1
|
Soleimanzad H, Montaner M, Ternier G, Lemitre M, Silvestre JS, Kassis N, Giacobini P, Magnan C, Pain F, Gurden H. Obesity in Midlife Hampers Resting and Sensory-Evoked Cerebral Blood Flow in Mice. Obesity (Silver Spring) 2021; 29:150-158. [PMID: 33174382 DOI: 10.1002/oby.23051] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/10/2020] [Accepted: 09/14/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE This study aimed to investigate the effects of a high-fat diet (HFD) and aging on resting and activity-dependent cerebral blood flow (CBF). METHODS To run a comparison between obese and age-matched control animals, 6-week-old mice were fed either with regular chow or an HFD for 3 months or 8 months. Glucose tolerance and insulin sensitivity were assessed for metabolic phenotyping. Resting and odor-evoked CBF at the microvascular scale in the olfactory bulb (OB) was investigated by multiexposure speckle imaging. Immunolabeling-enabled imaging of solvent-cleared organs was used to analyze vascular density. The ejection fraction was studied by using cardioechography. Olfactory sensitivity was tested by using a buried-food test. RESULTS Glucose intolerance and compromised odor-evoked CBF were observed in obese mice in the younger group. Prolonged HFD feeding triggered insulin resistance and stronger impairment in activity-dependent CBF. Aging had a specific negative impact on resting CBF. There was no decrease in vascular density in the OB of obese mice, although cardiac function was impaired at both ages. In addition, decreased olfactory sensitivity was observed only in the older, middle-aged obese mice. CONCLUSIONS OB microvasculature in obese mice showed a specific functional feature characterized by impaired sensory-evoked CBF and a specific deleterious effect of aging on resting CBF.
Collapse
Affiliation(s)
- Haleh Soleimanzad
- Université de Paris, Unit of Functional and Adaptive Biology (BFA), UMR 8251 CNRS, Paris, France
| | - Mireia Montaner
- Université de Paris, Unit of Functional and Adaptive Biology (BFA), UMR 8251 CNRS, Paris, France
| | - Gaëtan Ternier
- Université de Lille, INSERM, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille, France
| | - Mathilde Lemitre
- Université de Paris, Paris Cardiovascular Research Center (PARCC), INSERM, Paris, France
| | | | - Nadim Kassis
- Université de Paris, Unit of Functional and Adaptive Biology (BFA), UMR 8251 CNRS, Paris, France
| | - Paolo Giacobini
- Université de Lille, INSERM, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille, France
| | - Christophe Magnan
- Université de Paris, Unit of Functional and Adaptive Biology (BFA), UMR 8251 CNRS, Paris, France
| | - Frédéric Pain
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, Palaiseau, France
| | - Hirac Gurden
- Université de Paris, Unit of Functional and Adaptive Biology (BFA), UMR 8251 CNRS, Paris, France
| |
Collapse
|
2
|
Schager B, Brown CE. Susceptibility to capillary plugging can predict brain region specific vessel loss with aging. J Cereb Blood Flow Metab 2020; 40:2475-2490. [PMID: 31903837 PMCID: PMC7820682 DOI: 10.1177/0271678x19895245] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/28/2019] [Accepted: 11/19/2019] [Indexed: 12/13/2022]
Abstract
Vessel loss in the aging brain is commonly reported, yet important questions remain concerning whether there are regional vulnerabilities and what mechanisms could account for these regional differences, if they exist. Here we imaged and quantified vessel length, tortuosity and width in 15 brain regions in young adult and aged mice. Our data indicate that vessel loss was most pronounced in white matter followed by cortical, then subcortical grey matter regions, while some regions (visual cortex, amygdala, thalamus) showed no decline with aging. Regions supplied by the anterior cerebral artery were more vulnerable to loss than those supplied by middle or posterior cerebral arteries. Vessel width and tortuosity generally increased with age but neither reliably predicted regional vessel loss. Since capillaries are naturally prone to plugging and prolonged obstructions often lead to vessel pruning, we hypothesized that regional susceptibilities to plugging could help predict vessel loss. By mapping the distribution of microsphere-induced capillary obstructions, we discovered that regions with a higher density of persistent obstructions were more likely to show vessel loss with aging and vice versa. These findings indicate that age-related vessel loss is region specific and can be explained, at least partially, by regional susceptibilities to capillary plugging.
