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Stenroos P, Guillemain I, Tesler F, Montigon O, Collomb N, Stupar V, Destexhe A, Coizet V, David O, Barbier EL. EEG-fMRI in awake rat and whole-brain simulations show decreased brain responsiveness to sensory stimulations during absence seizures. eLife 2024; 12:RP90318. [PMID: 38976325 PMCID: PMC11230625 DOI: 10.7554/elife.90318] [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] [Indexed: 07/09/2024] Open
Abstract
In patients suffering absence epilepsy, recurring seizures can significantly decrease their quality of life and lead to yet untreatable comorbidities. Absence seizures are characterized by spike-and-wave discharges on the electroencephalogram associated with a transient alteration of consciousness. However, it is still unknown how the brain responds to external stimuli during and outside of seizures. This study aimed to investigate responsiveness to visual and somatosensory stimulation in Genetic Absence Epilepsy Rats from Strasbourg (GAERS), a well-established rat model for absence epilepsy. Animals were imaged under non-curarized awake state using a quiet, zero echo time, functional magnetic resonance imaging (fMRI) sequence. Sensory stimulations were applied during interictal and ictal periods. Whole-brain hemodynamic responses were compared between these two states. Additionally, a mean-field simulation model was used to explain the changes of neural responsiveness to visual stimulation between states. During a seizure, whole-brain responses to both sensory stimulations were suppressed and spatially hindered. In the cortex, hemodynamic responses were negatively polarized during seizures, despite the application of a stimulus. The mean-field simulation revealed restricted propagation of activity due to stimulation and agreed well with fMRI findings. Results suggest that sensory processing is hindered or even suppressed by the occurrence of an absence seizure, potentially contributing to decreased responsiveness during this absence epileptic process.
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Affiliation(s)
- Petteri Stenroos
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Isabelle Guillemain
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
| | - Federico Tesler
- Paris-Saclay University, CNRS, Institut des Neurosciences (NeuroPSI), France, Saclay, France
| | - Olivier Montigon
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
- University Grenoble Alpes, Inserm, US17, CNRS, UAR 3552, CHU Grenoble Alpes, IRMaGe, Grenoble, France
| | - Nora Collomb
- University Grenoble Alpes, Inserm, US17, CNRS, UAR 3552, CHU Grenoble Alpes, IRMaGe, Grenoble, France
| | - Vasile Stupar
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
- University Grenoble Alpes, Inserm, US17, CNRS, UAR 3552, CHU Grenoble Alpes, IRMaGe, Grenoble, France
| | - Alain Destexhe
- Paris-Saclay University, CNRS, Institut des Neurosciences (NeuroPSI), France, Saclay, France
| | - Veronique Coizet
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
| | - Olivier David
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
- Aix Marseille University, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Emmanuel L Barbier
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
- University Grenoble Alpes, Inserm, US17, CNRS, UAR 3552, CHU Grenoble Alpes, IRMaGe, Grenoble, France
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2
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Hays Weeks CC, Zlatar ZZ, Meloy MJ, Shin DD, Thomas L, Wierenga CE. APOE Genotype Modifies the Association of Fusiform Gyrus Cerebral Metabolic Rate of Oxygen Consumption and Object Naming Performance. J Alzheimers Dis 2023; 91:1371-1383. [PMID: 36641668 DOI: 10.3233/jad-220749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND The apolipoprotein E (APOE) ɛ4 allele confers risk for age and Alzheimer's disease related cognitive decline but the mechanistic link remains poorly understood. Blood oxygenation level dependent (BOLD) response in the fusiform gyrus (FG) during object naming appears greater among APOEɛ4 carriers even in the face of equivalent cognitive performance, suggesting neural compensation. However, BOLD is susceptible to known age and APOE-related vascular changes that could confound its interpretation. OBJECTIVE To address this limitation, we used calibrated fMRI during an object naming task and a hypercapnic challenge to obtain a more direct measure of neural function - percent change cerebral metabolic rate of oxygen consumption (%ΔCMRO2). METHODS Participants were 45 older adults without dementia (28 ɛ4-, 17 ɛ4+) between the ages of 65 and 85. We examined APOE-related differences in %ΔCMRO2 in the FG during object naming and the extent to which APOE modified associations between FG %ΔCMRO2 and object naming accuracy. Exploratory analyses also tested the hypothesis that %ΔCMRO2 is less susceptible to vascular compromise than are measures of %ΔCBF and %ΔBOLD. RESULTS We observed a modifying role of APOE on associations between FG %ΔCMRO2 and cognition, with ɛ4 carriers (but not non-carriers) demonstrating a positive association between right FG %ΔCMRO2 and object naming accuracy. CONCLUSION Results suggest that the relationship between neural function and cognition is altered among older adult APOEɛ4 carriers prior to the onset of dementia, implicating CMRO2 response as a potential mechanism to support cognition in APOE-related AD risk.
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Affiliation(s)
- Chelsea C Hays Weeks
- VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, UC San Diego, La Jolla, CA, USA
| | | | - M J Meloy
- VA San Diego Healthcare System, San Diego, CA, USA
| | | | - Liu Thomas
- Department of Radiology, UC San Diego, La Jolla, CA, USA
| | - Christina E Wierenga
- VA San Diego Healthcare System, San Diego, CA, USA.,Department of Psychiatry, UC San Diego, La Jolla, CA, USA
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3
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Vigilant Attention, Cerebral Blood Flow and Grey Matter Volume Change after 36 h of Acute Sleep Deprivation in Healthy Male Adults: A Pilot Study. Brain Sci 2022; 12:brainsci12111534. [DOI: 10.3390/brainsci12111534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
It is commonly believed that alertness and attention decrease after sleep deprivation (SD). However, there are not enough studies on the changes in psychomotor vigilance testing (PVT) during SD and the corresponding changes in brain function and brain structure after SD. Therefore, we recruited 30 healthy adult men to perform a 36 h acute SD experiment, including the measurement of five indicators of PVT every 2 h, and analysis of cerebral blood flow (CBF) and grey matter volume (GMV) changes, before and after SD by magnetic resonance imaging (MRI). The PVT measurement found that the mean reaction time (RT), fastest 10% RT, minor lapses, and false starts all increased progressively within 20 h of SD, except for major lapses. Subsequently, all indexes showed a significant lengthening or increasing trend, and the peak value was in the range of 24 h-32 h and decreased at 36 h, in which the number of major lapses returned to normal. MRI showed that CBF decreased in the left orbital part of the superior frontal gyrus, the left of the rolandic operculum, the left triangular part, and the right opercular part of the inferior frontal gyrus, and CBF increased in the left lingual gyrus and the right superior gyrus after 36 h SD. The left lingual gyrus was negatively correlated with the major lapses, and both the inferior frontal gyrus and the superior frontal gyrus were positively correlated with the false starts. Still, there was no significant change in GMV. Therefore, we believe that 36 h of acute SD causes alterations in brain function and reduces alert attention, whereas short-term acute SD does not cause changes in brain structure.
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4
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Wu S, Tyler LK, Henson RN, Rowe JB, Cam-CAN, Tsvetanov KA. Cerebral blood flow predicts multiple demand network activity and fluid intelligence across the adult lifespan. Neurobiol Aging 2022; 121:1-14. [PMID: 36306687 PMCID: PMC7613814 DOI: 10.1016/j.neurobiolaging.2022.09.006] [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: 11/19/2021] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 10/14/2022]
Abstract
The preservation of cognitive function in old age is a public health priority. Cerebral hypoperfusion is a hallmark of dementia but its impact on maintaining cognitive ability across the lifespan is less clear. We investigated the relationship between baseline cerebral blood flow (CBF) and blood oxygenation level-dependent (BOLD) response during a fluid reasoning task in a population-based adult lifespan cohort. As age differences in CBF could lead to non-neuronal contributions to the BOLD signal, we introduced commonality analysis to neuroimaging to dissociate performance-related CBF effects from the physiological confounding effects of CBF on the BOLD response. Accounting for CBF, we confirmed that performance- and age-related differences in BOLD responses in the multiple-demand network were implicated in fluid reasoning. Age differences in CBF explained not only performance-related BOLD responses but also performance-independent BOLD responses. Our results suggest that CBF is important for maintaining cognitive function, while its non-neuronal contributions to BOLD signals reflect an age-related confound. Maintaining perfusion into old age may serve to support brain function and preserve cognitive performance.
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Affiliation(s)
- Shuyi Wu
- Centre for Speech, Language and the Brain, Department of Psychology, University of Cambridge, Cambridge, UK,Department of Management, School of Business, Hong Kong Baptist University, Hong Kong, China
| | - Lorraine K. Tyler
- Centre for Speech, Language and the Brain, Department of Psychology, University of Cambridge, Cambridge, UK
| | - Richard N.A. Henson
- Medical Research Council Cognition and Brain Sciences Unit, Department of Psychiatry, Cambridge, UK
| | - James B. Rowe
- Medical Research Council Cognition and Brain Sciences Unit, Department of Psychiatry, Cambridge, UK,Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Cam-CAN
- Centre for Speech, Language and the Brain, Department of Psychology, University of Cambridge, Cambridge, UK,Medical Research Council Cognition and Brain Sciences Unit, Department of Psychiatry, Cambridge, UK
| | - Kamen A. Tsvetanov
- Centre for Speech, Language and the Brain, Department of Psychology, University of Cambridge, Cambridge, UK,Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Corresponding author (, +44 1223 766 556)
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5
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Yabluchanskiy A, Nyul-Toth A, Csiszar A, Gulej R, Saunders D, Towner R, Turner M, Zhao Y, Abdelkari D, Rypma B, Tarantini S. Age-related alterations in the cerebrovasculature affect neurovascular coupling and BOLD fMRI responses: Insights from animal models of aging. Psychophysiology 2021; 58:e13718. [PMID: 33141436 PMCID: PMC9166153 DOI: 10.1111/psyp.13718] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/10/2020] [Accepted: 09/28/2020] [Indexed: 12/11/2022]
Abstract
The present and future research efforts in cognitive neuroscience and psychophysiology rely on the measurement, understanding, and interpretation of blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to effectively investigate brain function. Aging and age-associated pathophysiological processes change the structural and functional integrity of the cerebrovasculature which can significantly alter how the BOLD signal is recorded and interpreted. In order to gain an improved understanding of the benefits, drawbacks, and methodological implications for BOLD fMRI in the context of cognitive neuroscience, it is crucial to understand the cellular and molecular mechanism of age-related vascular pathologies. This review discusses the multifaceted effects of aging and the contributions of age-related pathologies on structural and functional integrity of the cerebral microcirculation as they has been investigated in animal models of aging, including age-related alterations in neurovascular coupling responses, cellular and molecular mechanisms involved in microvascular damage, vascular rarefaction, blood-brain barrier disruption, senescence, humoral deficiencies as they relate to, and potentially introduce confounding factors in the interpretation of BOLD fMRI.
