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | | | - Mika Kivimäki
- Department of Epidemiology and Public Health, University College London, London, United Kingdom
| | - Archana Singh-Manoux
- Inserm U1153, Epidemiology of Ageing and Neurodegenerative Diseases, Paris, France
| | - Ashraf W. Khir
- Mechanical Engineering, Brunel University London, Uxbridge, United Kingdom
| | - Alun D. Hughes
- MRC Unit for Lifelong Health and Ageing, Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - John E. Deanfield
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Daria E. A. Jensen
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
| | - Sebastian F. Green
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
| | - Veronika Sigutova
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
| | - Michelle G. Jansen
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Enikő Zsoldos
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
| | - Clare E. Mackay
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, United Kingdom
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Krishnamurthy V, Sprick JD, Krishnamurthy LC, Barter JD, Turabi A, Hajjar IM, Nocera JR. The Utility of Cerebrovascular Reactivity MRI in Brain Rehabilitation: A Mechanistic Perspective. Front Physiol 2021; 12:642850. [PMID: 33815146 PMCID: PMC8009989 DOI: 10.3389/fphys.2021.642850] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/22/2021] [Indexed: 01/06/2023] Open
Abstract
Cerebrovascular control and its integration with other physiological systems play a key role in the effective maintenance of homeostasis in brain functioning. Maintenance, restoration, and promotion of such a balance are one of the paramount goals of brain rehabilitation and intervention programs. Cerebrovascular reactivity (CVR), an index of cerebrovascular reserve, plays an important role in chemo-regulation of cerebral blood flow. Improved vascular reactivity and cerebral blood flow are important factors in brain rehabilitation to facilitate desired cognitive and functional outcomes. It is widely accepted that CVR is impaired in aging, hypertension, and cerebrovascular diseases and possibly in neurodegenerative syndromes. However, a multitude of physiological factors influence CVR, and thus a comprehensive understanding of underlying mechanisms are needed. We are currently underinformed on which rehabilitation method will improve CVR, and how this information can inform on a patient's prognosis and diagnosis. Implementation of targeted rehabilitation regimes would be the first step to elucidate whether such regimes can modulate CVR and in the process may assist in improving our understanding for the underlying vascular pathophysiology. As such, the high spatial resolution along with whole brain coverage offered by MRI has opened the door to exciting recent developments in CVR MRI. Yet, several challenges currently preclude its potential as an effective diagnostic and prognostic tool in treatment planning and guidance. Understanding these knowledge gaps will ultimately facilitate a deeper understanding for cerebrovascular physiology and its role in brain function and rehabilitation. Based on the lessons learned from our group's past and ongoing neurorehabilitation studies, we present a systematic review of physiological mechanisms that lead to impaired CVR in aging and disease, and how CVR imaging and its further development in the context of brain rehabilitation can add value to the clinical settings.
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Affiliation(s)
- Venkatagiri Krishnamurthy
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VAMC, Decatur, GA, United States
- Division of Geriatrics and Gerontology, Department of Medicine, Emory University, Atlanta, GA, United States
- Department of Neurology, Emory University, Atlanta, GA, United States
| | - Justin D. Sprick
- Division of Renal Medicine, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Lisa C. Krishnamurthy
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VAMC, Decatur, GA, United States
- Department of Physics & Astronomy, Georgia State University, Atlanta, GA, United States
| | - Jolie D. Barter
- Division of Geriatrics and Gerontology, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Aaminah Turabi
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VAMC, Decatur, GA, United States
- Department of Biology, Georgia State University, Atlanta, GA, United States
| | - Ihab M. Hajjar
- Department of Neurology, Emory University, Atlanta, GA, United States
| | - Joe R. Nocera
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VAMC, Decatur, GA, United States
- Department of Neurology, Emory University, Atlanta, GA, United States
- Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States
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36
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Early fMRI responses to somatosensory and optogenetic stimulation reflect neural information flow. Proc Natl Acad Sci U S A 2021; 118:2023265118. [PMID: 33836602 PMCID: PMC7980397 DOI: 10.1073/pnas.2023265118] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