Collapse
Affiliation(s)
- Ben Schager
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Craig E Brown
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
3
|
Ma J, Ma Y, Shuaib A, Winship IR. Improved collateral flow and reduced damage after remote ischemic perconditioning during distal middle cerebral artery occlusion in aged rats. Sci Rep 2020; 10:12392. [PMID: 32709950 PMCID: PMC7381676 DOI: 10.1038/s41598-020-69122-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/07/2020] [Indexed: 02/05/2023] Open
Abstract
Circulation through cerebral collaterals can maintain tissue viability until reperfusion is achieved. However, collateral circulation is time limited, and failure of collaterals is accelerated in the aged. Remote ischemic perconditioning (RIPerC), which involves inducing a series of repetitive, transient peripheral cycles of ischemia and reperfusion at a site remote to the brain during cerebral ischemia, may be neuroprotective and can prevent collateral failure in young adult rats. Here, we demonstrate the efficacy of RIPerC to improve blood flow through collaterals in aged (16-18 months of age) Sprague Dawley rats during a distal middle cerebral artery occlusion. Laser speckle contrast imaging and two-photon laser scanning microscopy were used to directly measure flow through collateral connections to ischemic tissue. Consistent with studies in young adult rats, RIPerC enhanced collateral flow by preventing the stroke-induced narrowing of pial arterioles during ischemia. This improved flow was associated with reduced early ischemic damage in RIPerC treated aged rats relative to controls. Thus, RIPerC is an easily administered, non-invasive neuroprotective strategy that can improve penumbral blood flow via collaterals. Enhanced collateral flow supports further investigation as an adjuvant therapy to recanalization therapy and a protective treatment to maintain tissue viability prior to reperfusion.
Collapse
Affiliation(s)
- Junqiang Ma
- Neurochemical Research Unit, Department of Psychiatry, 12-127 Clinical Sciences Building, University of Alberta, Edmonton, AB, T6G 2R3, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- First Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong, China
| | - Yonglie Ma
- Neurochemical Research Unit, Department of Psychiatry, 12-127 Clinical Sciences Building, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Ashfaq Shuaib
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Division of Neurology, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ian R Winship
- Neurochemical Research Unit, Department of Psychiatry, 12-127 Clinical Sciences Building, University of Alberta, Edmonton, AB, T6G 2R3, Canada.
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
4
|
Ma J, Ma Y, Shuaib A, Winship IR. Impaired Collateral Flow in Pial Arterioles of Aged Rats During Ischemic Stroke. Transl Stroke Res 2020; 11:243-253. [PMID: 31203565 PMCID: PMC7067739 DOI: 10.1007/s12975-019-00710-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/02/2019] [Accepted: 06/05/2019] [Indexed: 02/05/2023]
Abstract
Cerebral collateral circulation and age are critical factors in determining outcome from acute ischemic stroke. Aging may lead to rarefaction of cerebral collaterals, and thereby accelerate ischemic injury by reducing penumbral blood flow. Dynamic changes in pial collaterals after onset of cerebral ischemia may vary with age but have not been extensively studied. Here, laser speckle contrast imaging (LSCI) and two-photon laser scanning microscopy (TPLSM) were combined to monitor cerebral pial collaterals between the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) in young adult and aged male Sprague Dawley rats during distal middle cerebral artery occlusion (dMCAo). Histological analysis showed that aged rats had significantly greater volumes of ischemic damage than young rats. LSCI showed that cerebral collateral perfusion declined over time after stroke in aged and young rats, and that this decline was significantly greater in aged rats. TPLSM demonstrated that pial arterioles narrowed faster after dMCAo in aged rats compared to young adult rats. Notably, while arteriole vessel narrowing was comparable 4.5 h after ischemic onset in aged and young adult rats, red blood cell velocity was stable in young adults but declined over time in aged rats. Overall, red blood cell flux through pial arterioles was significantly reduced at all time-points after 90 min post-dMCAo in aged rats relative to young adult rats. Thus, collateral failure is more severe in aged rats with significantly impaired pial collateral dynamics (reduced diameter, red blood cell velocity, and red blood cell flux) relative to young adult rats.