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Affiliation(s)
- Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Adam Nyul-Toth
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA,Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Rafal Gulej
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma, OK, USA
| | - Debra Saunders
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma, OK, USA
| | - Rheal Towner
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma, OK, USA
| | - Monroe Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
| | - Yuguang Zhao
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
| | - Dema Abdelkari
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA,International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary,Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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6
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Tsvetanov KA, Henson RNA, Jones PS, Mutsaerts H, Fuhrmann D, Tyler LK, Rowe JB. The effects of age on resting-state BOLD signal variability is explained by cardiovascular and cerebrovascular factors. Psychophysiology 2021; 58:e13714. [PMID: 33210312 PMCID: PMC8244027 DOI: 10.1111/psyp.13714] [Citation(s) in RCA: 37] [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: 09/23/2019] [Revised: 07/27/2020] [Accepted: 09/28/2020] [Indexed: 12/18/2022]
Abstract
Accurate identification of brain function is necessary to understand neurocognitive aging, and thereby promote health and well-being. Many studies of neurocognitive aging have investigated brain function with the blood-oxygen level-dependent (BOLD) signal measured by functional magnetic resonance imaging. However, the BOLD signal is a composite of neural and vascular signals, which are differentially affected by aging. It is, therefore, essential to distinguish the age effects on vascular versus neural function. The BOLD signal variability at rest (known as resting state fluctuation amplitude, RSFA), is a safe, scalable, and robust means to calibrate vascular responsivity, as an alternative to breath-holding and hypercapnia. However, the use of RSFA for normalization of BOLD imaging assumes that age differences in RSFA reflecting only vascular factors, rather than age-related differences in neural function (activity) or neuronal loss (atrophy). Previous studies indicate that two vascular factors, cardiovascular health (CVH) and cerebrovascular function, are insufficient when used alone to fully explain age-related differences in RSFA. It remains possible that their joint consideration is required to fully capture age differences in RSFA. We tested the hypothesis that RSFA no longer varies with age after adjusting for a combination of cardiovascular and cerebrovascular measures. We also tested the hypothesis that RSFA variation with age is not associated with atrophy. We used data from the population-based, lifespan Cam-CAN cohort. After controlling for cardiovascular and cerebrovascular estimates alone, the residual variance in RSFA across individuals was significantly associated with age. However, when controlling for both cardiovascular and cerebrovascular estimates, the variance in RSFA was no longer associated with age. Grey matter volumes did not explain age differences in RSFA, after controlling for CVH. The results were consistent between voxel-level analysis and independent component analysis. Our findings indicate that cardiovascular and cerebrovascular signals are together sufficient predictors of age differences in RSFA. We suggest that RSFA can be used to separate vascular from neuronal factors, to characterize neurocognitive aging. We discuss the implications and make recommendations for the use of RSFA in the research of aging.
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Affiliation(s)
- Kamen A. Tsvetanov
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
- Department of PsychologyCentre for Speech, Language and the BrainUniversity of CambridgeCambridgeUK
| | - Richard N. A. Henson
- Medical Research Council Cognition and Brain Sciences UnitCambridgeUK
- Department of PsychiatryUniversity of CambridgeCambridgeUK
| | - P. Simon Jones
- Department of PsychologyCentre for Speech, Language and the BrainUniversity of CambridgeCambridgeUK
| | - Henk Mutsaerts
- Department of Radiology and Nuclear MedicineAmsterdam University Medical CenterAmsterdamthe Netherlands
| | - Delia Fuhrmann
- Medical Research Council Cognition and Brain Sciences UnitCambridgeUK
| | - Lorraine K. Tyler
- Department of PsychologyCentre for Speech, Language and the BrainUniversity of CambridgeCambridgeUK
| | - Cam‐CAN
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
- Department of PsychologyCentre for Speech, Language and the BrainUniversity of CambridgeCambridgeUK
| | - James B. Rowe
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
- Medical Research Council Cognition and Brain Sciences UnitCambridgeUK
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7
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Zhao Y, Liu P, Turner MP, Abdelkarim D, Lu H, Rypma B. The neural-vascular basis of age-related processing speed decline. Psychophysiology 2021; 58:e13845. [PMID: 34115388 DOI: 10.1111/psyp.13845] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 12/12/2022]
Abstract
Most studies examining neurocognitive aging are based on the blood-oxygen level-dependent signal obtained during functional magnetic resonance imaging (fMRI). The physiological basis of this signal is neural-vascular coupling, the process by which neurons signal cerebrovasculature to dilate in response to an increase in active neural metabolism due to stimulation. These fMRI studies of aging rely on the hemodynamic equivalence assumption that this process is not disrupted by physiologic deterioration associated with aging. Studies of neural-vascular coupling challenge this assumption and show that neural-vascular coupling is closely related to cognition. In this review, we put forward a theory of processing speed decline in aging and how it is related to age-related neural-vascular coupling changes based on the results of studies elucidating the relationships between cognition, cerebrovascular dynamics, and aging.
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Affiliation(s)
- Yuguang Zhao
- School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, Richardson, TX, USA
| | - Peiying Liu
- School of Medicine, Department of Radiology, Johns Hopkins University, Baltimore, MD, USA
| | - Monroe P Turner
- School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, Richardson, TX, USA
| | - Dema Abdelkarim
- School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, Richardson, TX, USA
| | - Hanzhang Lu
- School of Medicine, Department of Radiology, Johns Hopkins University, Baltimore, MD, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, Center for Brain Health, University of Texas at Dallas, Richardson, TX, USA
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8
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Blood oxygen level dependent fMRI and perfusion MRI in the sheep brain. Brain Res 2021; 1760:147390. [PMID: 33631207 DOI: 10.1016/j.brainres.2021.147390] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 11/23/2022]
Abstract
The ovine model could be an effective translational model but remains underexplored. Here, Blood Oxygen Level dependent functional MRI during visual stimulation and resting-state perfusion MRI were explored. We aimed at investigating the impact of isoflurane anesthesia during visual stimulation and evaluate resting cerebral blood flow and cerebral blood volume parameters in the lamb and adult sheep brain. BOLD fMRI and perfusion MRI after a bolus of DOTAREM were conducted in 4 lambs and 6 adult ewes at 3 T. A visual stimulation paradigm was delivered during fMRI at increasing isoflurane doses (1-3%). Robust but weak BOLD responses (0.21 ± 0.08%) were found in the lateral geniculate nucleus (LGN) up to 3% isoflurane anaesthesia. No significant differences were found beween BOLD responses in the range 1 to 3% ISO (p > 0.05). However, LGN cluster size decreased and functional localization became less reliable at high ISO doses (2.5-3% ISO). BOLD responses were weaker in adult sheep than in lambs (4.6 ± 1.5 versus 13.6 ± 8.5; p = 0.08). Relative cerebral blood volumes (rCBV) and relative cerebral blood flows (rCBF) were significantly higher (p < 0.0001) in lambs than in adult sheep for both gray and white matter. The impact of volatile anesthesia was explored for the first time on BOLD responses demonstrating increased reliability of functional localization of brain activity at low doses. Perfusion MRI was conducted for the first time in both lambs and adult ewes. Assessment of baseline cerebrovascular values are of interest for future studies of brain diseases allowing an improved interpretation of BOLD responses.
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9
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Tyndall AV, Longman RS, Sajobi TT, Parboosingh JS, Drogos LL, Davenport MH, Eskes GA, Hogan DB, Hill MD, Poulin MJ. Genetic Risk, Vascular Function, and Subjective Cognitive Complaints Predict Objective Cognitive Function in Healthy Older Adults: Results From the Brain in Motion Study. Front Integr Neurosci 2020; 14:571683. [PMID: 33224030 PMCID: PMC7669615 DOI: 10.3389/fnint.2020.571683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/18/2020] [Indexed: 11/13/2022] Open
Abstract
Aging is associated with subjective memory complaints. Approximately half of those with subjective memory complaints have objective cognitive impairment. Previous studies have provided evidence of an association between genetic risk for Alzheimer’s disease (AD) and dementia progression. Also, aging is a significant risk factor for vascular pathology that may underlie at least some of the cognitive changes. This study investigates the relative contribution of subjective cognitive complaints (SCC), vascular function, and genetic risk for dementia in predicting objective cognitive performance. Multiple regression and relative importance analysis were used to investigate the relative contribution of vascular function, self-reported SCC, and dementia genetic risk, in predicting objective cognition in a sample of 238 healthy community-dwelling older adults. Age, sex, premorbid cognitive abilities, subjective verbal memory complaints, higher cerebrovascular blood flow during submaximal exercise, and certain dementia risk alleles were significant predictors of worse objective verbal memory performance (p < 0.001, R2 = 35.2–36.4%). Using relative importance analysis, subjective verbal memory complaints, and certain dementia risk alleles contributed more variance than cerebrovascular measures. These results suggest that age-related changes in memory in healthy older adults can be predicted by subjective memory complaints, genetic risk, and to a lesser extent, cerebrovascular function.