fMRI has revolutionized how neuroscientists investigate human brain functions and networks. To further advance understanding of brain functions, identifying the direction of information flow, such as thalamocortical versus corticothalamic projections, is critical. Because the early hemodynamic response at microvessels near active neurons can be detected by ultrahigh field fMRI, we propose using the onset times of fMRI responses to discern the information flow. This approach was confirmed by observing the ultrahigh spatiotemporal resolution BOLD fMRI responses to bottom-up somatosensory stimulation and top-down optogenetic stimulation of the primary motor cortex in anesthetized mice. Because ultrahigh field MRI is increasingly available, ultrahigh spatiotemporal fMRI will significantly facilitate the investigation of functional circuits in humans. Blood oxygenation level–dependent (BOLD) functional magnetic resonance imaging (fMRI) has been widely used to localize brain functions. To further advance understanding of brain functions, it is critical to understand the direction of information flow, such as thalamocortical versus corticothalamic projections. For this work, we performed ultrahigh spatiotemporal resolution fMRI at 15.2 T of the mouse somatosensory network during forepaw somatosensory stimulation and optogenetic stimulation of the primary motor cortex (M1). Somatosensory stimulation induced the earliest BOLD response in the ventral posterolateral nucleus (VPL), followed by the primary somatosensory cortex (S1) and then M1 and posterior thalamic nucleus. Optogenetic stimulation of excitatory neurons in M1 induced the earliest BOLD response in M1, followed by S1 and then VPL. Within S1, the middle cortical layers responded to somatosensory stimulation earlier than the upper or lower layers, whereas the upper cortical layers responded earlier than the other two layers to optogenetic stimulation in M1. The order of early BOLD responses was consistent with the canonical understanding of somatosensory network connections and cannot be explained by regional variabilities in the hemodynamic response functions measured using hypercapnic stimulation. Our data demonstrate that early BOLD responses reflect the information flow in the mouse somatosensory network, suggesting that high-field fMRI can be used for systems-level network analyses.
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37
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Moia S, Termenon M, Uruñuela E, Chen G, Stickland RC, Bright MG, Caballero-Gaudes C. ICA-based denoising strategies in breath-hold induced cerebrovascular reactivity mapping with multi echo BOLD fMRI. Neuroimage 2021; 233:117914. [PMID: 33684602 PMCID: PMC8351526 DOI: 10.1016/j.neuroimage.2021.117914] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/25/2021] [Accepted: 02/22/2021] [Indexed: 12/19/2022] Open
Abstract
Performing a BOLD functional MRI (fMRI) acquisition during breath-hold (BH) tasks is a non-invasive, robust method to estimate cerebrovascular reactivity (CVR). However, movement and breathing-related artefacts caused by the BH can substantially hinder CVR estimates due to their high temporal collinearity with the effect of interest, and attention has to be paid when choosing which analysis model should be applied to the data. In this study, we evaluate the performance of multiple analysis strategies based on lagged general linear models applied on multi-echo BOLD fMRI data, acquired in ten subjects performing a BH task during ten sessions, to obtain subject-specific CVR and haemodynamic lag estimates. The evaluated approaches range from conventional regression models, i.e. including drifts and motion timecourses as nuisance regressors, applied on single-echo or optimally-combined data, to more complex models including regressors obtained from multi-echo independent component analysis with different grades of orthogonalization in order to preserve the effect of interest, i.e. the CVR. We compare these models in terms of their ability to make signal intensity changes independent from motion, as well as the reliability as measured by voxelwise intraclass correlation coefficients of both CVR and lag maps over time. Our results reveal that a conservative independent component analysis model applied on the optimally-combined multi-echo fMRI signal offers the largest reduction of motion-related effects in the signal, while yielding reliable CVR amplitude and lag estimates, although a conventional regression model applied on the optimally-combined data results in similar estimates. This work demonstrates the usefulness of multi-echo based fMRI acquisitions and independent component analysis denoising for precision mapping of CVR in single subjects based on BH paradigms, fostering its potential as a clinically-viable neuroimaging tool for individual patients. It also proves that the way in which data-driven regressors should be incorporated in the analysis model is not straight-forward due to their complex interaction with the BH-induced BOLD response.
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Affiliation(s)
- Stefano Moia
- Basque Center on Cognition, Brain and Language, Donostia, Spain; University of the Basque Country UPV/EHU, Donostia, Spain.