Collapse
Affiliation(s)
- Junqiang Ma
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, 12-127 Clinical Sciences Building, Edmonton, AB, T6G 2R3, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- First Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong, China
| | - Yonglie Ma
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, 12-127 Clinical Sciences Building, Edmonton, AB, T6G 2R3, Canada
| | - Ashfaq Shuaib
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Division of Neurology, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ian R Winship
- Neurochemical Research Unit, Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, 12-127 Clinical Sciences Building, Edmonton, AB, T6G 2R3, Canada.
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
5
|
Abstract
Aging is the progressive decline of physiological functions necessary for survival and reproduction. In gaining a better understanding of the inevitable aging process, the hope is to preserve, promote, or delay healthy aging through the treatment of common age-associated diseases. Although there are theories that try to explain the aging process, none of them seem to fully satisfy. Microcirculation describes blood flow through the capillaries in the circulatory system. The main functions of the microcirculation are the delivery of oxgen and nutrients and the removal of CO2, metabolic debris, and toxins. The microcirculatory impairment or dysfunction over time will result in the accumulation of toxic products and CO2 and loss of nutrition supplementation and O2 in corresponding tissue systems or internal organs, which eventually affect normal tissue and organ functions, leading to aging. Therefore, I propose a microcirculatory theory of aging: aging is the process of continuous impairment of microcirculation in the body.
Collapse
Affiliation(s)
- Kunlin Jin
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, TX 76107, USA
| |
Collapse
|
6
|
Wengler K, Bangiyev L, Canli T, Duong TQ, Schweitzer ME, He X. 3D MRI of whole-brain water permeability with intrinsic diffusivity encoding of arterial labeled spin (IDEALS). Neuroimage 2019; 189:401-414. [DOI: 10.1016/j.neuroimage.2019.01.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/11/2019] [Accepted: 01/13/2019] [Indexed: 12/11/2022] Open
|
7
|
Li Y, Choi WJ, Wei W, Song S, Zhang Q, Liu J, Wang RK. Aging-associated changes in cerebral vasculature and blood flow as determined by quantitative optical coherence tomography angiography. Neurobiol Aging 2018; 70:148-159. [PMID: 30007164 DOI: 10.1016/j.neurobiolaging.2018.06.017] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 06/14/2018] [Accepted: 06/14/2018] [Indexed: 01/29/2023]
Abstract
Normal aging is associated with significant alterations in brain's vascular structure and function, which can lead to compromised cerebral circulation and increased risk of neurodegeneration. The in vivo examination of cerebral blood flow (CBF), including capillary beds, in aging brains with sufficient spatial detail remains challenging with current imaging modalities. In the present study, we use 3-dimensional (3-D) quantitative optical coherence tomography angiography (OCTA) to examine characteristic differences of the cerebral vasculatures and hemodynamics at the somatosensory cortex between old (16 months old) and young mice (2 months old) in vivo. The quantitative metrics include cortical vascular morphology, CBF, and capillary flow velocity. We show that compared with young mice, the pial arterial tortuosity increases by 14%, the capillary vessel density decreases by 15%, and the CBF reduces by 33% in the old mice. Most importantly, changes in capillary velocity and heterogeneity with aging are quantified for the first time with sufficiently high statistical power between young and old populations, with a 21% (p < 0.05) increase in capillary mean velocity and 19% (p ≤ 0.05) increase in velocity heterogeneity in the latter. Our findings through noninvasive imaging are in line with previous studies of vascular structure modification with aging, with additional quantitative assessment in capillary velocity enabled by advanced OCTA algorithms on a single imaging platform. The results offer OCTA as a promising neuroimaging tool to study vascular aging, which may shed new light on the investigations of vascular factors contributing to the pathophysiology of age-related neurodegenerative disorders.