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Affiliation(s)
- Amanda V Tyndall
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - R Stewart Longman
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Psychology, University of Calgary, Calgary, AB, Canada.,Psychology Service, Foothills Medical Centre, Alberta Health Services, Calgary, AB, Canada
| | - Tolulope T Sajobi
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jillian S Parboosingh
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute for Child and Maternal Health, University of Calgary, Calgary, AB, Canada
| | - Lauren L Drogos
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Margie H Davenport
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Gail A Eskes
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Departments of Psychiatry, Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - David B Hogan
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Michael D Hill
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marc J Poulin
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
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10
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Krishnamurthy V, Krishnamurthy LC, Drucker JH, Kundu S, Ji B, Hortman K, Roberts SR, Mammino K, Tran SM, Gopinath K, McGregor KM, Rodriguez AD, Qiu D, Crosson B, Nocera JR. Correcting Task fMRI Signals for Variability in Baseline CBF Improves BOLD-Behavior Relationships: A Feasibility Study in an Aging Model. Front Neurosci 2020; 14:336. [PMID: 32425745 PMCID: PMC7205008 DOI: 10.3389/fnins.2020.00336] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 03/20/2020] [Indexed: 12/24/2022] Open
Abstract
Blood Oxygen Level Dependent (BOLD) functional MRI is a complex neurovascular signal whose magnitude depends on baseline physiological factors such as cerebral blood flow (CBF). Because baseline CBF varies across the brain and is altered with aging, the interpretation of stand-alone aging-related BOLD changes can be misleading. The primary objective of this study was to develop a methodology that combines task fMRI and arterial spin labeling (ASL) techniques to sensitize task-induced BOLD activity by covarying out the baseline physiology (i.e., CBF) in an aging model. We recruited 11 younger and 13 older healthy participants who underwent ASL and an overt language fMRI task (semantic category member generation). We measured in-scanner language performance to investigate the effect of BOLD sensitization on BOLD-behavior relationships. The results demonstrate that our correction approach is effective at enhancing the specificity and sensitivity of the BOLD signal in both groups. In addition, the correction strengthens the statistical association between task BOLD activity and behavioral performance. Although CBF has inherent age dependence, our results show that retaining the age factor within CBF aides in greater sensitization of task fMRI signals. From a cognitive standpoint, compared to young adults, the older participants showed a delayed domain-general language-related task activity possibly due to compromised vessel compliance. Further, assessment of functional evolution of corrected BOLD activity revealed biphasic BOLD dynamics in both groups where BOLD deactivation may reflect greater semantic demand or increased premium on domain general executive functioning in response to task difficulty. Although it was promising to note that the predictability of behavior using the proposed methodology outperforms other methodologies (i.e., no correction and normalization by division), and provides moderate stability and adequate power, further work with a larger cohort and other task designs is necessary to improve the stability of predicting associated behavior. In summary, we recommend correction of task fMRI signals by covarying out baseline CBF especially when comparing groups with different neurovascular properties. Given that ASL and BOLD fMRI are well established and widely employed techniques, our proposed multi-modal methodology can be readily implemented into data processing pipelines to obtain more accurate BOLD activation maps.
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Affiliation(s)
- Venkatagiri Krishnamurthy
- Department of Neurology, Emory University, Atlanta, GA, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States
| | - Lisa C Krishnamurthy
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States.,Department of Physics and Astronomy, Georgia State University, Atlanta, GA, United States
| | - Jonathan H Drucker
- Department of Neurology, Emory University, Atlanta, GA, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States
| | - Suprateek Kundu
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA, United States
| | - Bing Ji
- Department of Neurology, Emory University, Atlanta, GA, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States.,Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States
| | - Kyle Hortman
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States
| | - Simone R Roberts
- Department of Neurology, Emory University, Atlanta, GA, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States.,Department of Psychology, Georgia State University, Atlanta, GA, United States
| | - Kevin Mammino
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States
| | - Stella M Tran
- Department of Psychology, Georgia State University, Atlanta, GA, United States
| | - Kaundinya Gopinath
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States
| | - Keith M McGregor
- Department of Neurology, Emory University, Atlanta, GA, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States
| | - Amy D Rodriguez
- Department of Neurology, Emory University, Atlanta, GA, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States
| | - Deqiang Qiu
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States
| | - Bruce Crosson
- Department of Neurology, Emory University, Atlanta, GA, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States.,Department of Psychology, Georgia State University, Atlanta, GA, United States
| | - Joe R Nocera
- Department of Neurology, Emory University, Atlanta, GA, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center (VAMC), Decatur, GA, United States.,Division of Physical Therapy, School of Medicine, Emory University, Atlanta, GA, United States
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11
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Abdelkarim D, Zhao Y, Turner MP, Sivakolundu DK, Lu H, Rypma B. A neural-vascular complex of age-related changes in the human brain: Anatomy, physiology, and implications for neurocognitive aging. Neurosci Biobehav Rev 2019; 107:927-944. [DOI: 10.1016/j.neubiorev.2019.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 08/02/2019] [Accepted: 09/02/2019] [Indexed: 01/09/2023]
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12
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Subramaniapillai S, Rajagopal S, Elshiekh A, Pasvanis S, Ankudowich E, Rajah MN. Sex Differences in the Neural Correlates of Spatial Context Memory Decline in Healthy Aging. J Cogn Neurosci 2019; 31:1895-1916. [DOI: 10.1162/jocn_a_01455] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Aging is associated with episodic memory decline and alterations in memory-related brain function. However, it remains unclear if age-related memory decline is associated with similar patterns of brain aging in women and men. In the current task fMRI study, we tested the hypothesis that there are sex differences in the effect of age and memory performance on brain activity during episodic encoding and retrieval of face–location associations (spatial context memory). Forty-one women and 41 men between the ages of 21 and 76 years participated in this study. Between-group multivariate partial least squares analysis of the fMRI data was conducted to directly test for sex differences and similarities in age-related and performance-related patterns of brain activity. Our behavioral analysis indicated no significant sex differences in retrieval accuracy on the fMRI tasks. In relation to performance effects, we observed similarities and differences in how retrieval accuracy related to brain activity in women and men. Both sexes activated dorsal and lateral PFC, inferior parietal cortex, and left parahippocampal gyrus at encoding, and this supported subsequent memory performance. However, there were sex differences in retrieval activity in these same regions and in lateral occipital-temporal and ventrolateral PFC. In relation to age effects, we observed sex differences in the effect of age on memory-related activity within PFC, inferior parietal cortex, parahippocampal gyrus, and lateral occipital-temporal cortices. Overall, our findings suggest that the neural correlates of age-related spatial context memory decline differ in women compared with men.
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Affiliation(s)
| | | | | | | | | | - M. Natasha Rajah
- McGill University
- Brain Imaging Centre, Douglas Institute Research Centre, Verdun, QC, Canada
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13
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Thamm T, Guo J, Rosenberg J, Liang T, Marks MP, Christensen S, Do HM, Kemp SM, Adair E, Eyngorn I, Mlynash M, Jovin TG, Keogh BP, Chen HJ, Lansberg MG, Albers GW, Zaharchuk G. Contralateral Hemispheric Cerebral Blood Flow Measured With Arterial Spin Labeling Can Predict Outcome in Acute Stroke. Stroke 2019; 50:3408-3415. [PMID: 31619150 DOI: 10.1161/strokeaha.119.026499] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background and Purpose- Imaging is frequently used to select acute stroke patients for intra-arterial therapy. Quantitative cerebral blood flow can be measured noninvasively with arterial spin labeling magnetic resonance imaging. Cerebral blood flow levels in the contralateral (unaffected) hemisphere may affect capacity for collateral flow and patient outcome. The goal of this study was to determine whether higher contralateral cerebral blood flow (cCBF) in acute stroke identifies patients with better 90-day functional outcome. Methods- Patients were part of the prospective, multicenter iCAS study (Imaging Collaterals in Acute Stroke) between 2013 and 2017. Consecutive patients were enrolled after being diagnosed with anterior circulation acute ischemic stroke. Inclusion criteria were ischemic anterior circulation stroke, baseline National Institutes of Health Stroke Scale score ≥1, prestroke modified Rankin Scale score ≤2, onset-to-imaging time <24 hours, with imaging including diffusion-weighted imaging and arterial spin labeling. Patients were dichotomized into high and low cCBF groups based on median cCBF. Outcomes were assessed by day-1 and day-5 National Institutes of Health Stroke Scale; and day-30 and day-90 modified Rankin Scale. Multivariable logistic regression was used to test whether cCBF predicted good neurological outcome (modified Rankin Scale score, 0-2) at 90 days. Results- Seventy-seven patients (41 women) met the inclusion criteria with median (interquartile range) age of 66 (55-76) yrs, onset-to-imaging time of 4.8 (3.6-7.7) hours, and baseline National Institutes of Health Stroke Scale score of 13 (9-20). Median cCBF was 38.9 (31.2-44.5) mL per 100 g/min. Higher cCBF predicted good outcome at day 90 (odds ratio, 4.6 [95% CI, 1.4-14.7]; P=0.01), after controlling for baseline National Institutes of Health Stroke Scale, diffusion-weighted imaging lesion volume, and intra-arterial therapy. Conclusions- Higher quantitative cCBF at baseline is a significant predictor of good neurological outcome at day 90. cCBF levels may inform decisions regarding stroke triage, treatment of acute stroke, and general outcome prognosis. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT02225730.
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Affiliation(s)
- Thoralf Thamm
- From the Department of Radiology, Stanford University, CA (T.T., J.G., J.R., T.L., M.P.M., H.M.D., G.Z.)
- Center for Stroke Research Berlin, Charité-Universitätsmedizin Berlin, Germany (T.T.)
| | - Jia Guo
- From the Department of Radiology, Stanford University, CA (T.T., J.G., J.R., T.L., M.P.M., H.M.D., G.Z.)