| | - Maite Termenon
- Basque Center on Cognition, Brain and Language, Donostia, Spain
| | - Eneko Uruñuela
- Basque Center on Cognition, Brain and Language, Donostia, Spain; University of the Basque Country UPV/EHU, Donostia, Spain
| | - Gang Chen
- Scientific and Statistical Computing Core, NIMH/NIH/HHS, Bethesda, MD, United States
| | - Rachael C Stickland
- Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Molly G Bright
- Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States; Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States
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38
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Altered cerebrovascular reactivity due to respiratory rate and breath holding: a BOLD-fMRI study on healthy adults. Brain Struct Funct 2021; 226:1229-1239. [PMID: 33598760 DOI: 10.1007/s00429-021-02236-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 02/05/2021] [Indexed: 01/22/2023]
Abstract
Cerebrovascular reactivity (CVR) is of great significance for the treatment and prevention of cerebrovascular diseases. CVR can be mapped using the blood oxygenation level-dependent (BOLD) signal of fMRI. Breath holding (BH) is a reliable method to produce the desired increase in arterial CO2, while its application in clinical research is limited due to subject's compliance and variability. BH task with variable respiratory rates could allow more flexibility in clinical populations. In this study, 50 healthy volunteers were scanned for end-inspiration BH tasks with three different respiration rates. For the three respiratory rates BH tasks, the CVR was estimated based on the BOLD signal and general linear model (GLM) separately. Specifically, the extra time delay was considered for the hemodynamic response function, and the optimal delay was estimated for each voxel. To measure CVR in grey matter, BOLD signals of end-inspiration BH were used as regressors in general linear models to quantify their impact on CVR. This was performed for regions and voxels. Systematic differences were observed between the three end-inspiratory breathing rates. The greatest increase in activation intensity was found in fast breathing followed by self-paced and slow breathing. We conclude that the BH task of variable respiratory rates allows for CVR measurement, making breath-holding challenges more flexible and appropriate for routine practice.
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Arslan GD, Olgun A, Ozcan D, Gökcal E, Guven D, Asil T. Assessment of Cerebral Vasomotor Reactivity in Patients With Primary Open-angle Glaucoma and Ocular Hypertension Using the Breath-Holding Index. J Glaucoma 2021; 30:157-163. [PMID: 33074963 DOI: 10.1097/ijg.0000000000001711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/03/2020] [Indexed: 11/26/2022]
Abstract
PRCIS Patients with ocular hypertension (OHT) do not show impaired cerebral vasodilation responses to hypercapnia but patients with primary open-angle glaucoma (POAG) do. Impaired vasoreactivity in patients with POAG may have neuronal or vascular origins and increase stroke risk. PURPOSE To investigate changes in cerebral blood flow and cerebral vasomotor reactivity using the breath-holding index in patients with POAG and OHT, to examine whether these parameters contribute to the risk of ischemic stroke. METHODS Thirty patients with POAG, 30 patients with OHT, and 30 age- and sex-matched healthy control subjects were included in this university hospital-based, cross-sectional, and observational study. Eyes with a greater degree of visual field loss and/or more severe optic disc damage were selected for the study in patients with POAG, whereas in patients with OHT and controls, the study eye was chosen randomly. The mean blood flow velocity and breath-holding index were measured in the middle cerebral artery ipsilaterally in patient and control groups, by using transcranial Doppler ultrasonography. RESULTS The mean blood flow velocity and breath-holding indexes were significantly lower in patients with POAG than in the control group (all P<0.05). In the OHT group, the mean blood flow velocity and breath-holding indexes were not different from those in the control group. CONCLUSIONS Patients with POAG have impaired vasodilation response to hypercapnia. Presumably, the neuronal changes and deterioration of the endothelium-mediated vasodilatation in patients with glaucoma may disrupt the regulation of arteries and potentially present functional insufficiency on vasoreactivity. Moreover, impaired cerebral vascular regulation may contribute to the increased risk of stroke in patients with POAG.
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Affiliation(s)
| | | | - Delil Ozcan
- Department of Ophthalmology, University of Health Sciences Şişli Hamidiye Etfal Training and Research Hospital
| | - Elif Gökcal
- Department of Neurology, Bezmialem Vakif University School of Medicine, Istanbul, Turkey
| | - Dilek Guven
- Department of Ophthalmology, University of Health Sciences Şişli Hamidiye Etfal Training and Research Hospital
| | - Talip Asil
- Department of Neurology, Bezmialem Vakif University School of Medicine, Istanbul, Turkey
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Sabbatinelli J, Ramini D, Giuliani A, Recchioni R, Spazzafumo L, Olivieri F. Connecting vascular aging and frailty in Alzheimer's disease. Mech Ageing Dev 2021; 195:111444. [PMID: 33539904 DOI: 10.1016/j.mad.2021.111444] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/05/2021] [Accepted: 01/26/2021] [Indexed: 12/15/2022]
Abstract
Aging plays an important role in the etiology of the most common age-related diseases (ARDs), including Alzheimer's disease (AD). The increasing number of AD patients and the lack of disease-modifying drugs warranted intensive research to tackle the pathophysiological mechanisms underpinning AD development. Vascular aging/dysfunction is a common feature of almost all ARDs, including cardiovascular (CV) diseases, diabetes and AD. To this regard, interventions aimed at modifying CV outcomes are under extensive investigation for their pleiotropic role in ameliorating and slowing down cognitive impairment in middle-life and elderly individuals. Evidence from observational and clinical studies confirm the notion that the earlier the interventions are conducted, the most favorable are the effects on cognitive function. Therefore, epidemiological research should focus on the early detection of deviations from a healthy cognitive aging trajectory, through the stratification of adult individuals according to the rate of aging. Here, we review the interplay between vascular and cognitive dysfunctions associated with aging, to disentangle the complex mechanisms underpinning the development and progression of neurodegenerative disorders, with a specific focus on AD.