Collapse
Affiliation(s)
- Yuandong Li
- Department of Bioengineering, College of Engineering and School of Medicine, University of Washington, Seattle, WA, USA
| | - Woo June Choi
- Department of Bioengineering, College of Engineering and School of Medicine, University of Washington, Seattle, WA, USA; School of Electrical and Electronics Engineering, College of ICT Engineering, Chung-Ang University, Seoul, Korea
| | - Wei Wei
- Department of Bioengineering, College of Engineering and School of Medicine, University of Washington, Seattle, WA, USA
| | - Shaozhen Song
- Department of Bioengineering, College of Engineering and School of Medicine, University of Washington, Seattle, WA, USA
| | - Qinqin Zhang
- Department of Bioengineering, College of Engineering and School of Medicine, University of Washington, Seattle, WA, USA
| | - Jialing Liu
- Department of Neurological Surgery, University of California, San Francisco and SFVAMC, San Francisco, CA, USA
| | - Ruikang K Wang
- Department of Bioengineering, College of Engineering and School of Medicine, University of Washington, Seattle, WA, USA.
| |
Collapse
|
8
|
Moeini M, Lu X, Avti PK, Damseh R, Bélanger S, Picard F, Boas D, Kakkar A, Lesage F. Compromised microvascular oxygen delivery increases brain tissue vulnerability with age. Sci Rep 2018; 8:8219. [PMID: 29844478 PMCID: PMC5974237 DOI: 10.1038/s41598-018-26543-w] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/16/2018] [Indexed: 11/22/2022] Open
Abstract
Despite the possible role of impaired cerebral tissue oxygenation in age-related cognition decline, much is still unknown about the changes in brain tissue pO2 with age. Using a detailed investigation of the age-related changes in cerebral tissue oxygenation in the barrel cortex of healthy, awake aged mice, we demonstrate decreased arteriolar and tissue pO2 with age. These changes are exacerbated after middle-age. We further uncovered evidence of the presence of hypoxic micro-pockets in the cortex of awake old mice. Our data suggests that from young to middle-age, a well-regulated capillary oxygen supply maintains the oxygen availability in cerebral tissue, despite decreased tissue pO2 next to arterioles. After middle-age, due to decreased hematocrit, reduced capillary density and higher capillary transit time heterogeneity, the capillary network fails to compensate for larger decreases in arterial pO2. The substantial decrease in brain tissue pO2, and the presence of hypoxic micro-pockets after middle-age are of significant importance, as these factors may be related to cognitive decline in elderly people.
Collapse
Affiliation(s)
- Mohammad Moeini
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada.,Research Center of Montreal Heart Institute, Montréal, QC, Canada.,Department of Chemistry, McGill University, Montréal, QC, Canada
| | - Xuecong Lu
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada.,Research Center of Montreal Heart Institute, Montréal, QC, Canada
| | - Pramod K Avti
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada.,Research Center of Montreal Heart Institute, Montréal, QC, Canada.,Department of Biophysics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Rafat Damseh
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada
| | - Samuel Bélanger
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada.,Research Center of Montreal Heart Institute, Montréal, QC, Canada
| | - Frédéric Picard
- Centre de Recherche de l'Institut Universitaire de Cardiologie et Pneumologie de Québec (IUCPQ), Québec, QC, Canada
| | - David Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Biomedical Engineering Department, College of Engineering, Boston University, Boston, MA, USA
| | - Ashok Kakkar
- Department of Chemistry, McGill University, Montréal, QC, Canada
| | - Frédéric Lesage
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montréal, QC, Canada. .,Research Center of Montreal Heart Institute, Montréal, QC, Canada.
| |
Collapse
|
9
|
Xu X, Wang B, Ren C, Hu J, Greenberg DA, Chen T, Xie L, Jin K. Age-related Impairment of Vascular Structure and Functions. Aging Dis 2017; 8:590-610. [PMID: 28966804 PMCID: PMC5614324 DOI: 10.14336/ad.2017.0430] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 04/30/2017] [Indexed: 12/12/2022] Open
Abstract
Among age-related diseases, cardiovascular and cerebrovascular diseases are major causes of death. Vascular dysfunction is a key characteristic of these diseases wherein age is an independent and essential risk factor. The present work will review morphological alterations of aging vessels in-depth, which includes the discussion of age-related microvessel loss and changes to vasculature involving the capillary basement membrane, intima, media, and adventitia as well as the accompanying vascular dysfunctions arising from these alterations.