- Department of Bioengineering, University of California Riverside, Riverside (J.G.)
| | - Jarrett Rosenberg
- From the Department of Radiology, Stanford University, CA (T.T., J.G., J.R., T.L., M.P.M., H.M.D., G.Z.)
| | - Tie Liang
- From the Department of Radiology, Stanford University, CA (T.T., J.G., J.R., T.L., M.P.M., H.M.D., G.Z.)
| | - Michael P Marks
- From the Department of Radiology, Stanford University, CA (T.T., J.G., J.R., T.L., M.P.M., H.M.D., G.Z.)
| | - Soren Christensen
- Department of Neurology and Neurological Sciences, Stanford Stroke Center, Stanford University, CA (S.C., S.M.K., E.A., I.E., M.M., M.G.L., G.W.A.)
| | - Huy M Do
- From the Department of Radiology, Stanford University, CA (T.T., J.G., J.R., T.L., M.P.M., H.M.D., G.Z.)
| | - Stephanie M Kemp
- Department of Neurology and Neurological Sciences, Stanford Stroke Center, Stanford University, CA (S.C., S.M.K., E.A., I.E., M.M., M.G.L., G.W.A.)
| | - Emma Adair
- Department of Neurology and Neurological Sciences, Stanford Stroke Center, Stanford University, CA (S.C., S.M.K., E.A., I.E., M.M., M.G.L., G.W.A.)
| | - Irina Eyngorn
- Department of Neurology and Neurological Sciences, Stanford Stroke Center, Stanford University, CA (S.C., S.M.K., E.A., I.E., M.M., M.G.L., G.W.A.)
| | - Michael Mlynash
- Department of Neurology and Neurological Sciences, Stanford Stroke Center, Stanford University, CA (S.C., S.M.K., E.A., I.E., M.M., M.G.L., G.W.A.)
| | - Tudor G Jovin
- Department of Neurology, Cooper Neurological Institute, Cooper University Hospital, Camden, NJ (T.G.J.)
| | - Bart P Keogh
- Department of Radiology, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, WA (B.P.K.)
| | - Hui J Chen
- Department of Radiology, Eden Medical Center, Castro Valley, CA (H.J.C.)
| | - Maarten G Lansberg
- Department of Neurology and Neurological Sciences, Stanford Stroke Center, Stanford University, CA (S.C., S.M.K., E.A., I.E., M.M., M.G.L., G.W.A.)
| | - Gregory W Albers
- Department of Neurology and Neurological Sciences, Stanford Stroke Center, Stanford University, CA (S.C., S.M.K., E.A., I.E., M.M., M.G.L., G.W.A.)
| | - Greg Zaharchuk
- From the Department of Radiology, Stanford University, CA (T.T., J.G., J.R., T.L., M.P.M., H.M.D., G.Z.)
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14
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Csipo T, Mukli P, Lipecz A, Tarantini S, Bahadli D, Abdulhussein O, Owens C, Kiss T, Balasubramanian P, Nyúl-Tóth Á, Hand RA, Yabluchanska V, Sorond FA, Csiszar A, Ungvari Z, Yabluchanskiy A. Assessment of age-related decline of neurovascular coupling responses by functional near-infrared spectroscopy (fNIRS) in humans. GeroScience 2019; 41:495-509. [PMID: 31676966 PMCID: PMC6885078 DOI: 10.1007/s11357-019-00122-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 10/11/2019] [Indexed: 12/31/2022] Open
Abstract
Preclinical studies provide strong evidence that age-related impairment of neurovascular coupling (NVC) plays a causal role in the pathogenesis of vascular cognitive impairment (VCI). NVC is a critical homeostatic mechanism in the brain, responsible for adjustment of local cerebral blood flow to the energetic needs of the active neuronal tissue. Recent progress in geroscience has led to the identification of critical cellular and molecular mechanisms involved in neurovascular aging, identifying these pathways as targets for intervention. In order to translate the preclinical findings to humans, there is a need to assess NVC in geriatric patients as an endpoint in clinical studies. Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging technique that enables the investigation of local changes in cerebral blood flow, quantifying task-related changes in oxygenated and deoxygenated hemoglobin concentrations. In the present overview, the basic principles of fNIRS are introduced and the application of this technique to assess NVC in older adults with implications for the design of studies on the mechanistic underpinnings of VCI is discussed.
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Affiliation(s)
- Tamas Csipo
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- Division of Clinical Physiology, Department of Cardiology / Kálmán Laki Doctoral School of Biomedical and Clinical Sciences, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Peter Mukli
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Agnes Lipecz
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- Department of Ophthalmology, Josa Andras Hospital, Nyiregyhaza, Hungary
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Dhay Bahadli
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
| | - Osamah Abdulhussein
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
| | - Cameron Owens
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
| | - Tamas Kiss
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Priya Balasubramanian
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
| | - Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Rachel A Hand
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
| | - Valeriya Yabluchanska
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- Bon Secours, St. Francis Family Medicine Center, Midlothian, VA, USA
| | - Farzaneh A Sorond
- Department of Neurology, Division of Stroke and Neurocritical Care, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA.
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15
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Hutter J, Harteveld AA, Jackson LH, Franklin S, Bos C, van Osch MJP, O'Muircheartaigh J, Ho A, Chappell L, Hajnal JV, Rutherford M, De Vita E. Perfusion and apparent oxygenation in the human placenta (PERFOX). Magn Reson Med 2019; 83:549-560. [PMID: 31433077 PMCID: PMC6825519 DOI: 10.1002/mrm.27950] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 07/18/2019] [Accepted: 07/25/2019] [Indexed: 02/05/2023]
Abstract
PURPOSE To study placental function-both perfusion and an oxygenation surrogate ( T 2 * )-simultaneously and quantitatively in-vivo. METHODS Fifteen pregnant women were scanned on a 3T MR scanner. For perfusion measurements, a velocity selective arterial spin labeling preparation module was placed before a multi-echo gradient echo EPI readout to integrate T 2 * and perfusion measurements in 1 joint perfusion-oxygenation (PERFOX) acquisition. Joint motion correction and quantification were performed to evaluate changes in T 2 * and perfusion over GA. RESULTS The optimized integrated PERFOX protocol and post-processing allowed successful visualization and quantification of perfusion and T 2 * in all subjects. Areas of high T 2 * and high perfusion appear to correspond to placental sub-units and show a systematic offset in location along the maternal-fetal axis. The areas of highest perfusion are consistently closer to the maternal basal plate and the areas of highest T 2 * closer to the fetal chorionic plate. Quantitative results show a strong negative correlation of gestational age with T 2 * and weak negative correlation with perfusion. CONCLUSIONS A strength of the joint sequence is that it provides truly simultaneous and co-registered estimates of local T 2 * and perfusion, however, to achieve this, the time per slice is prolonged compared to a perfusion only scan which can potentially limit coverage. The achieved interlocking can be particularly useful when quantifying transient physiological effects such as uterine contractions. PERFOX opens a new avenue to elucidate the relationship between maternal supply and oxygen uptake, both of which are central to placental function and dysfunction.
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Affiliation(s)
- Jana Hutter
- Centre for the Developing BrainKing's College LondonLondonUnited Kingdom
- School of Medical EngineeringKing's College LondonLondonUnited Kingdom
| | - Anita A. Harteveld
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Laurence H. Jackson
- Centre for the Developing BrainKing's College LondonLondonUnited Kingdom
- School of Medical EngineeringKing's College LondonLondonUnited Kingdom
| | - Suzanne Franklin
- C.J. Gorter Center for High Field MRIDepartment of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Clemens Bos
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Matthias J. P. van Osch
- C.J. Gorter Center for High Field MRIDepartment of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Jonathan O'Muircheartaigh
- Centre for the Developing BrainKing's College LondonLondonUnited Kingdom
- School of Medical EngineeringKing's College LondonLondonUnited Kingdom
| | - Alison Ho
- Academic Women's Health DepartmentKing's College LondonLondonUnited Kingdom
| | - Lucy Chappell
- Academic Women's Health DepartmentKing's College LondonLondonUnited Kingdom
| | - Joseph V. Hajnal
- Centre for the Developing BrainKing's College LondonLondonUnited Kingdom
- School of Medical EngineeringKing's College LondonLondonUnited Kingdom
| | - Mary Rutherford
- Centre for the Developing BrainKing's College LondonLondonUnited Kingdom
- School of Medical EngineeringKing's College LondonLondonUnited Kingdom
| | - Enrico De Vita
- School of Medical EngineeringKing's College LondonLondonUnited Kingdom
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16
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Optical measures of cerebral arterial stiffness are associated with white matter signal abnormalities and cognitive performance in normal aging. Neurobiol Aging 2019; 84:200-207. [PMID: 31500910 DOI: 10.1016/j.neurobiolaging.2019.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 05/29/2019] [Accepted: 08/05/2019] [Indexed: 12/25/2022]
Abstract
Decline in fluid abilities in normal aging is associated with increased white matter lesions, measured on T1-weighted images as white matter signal abnormalities (WMSAs). WMSAs are particularly evident in hypertensive older adults, suggesting vascular involvement. However, because hypertension is assessed systemically, the specific role of cerebral arterial stiffening in WMSAs has yet to be demonstrated. In 93 cognitively normal adults (aged 18-87 years), we used a novel method to measure cerebral arterial elasticity (pulse relaxation function [PReFx]) with diffuse optical tomography (pulse-DOT) and investigated its association with WMSAs, age, and cognition. PReFx was associated with WMSAs, with older adults with low PReFx showing the greatest WMSA burden. PReFx in brain regions perfused by the middle cerebral artery showed the largest associations with WMSAs and partially mediated the relationship between age and WMSAs. Finally, WMSAs partially mediated the relationship between PReFx and fluid but not crystallized abilities scores. Taken together, these findings suggest that loss of cerebral arterial elasticity is associated with cerebral white matter lesions and age-related cognitive decline.
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17
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Turner MP, Hubbard NA, Sivakolundu DK, Himes LM, Hutchison JL, Hart J, Spence JS, Frohman EM, Frohman TC, Okuda DT, Rypma B. Preserved canonicality of the BOLD hemodynamic response reflects healthy cognition: Insights into the healthy brain through the window of Multiple Sclerosis. Neuroimage 2019; 190:46-55. [PMID: 29454932 DOI: 10.1016/j.neuroimage.2017.12.081] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 12/18/2017] [Accepted: 12/22/2017] [Indexed: 10/18/2022] Open
Abstract
The hemodynamic response function (HRF), a model of brain blood-flow changes in response to neural activity, reflects communication between neurons and the vasculature that supplies these neurons in part by means of glial cell intermediaries (e.g., astrocytes). Intact neural-vascular communication might play a central role in optimal cognitive performance. This hypothesis can be tested by comparing healthy individuals to those with known white-matter damage and impaired performance, as seen in Multiple Sclerosis (MS). Glial cell intermediaries facilitate the ability of neurons to adequately convey metabolic needs to cerebral vasculature for sufficient oxygen and nutrient perfusion. In this study, we isolated measurements of the HRF that could quantify the extent to which white-matter affects neural-vascular coupling and cognitive performance. HRFs were modeled from multiple brain regions during multiple cognitive tasks using piecewise cubic spline functions, an approach that minimized assumptions regarding HRF shape that may not be valid for diseased populations, and were characterized using two shape metrics (peak amplitude and time-to-peak). Peak amplitude was reduced, and time-to-peak was longer, in MS patients relative to healthy controls. Faster time-to-peak was predicted by faster reaction time, suggesting an important role for vasodilatory speed in the physiology underlying processing speed. These results support the hypothesis that intact neural-glial-vascular communication underlies optimal neural and cognitive functioning.