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Affiliation(s)
- Jacopo Sabbatinelli
- Department of Clinical and Molecular Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - Deborah Ramini
- Department of Clinical and Molecular Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - Angelica Giuliani
- Department of Clinical and Molecular Sciences, Università Politecnica delle Marche, Ancona, Italy.
| | - Rina Recchioni
- Center of Clinical Pathology and Innovative Therapy, IRCCS INRCA, Ancona, Italy
| | - Liana Spazzafumo
- Epidemiologic Observatory, Regional Health Agency, Regione Marche, Ancona, Italy
| | - Fabiola Olivieri
- Department of Clinical and Molecular Sciences, Università Politecnica delle Marche, Ancona, Italy; Center of Clinical Pathology and Innovative Therapy, IRCCS INRCA, Ancona, Italy
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Hartman YAW, Tillmans LCM, Benschop DL, Hermans ANL, Nijssen KMR, Eijsvogels TMH, Willems PHGM, Tack CJ, Hopman MTE, Claassen JAHR, Thijssen DHJ. Long-Term and Acute Benefits of Reduced Sitting on Vascular Flow and Function. Med Sci Sports Exerc 2021; 53:341-350. [PMID: 32826636 DOI: 10.1249/mss.0000000000002462] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE Sedentary behavior increases the risk for cardiovascular and cerebrovascular disease. To understand potential benefits and underlying mechanisms, we examined the acute and long-term effect of reduced sitting intervention on vascular and cerebrovascular function. METHODS This prospective study included 24 individuals with increased cardiovascular risk (65 ± 5 yr, 29.8 ± 3.9 kg·m-2). Before and after 16-wk reduced sitting, using a mobile health device with vibrotactile feedback, we examined (i) vascular function (flow-mediated dilation [FMD]), (ii) cerebral blood flow velocity (CBFv, transcranial Doppler), and (iii) cerebrovascular function (cerebral autoregulation [CA] and cerebral vasomotor reactivity [CVMR]). To better understand potential underlying mechanisms, before and after intervention, we evaluated the effects of 3 h sitting with and without light-intensity physical activity breaks (every 30 min). RESULTS The first wave of participants showed no change in sedentary time (n = 9, 10.3 ± 0.5 to 10.2 ± 0.5 h·d-1, P = 0.87). Upon intervention optimization by participants' feedback, the subsequent participants (n = 15) decreased sedentary time (10.2 ± 0.4 to 9.2 ± 0.3 h·d-1, P < 0.01). This resulted in significant increases in FMD (3.1% ± 0.3% to 3.8% ± 0.4%, P = 0.02) and CBFv (48.4 ± 2.6 to 51.4. ±2.6 cm·s-1, P = 0.02), without altering CA or CVMR. Before and after the 16-wk intervention, 3-h exposure to uninterrupted sitting decreased FMD and CBFv, whereas physical activity breaks prevented a decrease (both P < 0.05). CA and CVMR did not change (P > 0.20). CONCLUSION Long-term reduction in sedentary behavior improves peripheral vascular function and cerebral blood flow and acutely prevents impaired vascular function and decreased cerebral blood flow. These results highlight the potential benefits of reducing sedentary behavior to acutely and chronically improve cardio- or cerebrovascular risk.