Collapse
Affiliation(s)
- Xianglai Xu
- 1Zhongshan Hospital, Fudan University, Shanghai 200032, China.,2Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, TX 76107, USA
| | - Brian Wang
- 2Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, TX 76107, USA
| | - Changhong Ren
- 2Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, TX 76107, USA.,4Institute of Hypoxia Medicine, Xuanwu Hospital, Capital Medical University. Beijing, China
| | - Jiangnan Hu
- 2Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, TX 76107, USA
| | | | - Tianxiang Chen
- 6Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Liping Xie
- 3Department of Urology, the First Affiliated Hospital, Zhejiang University, Zhejiang Province, China
| | - Kunlin Jin
- 2Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, TX 76107, USA
| |
Collapse
|
10
|
Lucke-Wold BP, Turner RC, Logsdon AF, Rosen CL, Qaiser R. Blast Scaling Parameters: Transitioning from Lung to Skull Base Metrics. JOURNAL OF SURGERY AND EMERGENCY MEDICINE 2017; 1. [PMID: 28386605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 09/28/2022]
Abstract
Neurotrauma from blast exposure is one of the single most characteristic injuries of modern warfare. Understanding blast traumatic brain injury is critical for developing new treatment options for warfighters and civilians exposed to improvised explosive devices. Unfortunately, the pre-clinical models that are widely utilized to investigate blast exposure are based on archaic lung based parameters developed in the early 20th century. Improvised explosive devices produce a different type of injury paradigm than the typical mortar explosion. Protective equipment for the chest cavity has also improved over the past 100 years. In order to improve treatments, it is imperative to develop models that are based more on skull-based parameters. In this mini-review, we discuss the important anatomical and biochemical features necessary to develop a skull-based model.
Collapse
Affiliation(s)
| | - Ryan C Turner
- Department of Neurosurgery, West Virginia University, Morgantown, WV, USA
| | | | - Charles L Rosen
- Department of Neurosurgery, West Virginia University, Morgantown, WV, USA
| | - Rabia Qaiser
- Department of Neurosurgery, West Virginia University, Morgantown, WV, USA
| |
Collapse
|
11
|
Effects of Vascular Peptide Bioregulator on the Density of Microvascular Network in the Brain Cortex of Aged Rats. Bull Exp Biol Med 2016; 161:300-3. [DOI: 10.1007/s10517-016-3400-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Indexed: 10/21/2022]
|
12
|
Exercise training could improve age-related changes in cerebral blood flow and capillary vascularity through the upregulation of VEGF and eNOS. BIOMED RESEARCH INTERNATIONAL 2014; 2014:230791. [PMID: 24822184 PMCID: PMC4005099 DOI: 10.1155/2014/230791] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 03/24/2014] [Indexed: 11/30/2022]
Abstract
This study aimed to investigate the effect of exercise training on age-induced microvascular alterations in the brain. Additionally, the association with the protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) was also assessed. Male Wistar rats were divided into four groups: sedentary-young (SE-Young, n = 5), sedentary aged (SE-Aged, n = 8), immersed-aged (IM-Aged, n = 5), and exercise trained-aged (ET-Aged, 60 minutes/day and 5 days/week for 8 weeks, n = 8) rats. The MAPs of all aged groups, SE-Aged, IM-Aged, and ET-Aged, were significantly higher than that of the SE-Young group. The regional cerebral blood flow (rCBF) in the SE-Aged and IM-Aged was significantly decreased as compared to SE-Young groups. However, rCBF of ET-Aged group was significantly higher than that in the IM-Aged group (P < 0.05). Moreover, the percentage of capillary vascularity (%CV) and the levels of VEGF and eNOS in the ET-Aged group were significantly increased compared to the IM-Aged group (P < 0.05). These results imply that exercise training could improve age-induced microvascular changes and hypoperfusion closely associated with the upregulation of VEGF and eNOS.