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Affiliation(s)
- Monroe P Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Nicholas A Hubbard
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Dinesh K Sivakolundu
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Lyndahl M Himes
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Joanna L Hutchison
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - John Hart
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA; Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey S Spence
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Elliot M Frohman
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Teresa C Frohman
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Darin T Okuda
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, 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.
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18
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Courtney KE, Infante MA, Brown GG, Tapert SF, Simmons AN, Smith TL, Schuckit MA. The Relationship Between Regional Cerebral Blood Flow Estimates and Alcohol Problems at 5-Year Follow-Up: The Role of Level of Response. Alcohol Clin Exp Res 2019; 43:812-821. [PMID: 30924954 DOI: 10.1111/acer.13998] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/28/2019] [Indexed: 01/12/2023]
Abstract
BACKGROUND Acute alcohol consumption is associated with temporarily increased regional cerebral blood flow (CBF). The extent of this increase appears to be moderated by individual differences in the level of response (LR) to alcohol's subjective effects. The low LR phenotype is a known risk factor for the development of alcohol problems. This study investigates how the low LR phenotype relates to the relationship between alcohol-related changes in CBF and alcohol problems 5 years later. METHODS Young adults (ages 18 to 25) were selected based on their LR to alcohol and underwent a neuroimaging protocol including arterial spin labeling and functional scans. These participants were recontacted ~5 years later and assessed on alcohol outcomes. A final sample of 107 subjects (54 low and 53 high LR subjects) was included in the analyses. Whole-brain analysis revealed 5 clusters of significant alcohol-induced, versus placebo-induced, CBF changes that were consistent with a previous report. Peak alcohol-placebo CBF response was extracted from these regions and, along with the LR group, submitted to a hierarchical linear regression predicting alcohol problems. Analyses controlled for age, sex, and baseline alcohol problems. RESULTS In the regression analysis, greater alcohol-placebo CBF difference in the right middle/superior/inferior frontal gyri and bilateral anterior cingulate gyri clusters predicted greater future alcohol problems for the low LR group, whereas this relationship was not found to be significant in the high LR group. CONCLUSIONS This study demonstrates a clinically important relationship between CBF and future alcohol problems, particularly in individuals with a low LR phenotype. These initial results help to elucidate the neurobiological pathways involved in the development of alcohol use disorders for individuals with low LR.
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Affiliation(s)
- Kelly E Courtney
- Department of Psychiatry , University of California San Diego, La Jolla, California
| | | | - Gregory G Brown
- Department of Psychiatry , University of California San Diego, La Jolla, California.,Veteran's Affairs Healthcare System , San Diego, California
| | - Susan F Tapert
- Department of Psychiatry , University of California San Diego, La Jolla, California
| | - Alan N Simmons
- Department of Psychiatry , University of California San Diego, La Jolla, California.,Veteran's Affairs Healthcare System , San Diego, California
| | - Tom L Smith
- Department of Psychiatry , University of California San Diego, La Jolla, California
| | - Marc A Schuckit
- Department of Psychiatry , University of California San Diego, La Jolla, California
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19
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Wright ME, Wise RG. Can Blood Oxygenation Level Dependent Functional Magnetic Resonance Imaging Be Used Accurately to Compare Older and Younger Populations? A Mini Literature Review. Front Aging Neurosci 2018; 10:371. [PMID: 30483117 PMCID: PMC6243068 DOI: 10.3389/fnagi.2018.00371] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 10/25/2018] [Indexed: 11/17/2022] Open
Abstract
A wealth of research has investigated the aging brain using blood oxygenation level dependent functional MRI [Blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI)]. However, many studies do not consider the aging of the cerebrovascular system, which can influence the BOLD signal independently from neural activity, limiting what can be inferred when comparing age groups. Here, we discuss the ways in which the aging neurovascular system can impact BOLD fMRI, the consequences for age-group comparisons and possible strategies for mitigation. While BOLD fMRI is a valuable tool in this context, this review highlights the importance of consideration of vascular confounds.
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Affiliation(s)
- Melissa E Wright
- Cardiff University Brain Imaging Research Center, School of Psychology, Cardiff University, Cardiff, United Kingdom.,School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Richard G Wise
- Cardiff University Brain Imaging Research Center, School of Psychology, Cardiff University, Cardiff, United Kingdom
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20
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Chen JJ. Functional MRI of brain physiology in aging and neurodegenerative diseases. Neuroimage 2018; 187:209-225. [PMID: 29793062 DOI: 10.1016/j.neuroimage.2018.05.050] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 05/16/2018] [Accepted: 05/20/2018] [Indexed: 12/14/2022] Open
Abstract
Brain aging and associated neurodegeneration constitute a major societal challenge as well as one for the neuroimaging community. A full understanding of the physiological mechanisms underlying neurodegeneration still eludes medical researchers, fuelling the development of in vivo neuroimaging markers. Hence it is increasingly recognized that our understanding of neurodegenerative processes likely will depend upon the available information provided by imaging techniques. At the same time, the imaging techniques are often developed in response to the desire to observe certain physiological processes. In this context, functional MRI (fMRI), which has for decades provided information on neuronal activity, has evolved into a large family of techniques well suited for in vivo observations of brain physiology. Given the rapid technical advances in fMRI in recent years, this review aims to summarize the physiological basis of fMRI observations in healthy aging as well as in age-related neurodegeneration. This review focuses on in-vivo human brain imaging studies in this review and on disease features that can be imaged using fMRI methods. In addition to providing detailed literature summaries, this review also discusses future directions in the study of brain physiology using fMRI in the clinical setting.
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Affiliation(s)
- J Jean Chen
- Rotman Research Institute at Baycrest Centre, Canada; Department of Medical Biophysics, University of Toronto, Canada.
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21
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Cohen AD, Nencka AS, Wang Y. Multiband multi-echo simultaneous ASL/BOLD for task-induced functional MRI. PLoS One 2018; 13:e0190427. [PMID: 29389985 PMCID: PMC5794066 DOI: 10.1371/journal.pone.0190427] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 12/14/2017] [Indexed: 11/22/2022] Open
Abstract
Typical simultaneous blood oxygenation-level dependent (BOLD) and arterial spin labeling (ASL) sequences acquire two echoes, one perfusion-sensitive and one BOLD-sensitive. However, for ASL, spatial resolution and brain coverage are limited due to the T1 decay of the labeled blood. This study applies a sequence combining a multiband acquisition with four echoes for simultaneous BOLD and pseudo-continuous ASL (pCASL) echo planar imaging (MBME ASL/BOLD) for block-design task-fMRI. A multiband acceleration of four was employed to increase brain coverage and reduce slice-timing effects on the ASL signal. Multi-echo independent component analysis (MEICA) was implemented to automatically denoise the BOLD signal by regressing non-BOLD components. This technique led to increased temporal signal-to-noise ratio (tSNR) and BOLD sensitivity. The MEICA technique was also modified to denoise the ASL signal by regressing artifact and BOLD signals from the first echo time-series. The MBME ASL/BOLD sequence was applied to a finger-tapping task functional MRI (fMRI) experiment. Signal characteristics and activation were evaluated using single echo BOLD, combined ME BOLD, combined ME BOLD after MEICA denoising, perfusion-weighted (PW), and perfusion-weighted after MEICA denoising time-series. The PW data was extracted using both surround subtraction and high-pass filtering followed by demodulation. In addition, the CBF/BOLD response ratio and CBF/BOLD coupling were analyzed. Results showed that the MEICA denoising procedure significantly improved the BOLD signal, leading to increased BOLD sensitivity, tSNR, and activation statistics compared to conventional single echo BOLD data. At the same time, the denoised PW data showed increased tSNR and activation statistics compared to the non-denoised PW data. CBF/BOLD coupling was also increased using the denoised ASL and BOLD data. Our preliminary data suggest that the MBME ASL/BOLD sequence can be employed to collect whole-brain task-fMRI with improved data quality for both BOLD and PW time series, thus improving the results of block-design task fMRI.
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Affiliation(s)
- Alexander D Cohen
- Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Andrew S Nencka
- Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Yang Wang
- Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
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22
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Hubbard NA, Turner MP, Ouyang M, Himes L, Thomas BP, Hutchison JL, Faghihahmadabadi S, Davis SL, Strain JF, Spence J, Krawczyk DC, Huang H, Lu H, Hart J, Frohman TC, Frohman EM, Okuda DT, Rypma B. Calibrated imaging reveals altered grey matter metabolism related to white matter microstructure and symptom severity in multiple sclerosis. Hum Brain Mapp 2017; 38:5375-5390. [PMID: 28815879 DOI: 10.1002/hbm.23727] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 06/13/2017] [Accepted: 07/04/2017] [Indexed: 12/23/2022] Open
Abstract
Multiple sclerosis (MS) involves damage to white matter microstructures. This damage has been related to grey matter function as measured by standard, physiologically-nonspecific neuroimaging indices (i.e., blood-oxygen-level dependent signal [BOLD]). Here, we used calibrated functional magnetic resonance imaging and diffusion tensor imaging to examine the extent to which specific, evoked grey matter physiological processes were associated with white matter diffusion in MS. Evoked changes in BOLD, cerebral blood flow (CBF), and oxygen metabolism (CMRO2 ) were measured in visual cortex. Individual differences in the diffusion tensor measure, radial diffusivity, within occipital tracts were strongly associated with MS patients' BOLD and CMRO2 . However, these relationships were in opposite directions, complicating the interpretation of the relationship between BOLD and white matter microstructural damage in MS. CMRO2 was strongly associated with individual differences in patients' fatigue and neurological disability, suggesting that alterations to evoked oxygen metabolic processes may be taken as a marker for primary symptoms of MS. This work demonstrates the first application of calibrated and diffusion imaging together and details the first application of calibrated functional MRI in a neurological population. Results lend support for neuroenergetic hypotheses of MS pathophysiology and provide an initial demonstration of the utility of evoked oxygen metabolism signals for neurology research. Hum Brain Mapp 38:5375-5390, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Nicholas A Hubbard
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Monroe P Turner
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas
| | - Minhui Ouyang
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.,Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Lyndahl Himes
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas
| | - Binu P Thomas
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas.,Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Joanna L Hutchison
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas
| | | | - Scott L Davis
- Department of Applied Physiology and Wellness, Southern Methodist University, Dallas, Texas
| | - Jeremy F Strain
- Department of Neurology, Washington University in St. Louis, St. Louis, Missouri
| | - Jeffrey Spence
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas
| | - Daniel C Krawczyk
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Hao Huang
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.,Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Hanzhang Lu
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - John Hart
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Teresa C Frohman
- Department of Neurology, The University of Texas at Austin Dell Medical School, Austin, Texas
| | - Elliot M Frohman
- Department of Neurology, The University of Texas at Austin Dell Medical School, Austin, Texas
| | - Darin T Okuda
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas
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23
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Shigaeff N, Amaro E, Franco FGM, Jacinto AF, Chiochetta G, Cendoroglo MS, Citero VA. Functional magnetic resonance imaging response as an early biomarker of cognitive decline in elderly patients with metabolic syndrome. Arch Gerontol Geriatr 2017; 73:1-7. [PMID: 28711765 DOI: 10.1016/j.archger.2017.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 06/18/2017] [Accepted: 07/03/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVES We assessed whether potential changes in brain activation patterns of elderly individuals with metabolic syndrome (MetS) who were cognitively healthy (without mild cognitive impairment or dementia) were associated with cognitive decline in executive function in the short-term. METHOD We analyzed 43 individuals (23 MetS, 20 controls) using a global geriatric evaluation, a neuropsychological battery, and task-related (attention) fMRI exam. Correlation analysis between the fMRI signal at baseline and cognitive impairment after 1year was based on the voxel-based Pearson coefficient, corrected for multiple comparisons. RESULTS At baseline, MetS patients showed reduced brain response in frontal and parietal regions compared to controls. After one year, the MetS group also showed a decline in verbal fluency performance. fMRI response in the right dorsolateral prefrontal cortex and bilateral parietal lobes was negatively correlated with verbal fluency decline in the MetS group. DISCUSSION Our results provide an early biomarker of the possible development of cognitive impairment, particularly in the executive function, of elderly individuals suffering from MetS. These findings also point to an up or down regulation which could be interpreted as compensatory mechanism for possible brain tissue burden caused by MetS.