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Affiliation(s)
- Yvonne A W Hartman
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - Laura C M Tillmans
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - David L Benschop
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - Astrid N L Hermans
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - Kevin M R Nijssen
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - Peter H G M Willems
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - Cees J Tack
- Department of Internal Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - Maria T E Hopman
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
| | - Jurgen A H R Claassen
- Department of Geriatric Medicine, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, THE NETHERLANDS
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García-Carpintero S, Domínguez-Bértalo J, Pedrero-Prieto C, Frontiñán-Rubio J, Amo-Salas M, Durán-Prado M, García-Pérez E, Vaamonde J, Alcain FJ. Ubiquinol Supplementation Improves Gender-Dependent Cerebral Vasoreactivity and Ameliorates Chronic Inflammation and Endothelial Dysfunction in Patients with Mild Cognitive Impairment. Antioxidants (Basel) 2021; 10:143. [PMID: 33498250 PMCID: PMC7909244 DOI: 10.3390/antiox10020143] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/11/2021] [Accepted: 01/14/2021] [Indexed: 12/13/2022] Open
Abstract
Ubiquinol can protect endothelial cells from multiple mechanisms that cause endothelial damage and vascular dysfunction, thus contributing to dementia. A total of 69 participants diagnosed with mild cognitive impairment (MCI) received either 200 mg/day ubiquinol (Ub) or placebo for 1 year. Cognitive assessment of patients was performed at baseline and after 1 year of follow-up. Patients' cerebral vasoreactivity was examined using transcranial Doppler sonography, and levels of Ub and lipopolysaccharide (LPS) in plasma samples were quantified. Cell viability and necrotic cell death were determined using the microvascular endothelial cell line bEnd3. Coenzyme Q10 (CoQ) levels increased in patients supplemented for 1 year with ubiquinol versus baseline and the placebo group, although higher levels were observed in male patients. The higher cCoQ concentration in male patients improved cerebral vasoreactivity CRV and reduced inflammation, although the effect of Ub supplementation on neurological improvement was negligible in this study. Furthermore, plasma from Ub-supplemented patients improved the viability of endothelial cells, although only in T2DM and hypertensive patients. This suggests that ubiquinol supplementation could be recommended to reach a concentration of 5 μg/mL in plasma in MCI patients as a complement to conventional treatment.
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Affiliation(s)
- Sonia García-Carpintero
- Department of Medical Sciences, Faculty of Medicine, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (S.G.-C.); (C.P.-P.); (J.F.-R.)
- Oxidative Stress and Neurodegeneration Group, Regional Centre for Biomedical Research, University of Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Javier Domínguez-Bértalo
- Neurology Department, Virgen de Altagracia Hospital—Manzanares, SESCAM, 13002 Manzanares, Spain;
| | - Cristina Pedrero-Prieto
- Department of Medical Sciences, Faculty of Medicine, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (S.G.-C.); (C.P.-P.); (J.F.-R.)
- Oxidative Stress and Neurodegeneration Group, Regional Centre for Biomedical Research, University of Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Javier Frontiñán-Rubio
- Department of Medical Sciences, Faculty of Medicine, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (S.G.-C.); (C.P.-P.); (J.F.-R.)
- Oxidative Stress and Neurodegeneration Group, Regional Centre for Biomedical Research, University of Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Mariano Amo-Salas
- Department of Mathematics, Faculty of Medicine, University of Castilla-La Mancha, 13071 Ciudad Real, Spain;
| | - Mario Durán-Prado
- Department of Medical Sciences, Faculty of Medicine, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (S.G.-C.); (C.P.-P.); (J.F.-R.)
- Oxidative Stress and Neurodegeneration Group, Regional Centre for Biomedical Research, University of Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Eloy García-Pérez
- Neurology Department, General University Hospital—Ciudad Real, SESCAM, 13005 Ciudad Real, Spain;
| | - Julia Vaamonde
- Department of Medical Sciences, Faculty of Medicine, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (S.G.-C.); (C.P.-P.); (J.F.-R.)
- Neurology Department, General University Hospital—Ciudad Real, SESCAM, 13005 Ciudad Real, Spain;
| | - Francisco J. Alcain
- Department of Medical Sciences, Faculty of Medicine, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (S.G.-C.); (C.P.-P.); (J.F.-R.)
- Oxidative Stress and Neurodegeneration Group, Regional Centre for Biomedical Research, University of Castilla-La Mancha, 13071 Ciudad Real, Spain
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Steinman J, Sun HS, Feng ZP. Microvascular Alterations in Alzheimer's Disease. Front Cell Neurosci 2021; 14:618986. [PMID: 33536876 PMCID: PMC7849053 DOI: 10.3389/fncel.2020.618986] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/17/2020] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder associated with continual decline in cognition and ability to perform routine functions such as remembering familiar places or understanding speech. For decades, amyloid beta (Aβ) was viewed as the driver of AD, triggering neurodegenerative processes such as inflammation and formation of neurofibrillary tangles (NFTs). This approach has not yielded therapeutics that cure the disease or significant improvements in long-term cognition through removal of plaques and Aβ oligomers. Some researchers propose alternate mechanisms that drive AD or act in conjunction with amyloid to promote neurodegeneration. This review summarizes the status of AD research and examines research directions including and beyond Aβ, such as tau, inflammation, and protein clearance mechanisms. The effect of aging on microvasculature is highlighted, including its contribution to reduced blood flow that impairs cognition. Microvascular alterations observed in AD are outlined, emphasizing imaging studies of capillary malfunction. The review concludes with a discussion of two therapies to protect tissue without directly targeting Aβ for removal: (1) administration of growth factors to promote vascular recovery in AD; (2) inhibiting activity of a calcium-permeable ion channels to reduce microglial activation and restore cerebral vascular function.