Collapse
|
13
|
The effects of short-term enriched environment on capillaries of the middle-aged rat cortex. Neurosci Lett 2011; 505:186-90. [DOI: 10.1016/j.neulet.2011.10.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 09/29/2011] [Accepted: 10/06/2011] [Indexed: 11/17/2022]
|
14
|
Brown WR, Thore CR. Review: cerebral microvascular pathology in ageing and neurodegeneration. Neuropathol Appl Neurobiol 2011; 37:56-74. [PMID: 20946471 DOI: 10.1111/j.1365-2990.2010.01139.x] [Citation(s) in RCA: 526] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This review of age-related brain microvascular pathologies focuses on topics studied by this laboratory, including anatomy of the blood supply, tortuous vessels, venous collagenosis, capillary remnants, vascular density and microembolic brain injury. Our studies feature thick sections, large blocks embedded in celloidin, and vascular staining by alkaline phosphatase. This permits study of the vascular network in three dimensions, and the differentiation of afferent from efferent vessels. Current evidence suggests that there is decreased vascular density in ageing, Alzheimer's disease and leukoaraiosis, and cerebrovascular dysfunction precedes and accompanies cognitive dysfunction and neurodegeneration. A decline in cerebrovascular angiogenesis may inhibit recovery from hypoxia-induced capillary loss. Cerebral blood flow is inhibited by tortuous arterioles and deposition of excessive collagen in veins and venules. Misery perfusion due to capillary loss appears to occur before cell loss in leukoaraiosis, and cerebral blood flow is also reduced in the normal-appearing white matter. Hypoperfusion occurs early in Alzheimer's disease, inducing white matter lesions and correlating with dementia. In vascular dementia, cholinergic reductions are correlated with cognitive impairment, and cholinesterase inhibitors have some benefit. Most lipid microemboli from cardiac surgery pass through the brain in a few days, but some remain for weeks. They can cause what appears to be a type of vascular dementia years after surgery. Donepezil has shown some benefit. Emboli, such as clots, cholesterol crystals and microspheres can be extruded through the walls of cerebral vessels, but there is no evidence yet that lipid emboli undergo such extravasation.
Collapse
Affiliation(s)
- W R Brown
- Department of Radiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina, USA.
| | | |
Collapse
|
15
|
Shao WH, Li C, Chen L, Qiu X, Zhang W, Huang CX, Xia L, Kong JM, Tang Y. Stereological Investigation of Age-Related Changes of the Capillaries in White Matter. Anat Rec (Hoboken) 2010; 293:1400-7. [DOI: 10.1002/ar.21184] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
16
|
Brown WR, Blair RM, Moody DM, Thore CR, Ahmed S, Robbins ME, Wheeler KT. Capillary loss precedes the cognitive impairment induced by fractionated whole-brain irradiation: a potential rat model of vascular dementia. J Neurol Sci 2007; 257:67-71. [PMID: 17316691 DOI: 10.1016/j.jns.2007.01.014] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Brain tumor patients who are long-term survivors after whole-brain irradiation (WBI) often suffer cognitive impairment, including dementia. Although the pathogenic mechanisms remain poorly understood, our studies suggest that radiation-induced cognitive impairment may be a form of vascular dementia. We used a fractionated dose of gamma-rays that is biologically similar to that given to brain tumor patients. The brains of adult rats were irradiated with 40 Gy, in eight 5 Gy fractions over 4 weeks. Cognitive function was assessed prior to WBI and up to 9 months post-irradiation using a partially-baited radial arm maze. A significant increase in working memory errors was found in the irradiated rats by two-way ANOVA (p=0.0042). The increased errors occurred primarily at 6 and 9 months (p < 0.05, student's t-test). Vessel density was quantified using a stereology method with computerized image processing and analysis. Vessel density was unchanged 24 h after the last dose, but significantly decreased (p=0.002), by approximately 30%, from 10 weeks to 52 weeks. Thus, cognitive impairment arose after brain capillary loss in irradiated rats that show no other gross brain pathology. Capillary loss may play an important role in radiation-induced dementia and this may be a model of vascular dementia.