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Affiliation(s)
- Nadia Shigaeff
- Psychiatry Department, Escola Paulista de Medicina, Universidade Federal de São Paulo and Hospital Israelita Albert Einstein, Rua Borges Lagoa, 570, CEP:04038-030, São Paulo, SP, Brazil.
| | - Edson Amaro
- Hospital Israelita Albert Einstein, Avenida Albert Einstein, 627, Sao Paulo, Brazil.
| | - Fabio G M Franco
- Hospital Israelita Albert Einstein, Rua Madre Cabrini, 462, CEP:04020-001, São Paulo, SP, Brazil.
| | - Alessandro F Jacinto
- Psychiatry Department, Escola Paulista de Medicina, Universidade Federal de São, Paulo and Internal Medicine Department, Faculdade de Medicina de Botucatu, Universidade Estadual de Sao Paulo Julio de Mesquita Filho, Rua Borges Lagoa, 570, CEP:04038-030, São Paulo, SP, Brazil.
| | - Gabriela Chiochetta
- Psychiatry Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Borges Lagoa, 570, CEP:04038-030, São Paulo, SP, Brazil.
| | - Maysa S Cendoroglo
- Geriatric Division - Internal Medicine Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Francisco de Castro, 105, CEP:04020-050, São Paulo, SP, Brazil.
| | - Vanessa A Citero
- Psychiatry Department, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Borges Lagoa, 570, CEP:04038-030, São Paulo, SP, Brazil.
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24
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Liu X, Gerraty RT, Grinband J, Parker D, Razlighi QR. Brain atrophy can introduce age-related differences in BOLD response. Hum Brain Mapp 2017; 38:3402-3414. [PMID: 28397386 PMCID: PMC6866909 DOI: 10.1002/hbm.23597] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 03/10/2017] [Accepted: 03/22/2017] [Indexed: 11/08/2022] Open
Abstract
Use of functional magnetic resonance imaging (fMRI) in studies of aging is often hampered by uncertainty about age-related differences in the amplitude and timing of the blood oxygenation level dependent (BOLD) response (i.e., hemodynamic impulse response function (HRF)). Such uncertainty introduces a significant challenge in the interpretation of the fMRI results. Even though this issue has been extensively investigated in the field of neuroimaging, there is currently no consensus about the existence and potential sources of age-related hemodynamic alterations. Using an event-related fMRI experiment with two robust and well-studied stimuli (visual and auditory), we detected a significant age-related difference in the amplitude of response to auditory stimulus. Accounting for brain atrophy by circumventing spatial normalization and processing the data in subjects' native space eliminated these observed differences. In addition, we simulated fMRI data using age differences in brain morphology while controlling HRF shape. Analyzing these simulated fMRI data using standard image processing resulted in differences in HRF amplitude, which were eliminated when the data were analyzed in subjects' native space. Our results indicate that age-related atrophy introduces inaccuracy in co-registration to standard space, which subsequently appears as attenuation in BOLD response amplitude. Our finding could explain some of the existing contradictory reports regarding age-related differences in the fMRI BOLD responses. Hum Brain Mapp 38:3402-3414, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Xueqing Liu
- Biomedical Engineering DepartmentColumbia UniversityNew YorkNew YorkUnited States
| | - Raphael T. Gerraty
- Department of PsychologyColumbia UniversityNew YorkNew YorkUnited States
| | - Jack Grinband
- Department of RadiologyColumbia University Medical CenterNew YorkNew YorkUnited States
| | - David Parker
- Biomedical Engineering DepartmentColumbia UniversityNew YorkNew YorkUnited States
| | - Qolamreza R. Razlighi
- Biomedical Engineering DepartmentColumbia UniversityNew YorkNew YorkUnited States
- Department of NeurologyColumbia University Medical CenterNew YorkNew YorkUnited States
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25
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Haller S, Zaharchuk G, Thomas DL, Lovblad KO, Barkhof F, Golay X. Arterial Spin Labeling Perfusion of the Brain: Emerging Clinical Applications. Radiology 2017; 281:337-356. [PMID: 27755938 DOI: 10.1148/radiol.2016150789] [Citation(s) in RCA: 323] [Impact Index Per Article: 46.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Arterial spin labeling (ASL) is a magnetic resonance (MR) imaging technique used to assess cerebral blood flow noninvasively by magnetically labeling inflowing blood. In this article, the main labeling techniques, notably pulsed and pseudocontinuous ASL, as well as emerging clinical applications will be reviewed. In dementia, the pattern of hypoperfusion on ASL images closely matches the established patterns of hypometabolism on fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) images due to the close coupling of perfusion and metabolism in the brain. This suggests that ASL might be considered as an alternative for FDG, reserving PET to be used for the molecular disease-specific amyloid and tau tracers. In stroke, ASL can be used to assess perfusion alterations both in the acute and the chronic phase. In arteriovenous malformations and dural arteriovenous fistulas, ASL is very sensitive to detect even small degrees of shunting. In epilepsy, ASL can be used to assess the epileptogenic focus, both in peri- and interictal period. In neoplasms, ASL is of particular interest in cases in which gadolinium-based perfusion is contraindicated (eg, allergy, renal impairment) and holds promise in differentiating tumor progression from benign causes of enhancement. Finally, various neurologic and psychiatric diseases including mild traumatic brain injury or posttraumatic stress disorder display alterations on ASL images in the absence of visualized structural changes. In the final part, current limitations and future developments of ASL techniques to improve clinical applicability, such as multiple inversion time ASL sequences to assess alterations of transit time, reproducibility and quantification of cerebral blood flow, and to measure cerebrovascular reserve, will be reviewed. © RSNA, 2016 Online supplemental material is available for this article.
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Affiliation(s)
- Sven Haller
- From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.)
| | - Greg Zaharchuk
- From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.)
| | - David L Thomas
- From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.)
| | - Karl-Olof Lovblad
- From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.)
| | - Frederik Barkhof
- From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.)
| | - Xavier Golay
- From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.)
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26
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Leoni R, Oliveira I, Pontes-Neto O, Santos A, Leite J. Cerebral blood flow and vasoreactivity in aging: an arterial spin labeling study. Braz J Med Biol Res 2017; 50:e5670. [PMID: 28355354 PMCID: PMC5423749 DOI: 10.1590/1414-431x20175670] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 01/13/2017] [Indexed: 12/29/2022] Open
Abstract
Regional cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in young and elderly participants were assessed using pulsed arterial spin labeling (ASL) and blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) techniques in combination with inhalation of CO2. Pulsed ASL and BOLD-MRI were acquired in seventeen asymptomatic volunteers (10 young adults, age: 30±7 years; 7 elderly adults, age: 64±8 years) with no history of diabetes, hypertension, and neurological diseases. Data from one elderly participant was excluded due to the incorrigible head motion. Average baseline CBF in gray matter was significantly reduced in elderly (46±9 mL·100 g-1·min-1) compared to young adults (57±8 mL·100 g-1·min-1; P=0.02). Decreased pulsed ASL-CVR and BOLD-CVR in gray matter were also observed in elderly (2.12±1.30 and 0.13±0.06 %/mmHg, respectively) compared to young adults (3.28±1.43 and 0.28±0.11 %/mmHg, respectively; P<0.05), suggesting some degree of vascular impairment with aging. Moreover, age-related decrease in baseline CBF was observed in different brain regions (inferior, middle and superior frontal gyri; precentral and postcentral gyri; superior temporal gyrus; cingulate gyri; insula, putamen, caudate, and supramarginal gyrus). In conclusion, CBF and CVR were successfully investigated using a protocol that causes minimal or no discomfort for the participants. Age-related decreases in baseline CBF and CVR were observed in the cerebral cortex, which may be related to the vulnerability for neurological disorders in aging.