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Affiliation(s)
- Joe Steinman
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Hong-Shuo Sun
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Zhong-Ping Feng
- Department of Physiology, University of Toronto, Toronto, ON, Canada
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Öztürk B, Eroğlu E, Özön A, Koç G, Karadaş Ö. The effects of melatonin treatment on headache and vasomotor reactivity in patients with chronic tension-type headache. NEUROL SCI NEUROPHYS 2021. [DOI: 10.4103/nsn.nsn_7_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Macias-Verde D, Lara PC, Burgos-Burgos J. Same pollution sources for climate change might be hyperactivating the NLRP3 inflammasome and exacerbating neuroinflammation and SARS mortality. Med Hypotheses 2021; 146:110396. [PMID: 33243665 PMCID: PMC7963803 DOI: 10.1016/j.mehy.2020.110396] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 11/06/2020] [Indexed: 12/17/2022]
Abstract
We have reviewed a considerable amount of recent scientific papers relating inflammation caused by air pollution with chronic and severe medical conditions. Furthermore, there are evidences relating organ inflammation caused by not only outdoor long-term but also short-term inhaled radioisotopes contained in high polluted air or in household natural radioactive background aerosols, in addition to SARS-COV-2 attached to bioaerosols, which are related with a worst evolution of severe acute respiratory syndrome patients. Reactive oxygen species (ROS) production induced by the interaction with environmental ionizing radiation contained in pollution is pointed out as a critical mechanism that predispose mainly to elder population, but not excluding young subjects, presenting previous chronic conditions of lung inflammation or neuroinflammation, which can lead to the most serious consequences.
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Affiliation(s)
- David Macias-Verde
- Oncology Department, Hospitales Universitarios San Roque, Las Palmas, GC, Spain.
| | - Pedro C Lara
- Oncology Department, Hospitales Universitarios San Roque, Las Palmas, GC, Spain; Universidad Fernando Pessoa Canarias, Las Palmas, GC, Spain; Instituto Canario de Investigación del Cáncer, Tenerife, Spain
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Sünnetçi E, Solmaz V, Erbaş O. Chronic Oxytocin treatment has long lasting therapeutic potential in a rat model of neonatal hypercapnic-hypoxia injury, through enhanced GABAergic signaling and by reducing hippocampal gliosis with its anti-inflammatory feature. Peptides 2021; 135:170398. [PMID: 33022295 DOI: 10.1016/j.peptides.2020.170398] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 12/31/2022]
Abstract
Previous studies have shown that, oxytocin has anticonvulsant and neuroprotective effects. One of the most important complications of Hypercapnic-hypoxia is drug resistance epilepsy. Effects of chronic intraperitoneal oxytocin treatment on gliosis, neuroinflammation and seizure activity was investigated in a model in which rats were exposed to hypoxia on postnatal day 1 and later challenged to the seizure-inducing pentylenetetrazol Forty pups were included in the study on their first day of birth. 16 pups were exposed to 100% CO2 for 5 minutes and other 16 pups for 10 minutes. The remaining 8 pups comprised the control group. Groups were classified according to oxytocin administration within the first 4 weeks. Pentylenetetrazol was administered 6 months after the oxytocin treatment. The Racine's Convulsion Scale and onset times of first myoclonic jerk (FMJ) were evaluated. To determine the mechanisms by which oxytocin exerted its effects on hypercapnic-anoxia exposed rats, we performed CA1 total neuron count & CA1 GFAP immunostaining, and measured brain levels of TNF-α and GAD-67. The Racine scale and TNF-α values were significantly lower in both groups that received oxytocin, while time-to-FMJ and GAD-67 level were significantly higher. The histopathological evaluations showed that oxytocin had significant ameliorative effects (especially regarding gliosis) on the hippocampus of hypoxic rats. Regarding the results of present study, it can be speculated that after acute hypercapnic-anoxia exposure, chronic Oxytocin treatment has long lasting therapeutic potential on rats, possibly by reducing the gliosis with its anti-inflammatory feature and by activating the GABA pathway.