Collapse
Affiliation(s)
- William R Brown
- Department of Radiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
| | | | | | | | | | | | | |
Collapse
|
17
|
Brown WR, Thore CR, Moody DM, Robbins ME, Wheeler KT. Vascular Damage after Fractionated Whole-Brain Irradiation in Rats. Radiat Res 2005; 164:662-8. [PMID: 16238444 DOI: 10.1667/rr3453.1] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Whole-brain irradiation of animals and humans has been reported to lead to late delayed structural (vascular damage, demyelination, white matter necrosis) and functional (cognitive impairment) alterations. However, most of the experimental data on late delayed radiation-induced brain injury have been generated with large single doses or short fractionation schemes that may provide a less accurate indication of the events that occur after clinical whole-brain radiotherapy. The pilot study reported here investigates cerebral vascular pathology in male Fischer 344 rats after whole-brain irradiation with a fractionated total dose of 137Cs gamma rays that is expected to be biologically similar to that given to brain tumor patients. The brains of young adult rats (4 months old) were irradiated with a total dose of 40 Gy, given as eight 5-Gy fractions twice per week for 4 weeks. Brain capillary and arteriole pathology was studied using an alkaline phosphatase enzyme histochemistry method; vessel density and length were quantified using a stereology method with computerized image processing and analysis. Vessel density and length were unchanged 24 h after the last dose, but at 10 weeks postirradiation, both were substantially decreased. After 20 weeks, the rate of decline in the vessel density and length in irradiated rats was similar to that in unirradiated age-matched controls. No gross gliosis or demyelination was observed 12 months postirradiation using conventional histopathology techniques. We suggest that the early (10-week) and persistent vascular damage that occurs after a prolonged whole-brain irradiation fractionation scheme may play an important role in the development of late delayed radiation-induced brain injury.
Collapse
Affiliation(s)
- William R Brown
- Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
| | | | | | | | | |
Collapse
|
18
|
Abstract
Quantitative morphology of the CNS has recently undergone major developments. In particular, several new approaches, known as design-based stereologic methods, have become available and have been successfully applied to neuromorphological research. However, much confusion and uncertainty remains about the meaning, implications, and advantages of these design-based stereologic methods. The objective of this review is to provide some clarification. It does not comprise a full description of all stereologic methods available. Rather, it is written by users for users, provides the reader with a guided tour through the relevant literature. It has been the experience of the authors that most neuroscientists potentially interested in design-based stereology need to analyze volumes of brain regions, numbers of cells (neurons, glial cells) within these brain regions, mean volumes (nuclear, perikaryal) of these cells, length densities of linear biological structures such as vessels and nerve fibers within brain regions, and the cytoarchitecture of brain regions (i.e. the spatial distribution of cells within a region of interest). Therefore, a comprehensive introduction to design-based stereologic methods for estimating these parameters is provided. It is demonstrated that results obtained with design-based stereology are representative for the entire brain region of interest, and are independent of the size, shape, spatial orientation, and spatial distribution of the cells to be investigated. Also, it is shown that bias (i.e. systematic error) in results obtained with design-based stereology can be limited to a minimum, and that it is possible to assess the variability of these results. These characteristics establish the advantages of design-based stereologic methods in quantitative neuromorphology.
Collapse
Affiliation(s)
- C Schmitz
- Department of Psychiatry and Neuropsychology, Division of Cellular Neuroscience, University of Maastricht, P.O. Box 616, NL-6200 MD Maastricht, Netherlands.
| | | |
Collapse
|
19
|
Alba C, Vidal L, Díaz F, Villena A, de Vargas IP. Ultrastructural and quantitative age-related changes in capillaries of the dorsal lateral geniculate nucleus. Brain Res Bull 2004; 64:145-53. [PMID: 15342102 DOI: 10.1016/j.brainresbull.2004.06.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Revised: 05/26/2004] [Accepted: 06/09/2004] [Indexed: 10/26/2022]
Abstract
An ultrastructural and quantitative study of age-related changes in the capillaries of the dorsal lateral geniculate nucleus was carried out using male Wistar rats aged 3, 24, and 28 months. The most important structural changes were found in the basal lamina: thickenings either homogeneously distributed or in specific points; spurs towards the astrocyte sheath; and osmiophilic membrane-like inclusions located within the basal lamina. Endothelial cells and pericytes showed an increase in inclusions and dense bodies in the cytoplasm. The quantitative study showed that the most pronounced alteration was the thickening of the basal lamina, which existed at 24 months. Later, at 28 months, thinning of the endothelial cells was observed together with an increase in mitochondria size and the number of pinocytic vesicles. These changes could be an endothelial cell response to compensate for the increasing transport difficulties caused by the thickening of the basal lamina. The progressive age-related changes observed in the structure of the capillaries might have an effect on the regulation of blood and brain tissue exchanges, and thus might contribute to the development of degenerative alterations in surrounding aging neurones.
Collapse
Affiliation(s)
- C Alba
- Department of Histology and Pathology, Faculty of Medicine, University of Málaga, Campus de Teatinos, 29071 Málaga, Spain.
| | | | | | | | | |
Collapse
|