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Affiliation(s)
- R.F. Leoni
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - I.A.F. Oliveira
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - O.M. Pontes-Neto
- Departamento de Neurociências e Ciências do Comportamento, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - A.C. Santos
- Divisão de Radiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | - J.P. Leite
- Departamento de Neurociências e Ciências do Comportamento, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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27
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Optimizing fMRI preprocessing pipelines for block-design tasks as a function of age. Neuroimage 2017; 154:240-254. [PMID: 28216431 DOI: 10.1016/j.neuroimage.2017.02.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 01/04/2017] [Accepted: 02/10/2017] [Indexed: 11/21/2022] Open
Abstract
Functional Magnetic Resonance Imaging (fMRI) is a powerful neuroimaging tool, which is often hampered by significant noise confounds. There is evidence that our ability to detect activations in task fMRI is highly dependent on the preprocessing steps used to control noise and artifact. However, the vast majority of studies examining preprocessing pipelines in fMRI have focused on young adults. Given the widespread use of fMRI for characterizing the neurobiology of aging, it is critical to examine how the impact of preprocessing choices varies as a function of age. In this study, we employ the NPAIRS cross-validation framework, which optimizes pipelines based on metrics of prediction accuracy (P) and spatial reproducibility (R), to compare the effects of pipeline optimization between young (21-33 years) and older (61-82 years) cohorts, for three different block-design contrasts. Motion is shown to be a greater issue in the older cohort, and we introduce new statistical approaches to control for potential biases due to head motion during pipeline optimization. In comparison, data-driven methods of physiological noise correction show comparable benefits for both young and old cohorts. Using our optimization framework, we demonstrate that the optimal pipelines tend to be highly similar across age cohorts. In addition, there is a comparable, significant benefit of pipeline optimization across age cohorts, for (P, R) metrics and independent validation measures of activation overlap (both between-subject, within-session and within-subject, between-session). The choice of task contrast consistently shows a greater impact than the age cohort, for (P, R) metrics and activation overlap. Finally, adaptive pipeline optimization per task run shows improved sensitivity to age-related changes in brain activity, particularly for weaker, more complex cognitive contrasts. The current study provides the first detailed examination of preprocessing pipelines across age cohorts, demonstrating a significant benefit of adaptive pipeline optimization across age groups.
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28
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Sokolova IB, Sergeev IV, Fedotova OR, Melnikova NN, Dvoretsky DP. Age-related changes in microcirculation in the cortex of hypertonic rats. ADVANCES IN GERONTOLOGY 2017. [DOI: 10.1134/s2079057017010143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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29
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Luft CDB, Baker R, Goldstone A, Zhang Y, Kourtzi Z. Learning Temporal Statistics for Sensory Predictions in Aging. J Cogn Neurosci 2016; 28:418-32. [DOI: 10.1162/jocn_a_00907] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Abstract
Predicting future events based on previous knowledge about the environment is critical for successful everyday interactions. Here, we ask which brain regions support our ability to predict the future based on implicit knowledge about the past in young and older age. Combining behavioral and fMRI measurements, we test whether training on structured temporal sequences improves the ability to predict upcoming sensory events; we then compare brain regions involved in learning predictive structures between young and older adults. Our behavioral results demonstrate that exposure to temporal sequences without feedback facilitates the ability of young and older adults to predict the orientation of an upcoming stimulus. Our fMRI results provide evidence for the involvement of corticostriatal regions in learning predictive structures in both young and older learners. In particular, we showed learning-dependent fMRI responses for structured sequences in frontoparietal regions and the striatum (putamen) for young adults. However, for older adults, learning-dependent activations were observed mainly in subcortical (putamen, thalamus) regions but were weaker in frontoparietal regions. Significant correlations of learning-dependent behavioral and fMRI changes in these regions suggest a strong link between brain activations and behavioral improvement rather than general overactivation. Thus, our findings suggest that predicting future events based on knowledge of temporal statistics engages brain regions involved in implicit learning in both young and older adults.
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Hays CC, Zlatar ZZ, Wierenga CE. The Utility of Cerebral Blood Flow as a Biomarker of Preclinical Alzheimer's Disease. Cell Mol Neurobiol 2016; 36:167-79. [PMID: 26898552 DOI: 10.1007/s10571-015-0261-z] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/25/2015] [Indexed: 12/20/2022]
Abstract
There is accumulating evidence suggesting that changes in brain perfusion are present long before the clinical symptoms of Alzheimer's disease (AD), perhaps even before amyloid-β accumulation or brain atrophy. This evidence, consistent with the vascular hypothesis of AD, implicates cerebral blood flow (CBF) in the pathogenesis of AD and suggests its utility as a biomarker of preclinical AD. The extended preclinical phase of AD holds particular significance for disease modification, as treatment would likely be most effective in this early asymptomatic stage of disease. This highlights the importance of identifying reliable and accurate biomarkers of AD that can differentiate normal aging from preclinical AD prior to clinical symptom manifestation. Cerebral perfusion, as measured by arterial spin labeling magnetic resonance imaging (ASL-MRI), has been shown to distinguish between normal controls and adults with AD. In addition to demonstrating diagnostic utility, CBF has shown usefulness as a tool for identifying those who are at risk for AD and for predicting subtle cognitive decline and conversion to mild cognitive impairment and AD. Taken together, this evidence not only implicates CBF as a useful biomarker for tracking disease severity and progression, but also suggests that ASL-measured CBF may be useful for identifying candidates for future AD treatment trials, especially in the preclinical, asymptomatic phases of the disease.
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Affiliation(s)
- Chelsea C Hays
- VA San Diego Healthcare System, 3350 La Jolla Village Dr., MC 151B, San Diego, CA, 92161, USA.,SDSU/UC San Diego Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Court, Suite 103, San Diego, CA, 92120, USA
| | - Zvinka Z Zlatar
- VA San Diego Healthcare System, 3350 La Jolla Village Dr., MC 151B, San Diego, CA, 92161, USA.,Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Christina E Wierenga
- VA San Diego Healthcare System, 3350 La Jolla Village Dr., MC 151B, San Diego, CA, 92161, USA. .,Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA.
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Sokolova IB, Puzanov MV, Melnykova NN, Mourovets VO, Sergeev IV, Dvoretsky DP. Aging-related changes in the blood flow rate and oxygen saturation of the blood in the cerebral cortex of rats. ADVANCES IN GERONTOLOGY 2016. [DOI: 10.1134/s2079057016010124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Di Bernardi Luft C, Baker R, Bentham P, Kourtzi Z. Learning temporal statistics for sensory predictions in mild cognitive impairment. Neuropsychologia 2015; 75:368-80. [PMID: 26093288 DOI: 10.1016/j.neuropsychologia.2015.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 05/28/2015] [Accepted: 06/02/2015] [Indexed: 10/23/2022]
Abstract
Training is known to improve performance in a variety of perceptual and cognitive skills. However, there is accumulating evidence that mere exposure (i.e. without supervised training) to regularities (i.e. patterns that co-occur in the environment) facilitates our ability to learn contingencies that allow us to interpret the current scene and make predictions about future events. Recent neuroimaging studies have implicated fronto-striatal and medial temporal lobe brain regions in the learning of spatial and temporal statistics. Here, we ask whether patients with mild cognitive impairment due to Alzheimer's disease (MCI-AD) that are characterized by hippocampal dysfunction are able to learn temporal regularities and predict upcoming events. We tested the ability of MCI-AD patients and age-matched controls to predict the orientation of a test stimulus following exposure to sequences of leftwards or rightwards orientated gratings. Our results demonstrate that exposure to temporal sequences without feedback facilitates the ability to predict an upcoming stimulus in both MCI-AD patients and controls. However, our fMRI results demonstrate that MCI-AD patients recruit an alternate circuit to hippocampus to succeed in learning of predictive structures. In particular, we observed stronger learning-dependent activations for structured sequences in frontal, subcortical and cerebellar regions for patients compared to age-matched controls. Thus, our findings suggest a cortico-striatal-cerebellar network that may mediate the ability for predictive learning despite hippocampal dysfunction in MCI-AD.
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Affiliation(s)
| | - Rosalind Baker
- School of Psychology, University of Birmingham, Birmingham B15 2TT, UK
| | - Peter Bentham
- Birmingham and Solihull Mental Health Foundation Trust (BSMHFT), Edgbaston, Birmingham, UK
| | - Zoe Kourtzi
- Department of Psychology, University of Cambridge, Cambridge, UK.
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Tsvetanov KA, Henson RNA, Tyler LK, Davis SW, Shafto MA, Taylor JR, Williams N, Cam-Can, Rowe JB. The effect of ageing on fMRI: Correction for the confounding effects of vascular reactivity evaluated by joint fMRI and MEG in 335 adults. Hum Brain Mapp 2015; 36:2248-69. [PMID: 25727740 PMCID: PMC4730557 DOI: 10.1002/hbm.22768] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 02/04/2015] [Accepted: 02/05/2015] [Indexed: 11/08/2022] Open
Abstract
In functional magnetic resonance imaging (fMRI) research one is typically interested in neural activity. However, the blood‐oxygenation level‐dependent (BOLD) signal is a composite of both neural and vascular activity. As factors such as age or medication may alter vascular function, it is essential to account for changes in neurovascular coupling when investigating neurocognitive functioning with fMRI. The resting‐state fluctuation amplitude (RSFA) in the fMRI signal (rsfMRI) has been proposed as an index of vascular reactivity. The RSFA compares favourably with other techniques such as breath‐hold and hypercapnia, but the latter are more difficult to perform in some populations, such as older adults. The RSFA is therefore a candidate for use in adjusting for age‐related changes in vascular reactivity in fMRI studies. The use of RSFA is predicated on its sensitivity to vascular rather than neural factors; however, the extent to which each of these factors contributes to RSFA remains to be characterized. The present work addressed these issues by comparing RSFA (i.e., rsfMRI variability) to proxy measures of (i) cardiovascular function in terms of heart rate (HR) and heart rate variability (HRV) and (ii) neural activity in terms of resting state magnetoencephalography (rsMEG). We derived summary scores of RSFA, a sensorimotor task BOLD activation, cardiovascular function and rsMEG variability for 335 healthy older adults in the population‐based Cambridge Centre for Ageing and Neuroscience cohort (Cam‐CAN; http://www.cam-can.com). Mediation analysis revealed that the effects of ageing on RSFA were significantly mediated by vascular factors, but importantly not by the variability in neuronal activity. Furthermore, the converse effects of ageing on the rsMEG variability were not mediated by vascular factors. We then examined the effect of RSFA scaling of task‐based BOLD in the sensorimotor task. The scaling analysis revealed that much of the effects of age on task‐based activation studies with fMRI do not survive correction for changes in vascular reactivity, and are likely to have been overestimated in previous fMRI studies of ageing. The results from the mediation analysis demonstrate that RSFA is modulated by measures of vascular function and is not driven solely by changes in the variance of neural activity. Based on these findings we propose that the RSFA scaling method is articularly useful in large scale and longitudinal neuroimaging studies of ageing, or with frail participants, where alternative measures of vascular reactivity are impractical. Hum Brain Mapp 36:2248–2269, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Kamen A Tsvetanov
- Centre for Speech, Language and the Brain, Department of Psychology, University of Cambridge, Cambridge, United Kingdom
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Meusel LAC, Kansal N, Tchistiakova E, Yuen W, MacIntosh BJ, Greenwood CE, Anderson ND. A systematic review of type 2 diabetes mellitus and hypertension in imaging studies of cognitive aging: time to establish new norms. Front Aging Neurosci 2014; 6:148. [PMID: 25071557 PMCID: PMC4085499 DOI: 10.3389/fnagi.2014.00148] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 06/17/2014] [Indexed: 12/19/2022] Open
Abstract
The rising prevalence of type 2 diabetes (T2DM) and hypertension in older adults, and the deleterious effect of these conditions on cerebrovascular and brain health, is creating a growing discrepancy between the "typical" cognitive aging trajectory and a "healthy" cognitive aging trajectory. These changing health demographics make T2DM and hypertension important topics of study in their own right, and warrant attention from the perspective of cognitive aging neuroimaging research. Specifically, interpretation of individual or group differences in blood oxygenation level dependent magnetic resonance imaging (BOLD MRI) or positron emission tomography (PET H2O(15)) signals as reflective of differences in neural activation underlying a cognitive operation of interest requires assumptions of intact vascular health amongst the study participants. Without adequate screening, inclusion of individuals with T2DM or hypertension in "healthy" samples may introduce unwanted variability and bias to brain and/or cognitive measures, and increase potential for error. We conducted a systematic review of the cognitive aging neuroimaging literature to document the extent to which researchers account for these conditions. Of the 232 studies selected for review, few explicitly excluded individuals with T2DM (9%) or hypertension (13%). A large portion had exclusion criteria that made it difficult to determine whether T2DM or hypertension were excluded (44 and 37%), and many did not mention any selection criteria related to T2DM or hypertension (34 and 22%). Of all the surveyed studies, only 29% acknowledged or addressed the potential influence of intersubject vascular variability on the measured BOLD or PET signals. To reinforce the notion that individuals with T2DM and hypertension should not be overlooked as a potential source of bias, we also provide an overview of metabolic and vascular changes associated with T2DM and hypertension, as they relate to cerebrovascular and brain health.