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Affiliation(s)
- Eda Sünnetçi
- Istanbul Training and Education Hospital, Department of Pediatrics, Istanbul, Turkey
| | - Volkan Solmaz
- Memorial hizmet hospital, neurology clinic, Istanbul, Turkey.
| | - Oytun Erbaş
- Demiroğlu Bilim University Medical School, Department of Physiology, İstanbul, Turkey
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Bright MG, Whittaker JR, Driver ID, Murphy K. Vascular physiology drives functional brain networks. Neuroimage 2020; 217:116907. [PMID: 32387624 PMCID: PMC7339138 DOI: 10.1016/j.neuroimage.2020.116907] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 04/27/2020] [Accepted: 05/03/2020] [Indexed: 12/12/2022] Open
Abstract
We present the first evidence for vascular regulation driving fMRI signals in specific functional brain networks. Using concurrent neuronal and vascular stimuli, we collected 30 BOLD fMRI datasets in 10 healthy individuals: a working memory task, flashing checkerboard stimulus, and CO2 inhalation challenge were delivered in concurrent but orthogonal paradigms. The resulting imaging data were averaged together and decomposed using independent component analysis, and three "neuronal networks" were identified as demonstrating maximum temporal correlation with the neuronal stimulus paradigms: Default Mode Network, Task Positive Network, and Visual Network. For each of these, we observed a second network component with high spatial overlap. Using dual regression in the original 30 datasets, we extracted the time-series associated with these network pairs and calculated the percent of variance explained by the neuronal or vascular stimuli using a normalized R2 parameter. In each pairing, one network was dominated by the appropriate neuronal stimulus, and the other was dominated by the vascular stimulus as represented by the end-tidal CO2 time-series recorded in each scan. We acquired a second dataset in 8 of the original participants, where no CO2 challenge was delivered and CO2 levels fluctuated naturally with breathing variations. Although splitting of functional networks was not robust in these data, performing dual regression with the network maps from the original analysis in this new dataset successfully replicated our observations. Thus, in addition to responding to localized metabolic changes, the brain's vasculature may be regulated in a coordinated manner that mimics (and potentially supports) specific functional brain networks. Multi-modal imaging and advances in fMRI acquisition and analysis could facilitate further study of the dual nature of functional brain networks. It will be critical to understand network-specific vascular function, and the behavior of a coupled vascular-neural network, in future studies of brain pathology.
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Affiliation(s)
- Molly G Bright
- Department of Physical Therapy and Human Movement Science, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA; Department of Biomedical Engineering, McCormick School of Engineering and Applied Sciences, Northwestern University, Evanston, IL, 60201, USA.
| | - Joseph R Whittaker
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, United Kingdom
| | - Ian D Driver
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, CF10 3AT, United Kingdom
| | - Kevin Murphy
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, United Kingdom
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Taneja K, Liu P, Xu C, Turner M, Zhao Y, Abdelkarim D, Thomas BP, Rypma B, Lu H. Quantitative Cerebrovascular Reactivity in Normal Aging: Comparison Between Phase-Contrast and Arterial Spin Labeling MRI. Front Neurol 2020; 11:758. [PMID: 32849217 PMCID: PMC7411174 DOI: 10.3389/fneur.2020.00758] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/19/2020] [Indexed: 12/20/2022] Open
Abstract
Purpose: Cerebrovascular reactivity (CVR) is an index of the dilatory function of cerebral blood vessels and has shown great promise in the diagnosis of risk factors in cerebrovascular disease. Aging is one such risk factor; thus, it is important to characterize age-related differences in CVR. CVR can be measured by BOLD MRI but few studies have measured quantitative cerebral blood flow (CBF)-based CVR in the context of aging. This study aims to determine the age effect on CVR using two quantitative CBF techniques, phase-contrast (PC), and arterial spin labeling (ASL) MRI. Methods: In 49 participants (32 younger and 17 older), CVR was measured with PC, ASL, and BOLD MRI. These CVR methods were compared across young and older groups to determine their dependence on age. PC and ASL CVR were also studied for inter-correlation and mean differences. Gray and white matter CVR values were also studied. Results: PC CVR was higher in younger participants than older participants (by 17%, p = 0.046). However, there were no age differences in ASL or BOLD CVR. ASL CVR was significantly correlated with PC CVR (p = 0.042) and BOLD CVR (p = 0.016), but its values were underestimated compared to PC CVR (p = 0.045). ASL CVR map revealed no difference between gray matter and white matter tissue types, whereas gray matter was significantly higher than white matter in the BOLD CVR map. Conclusion: This study compared two quantitative CVR techniques in the context of brain aging and revealed that PC CVR is a more sensitive method for detection of age differences, despite the absence of spatial information. The ASL method showed a significant correlation with PC and BOLD, but it tends to underestimate CVR due to confounding factors associated with this technique. Importantly, our data suggest that there is not a difference in CBF-based CVR between the gray and white matter, in contrast to previous observation using BOLD MRI.
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Affiliation(s)
- Kamil Taneja
- The Russel H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Peiying Liu
- The Russel H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Cuimei Xu
- The Russel H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Monroe Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States
| | - Yuguang Zhao
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States
| | - Dema Abdelkarim
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States
| | - Binu P Thomas
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Hanzhang Lu
- The Russel H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States.,Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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49
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Ogoh S, Shibata S, Ito G, Miyamoto T. Dynamic characteristics of cerebrovascular reactivity or ventilatory response to change in carbon dioxide. Exp Physiol 2020; 105:1515-1523. [PMID: 32700812 DOI: 10.1113/ep088800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/21/2020] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? What are the dynamic characteristics of cerebrovascular carbon dioxide reactivity and the central respiratory chemoreflex? What is the main finding and its importance? The transfer function gain from the end-tidal partial pressure of carbon dioxide to cerebral blood flow or ventilation decreased in the high frequency range at rest and during exercise. These findings indicate that the dynamic characteristics of both systems were not constant in all frequency ranges, and this trend was not modified by exercise. ABSTRACT The purpose of this study was to examine the dynamic characteristics of cerebrovascular reactivity and ventilatory response to change in arterial CO2 in all frequency ranges at rest using frequency domain analysis, and also to examine whether this is modified by dynamic exercise as with the traditionally determined cerebrovascular CO2 reactivity. In nine healthy young subjects, at rest and during exercise (cycling exercise at constant predetermined work rate corresponding to a V ̇ O 2 level of 0.90 l min-1 ), the dynamic characteristics of cerebrovascular CO2 reactivity and the central respiratory chemoreflex were assessed by transfer function analysis using a binary white-noise sequence (0-7% inspired CO2 fraction) from the end-tidal partial pressure of CO2 ( P ETC O 2 ) to the mean middle cerebral artery mean blood velocity (MCA Vm ) or minute ventilation ( V ̇ E ), respectively. In the high frequency range, both transfer function gains decreased but, interestingly, the cut-off frequency in the transfer function gain from P ETC O 2 to MCA Vm response was higher than that from P ETC O 2 to V ̇ E response at rest (0.024 vs. 0.015 Hz) and during exercise (0.030 vs. 0.011 Hz), indicating that cerebrovascular CO2 reactivity or central respiratory chemoreflex was not constant in all frequency ranges, and this trend was not modified by exercise. These findings suggest that dynamic characteristics of the cerebrovascular CO2 reactivity or central chemoreflex need to be assessed to identify the whole system because the traditional method cannot identify the property of time response of these systems.
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Affiliation(s)
- Shigehiko Ogoh
- Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama, 350-8585, Japan
| | - Shigeki Shibata
- Department of Physical Therapy, Kyorin University, 5-4-1 Shimorenjaku, Mitaka, Tokyo, Tokyo, 181-8621, Japan
| | - Go Ito
- Department of Sport and Health Sciemce, Osaka Sangyo University, 3-1-1 Nakagaito, Osaka, Osaka, 574-8530, Japan
| | - Tadayoshi Miyamoto
- Department of Sport and Health Sciemce, Osaka Sangyo University, 3-1-1 Nakagaito, Osaka, Osaka, 574-8530, Japan
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Abstract
Purpose of Review Risks for developing cardiovascular disease and cognitive decline increase with age. In women, these risks may be influenced by pregnancy history. This review provides an integrated evaluation of associations of pregnancy history with hypertension, brain atrophy, and cognitive decline in postmenopausal women. Recent Findings Atrophy in the occipital lobes of the brain was evident in women who had current hypertension and a history of preeclampsia. Deficits in visual memory in women with a history of preeclampsia are consistent with these brain structural changes. The blood velocity response to chemical and sympathoexcitatory stimuli were altered in women with a history of preeclampsia linking impairments in cerebrovascular regulation to the structural and functional changes in the brain. Summary Having a history of preeclampsia should require close monitoring of blood pressure and initiation of anti-hypertensive treatment in perimenopausal women. Mechanisms by which preeclampsia affects cerebrovascular structure and function require additional study.
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Affiliation(s)
- Kathleen B Miller
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Virginia M Miller
- Department of Surgery, Mayo Clinic, Medical Sci Bldg 421, 200 First St SW, Rochester, MN, 55905, USA.
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Medical Sci Bldg 421, 200 First St SW, Rochester, MN, 55905, USA.
| | - Jill N Barnes
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, USA
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