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Affiliation(s)
| | - Nisha Kansal
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada
| | - Ekaterina Tchistiakova
- Sunnybrook Research Institute, Heart and Stroke Foundation Canadian Partnership for Stroke Recovery Toronto, ON, Canada ; Department of Medical Biophysics, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - William Yuen
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Department of Nutritional Sciences, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Bradley J MacIntosh
- Sunnybrook Research Institute, Heart and Stroke Foundation Canadian Partnership for Stroke Recovery Toronto, ON, Canada ; Department of Medical Biophysics, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Carol E Greenwood
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Department of Nutritional Sciences, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Nicole D Anderson
- Baycrest Centre, Rotman Research Institute Toronto, ON, Canada ; Departments of Psychology and Psychiatry, University of Toronto Toronto, ON, Canada
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Bangen KJ, Nation DA, Clark LR, Harmell AL, Wierenga CE, Dev SI, Delano-Wood L, Zlatar ZZ, Salmon DP, Liu TT, Bondi MW. Interactive effects of vascular risk burden and advanced age on cerebral blood flow. Front Aging Neurosci 2014; 6:159. [PMID: 25071567 PMCID: PMC4083452 DOI: 10.3389/fnagi.2014.00159] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 06/19/2014] [Indexed: 01/24/2023] Open
Abstract
Vascular risk factors and cerebral blood flow (CBF) reduction have been linked to increased risk of cognitive impairment and Alzheimer's disease (AD); however the possible moderating effects of age and vascular risk burden on CBF in late life remain understudied. We examined the relationships among elevated vascular risk burden, age, CBF, and cognition. Seventy-one non-demented older adults completed an arterial spin labeling MR scan, neuropsychological assessment, and medical history interview. Relationships among vascular risk burden, age, and CBF were examined in a priori regions of interest (ROIs) previously implicated in aging and AD. Interaction effects indicated that, among older adults with elevated vascular risk burden (i.e., multiple vascular risk factors), advancing age was significantly associated with reduced cortical CBF whereas there was no such relationship for those with low vascular risk burden (i.e., no or one vascular risk factor). This pattern was observed in cortical ROIs including medial temporal (hippocampus, parahippocampal gyrus, uncus), inferior parietal (supramarginal gyrus, inferior parietal lobule, angular gyrus), and frontal (anterior cingulate, middle frontal gyrus, medial frontal gyrus) cortices. Furthermore, among those with elevated vascular risk, reduced CBF was associated with poorer cognitive performance. Such findings suggest that older adults with elevated vascular risk burden may be particularly vulnerable to cognitive change as a function of CBF reductions. Findings support the use of CBF as a potential biomarker in preclinical AD and suggest that vascular risk burden and regionally-specific CBF changes may contribute to differential age-related cognitive declines.
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Affiliation(s)
- Katherine J Bangen
- Psychology Service, VA San Diego Healthcare System San Diego, CA, USA ; Department of Psychiatry, University of California, San Diego La Jolla, CA, USA
| | - Daniel A Nation
- Department of Psychology, University of Southern California Los Angeles, CA, USA
| | - Lindsay R Clark
- San Diego Joint Doctoral Program in Clinical Psychology, San Diego State University/University of California San Diego, CA, USA
| | - Alexandrea L Harmell
- San Diego Joint Doctoral Program in Clinical Psychology, San Diego State University/University of California San Diego, CA, USA
| | - Christina E Wierenga
- Department of Psychiatry, University of California, San Diego La Jolla, CA, USA ; Research Service, VA San Diego Healthcare System San Diego, CA, USA
| | - Sheena I Dev
- San Diego Joint Doctoral Program in Clinical Psychology, San Diego State University/University of California San Diego, CA, USA
| | - Lisa Delano-Wood
- Department of Psychiatry, University of California, San Diego La Jolla, CA, USA ; Research Service, VA San Diego Healthcare System San Diego, CA, USA
| | - Zvinka Z Zlatar
- Department of Psychiatry, University of California, San Diego La Jolla, CA, USA
| | - David P Salmon
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Thomas T Liu
- Department of Radiology, University of California San Diego, La Jolla, CA, USA
| | - Mark W Bondi
- Psychology Service, VA San Diego Healthcare System San Diego, CA, USA ; Department of Psychiatry, University of California, San Diego La Jolla, CA, USA
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37
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Konishi K, Etchamendy N, Roy S, Marighetto A, Rajah N, Bohbot VD. Decreased functional magnetic resonance imaging activity in the hippocampus in favor of the caudate nucleus in older adults tested in a virtual navigation task. Hippocampus 2014; 23:1005-14. [PMID: 23929534 DOI: 10.1002/hipo.22181] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 11/05/2022]
Abstract
The neuroimaging literature has shown consistent decreases in functional magnetic resonance imaging (fMRI) activity in the hippocampus of healthy older adults engaged in a navigation task. However, navigation in a virtual maze relies on spatial or response strategies known to depend on the hippocampus and caudate nucleus, respectively. Therefore, since the proportion of people using spatial strategies decreases with normal aging, we hypothesized that it was responsible for the observed decreases in fMRI activity in the hippocampus reported in the literature. The aim of this study was to examine the effects of aging on the hippocampus and caudate nucleus during navigation while taking into account individual navigational strategies. Young (N = 23) and older adults (N = 29) were tested using fMRI on the Concurrent Spatial Discrimination Learning Task, a radial task that dissociates between spatial and response strategies (in Stage 2) after participants reached criteria (in Stage 1). Success on Stage 2 requires that participants have encoded the spatial relationship between the target object and environmental landmarks, that is, the spatial strategy. While older adults required more trials, all participants reached criterion. fMRI results showed that, as a group, young adults had significant activity in the hippocampus as opposed to older adults who instead had significant activity in the caudate nucleus. Importantly, individual differences showed that the older participants who used a spatial strategy to solve the task had significant activity in the hippocampus. These findings suggest that the aging process involves a shift from using the hippocampus toward the caudate nucleus during navigation but that activity in the hippocampus is sustained in a subset of healthy older adults engaged in spatial strategies.
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Affiliation(s)
- Kyoko Konishi
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Verdun, Quebec, Canada
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Derksen BJ, Duff MC, Weldon K, Zhang J, Zamba KD, Tranel D, Denburg NL. Older adults catch up to younger adults on a learning and memory task that involves collaborative social interaction. Memory 2014; 23:612-24. [PMID: 24841619 PMCID: PMC4237685 DOI: 10.1080/09658211.2014.915974] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Learning and memory abilities tend to decline as people age. The current study examines the question of whether a learning situation that emphasises collaborative social interaction might help older persons overcome age-related learning and memory changes and thus perform similarly to younger persons. Younger and Older participants (n = 34 in each group) completed the Barrier Task (BT), a game-like social interaction where partners work together to develop labels for a set of abstract tangrams. Participants were also administered standard clinical neuropsychological measures of memory, on which the Older group showed expected inferiority to the Younger group. On the BT, the Older group performed less well than the Younger group early on, but as the task progressed, the performance of the Older group caught up and became statistically indistinguishable from that of the Younger group. These results can be taken to suggest that a learning milieu characterised by collaborative social interaction can attenuate some of the typical memory disadvantages associated with being older.
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Affiliation(s)
- B J Derksen
- a Department of Neurology, Division of Cognitive Neuroscience , University of Iowa Carver College of Medicine , Iowa City , IA , USA
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Talati P, Rane S, Kose S, Gore J, Heckers S. Anterior-posterior cerebral blood volume gradient in human subiculum. Hippocampus 2014; 24:503-9. [PMID: 24677295 DOI: 10.1002/hipo.22257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/31/2014] [Accepted: 01/31/2014] [Indexed: 12/29/2022]
Abstract
The human hippocampal formation is characterized by anterior-posterior gradients of cell density, neurochemistry, and hemodynamics. In addition, some functions are associated with specific subfields (subiculum, CA1-4, dentate gyrus) and regions (anterior and posterior). We performed contrast-enhanced, high-resolution T1-weighted 3T steady state (SS) imaging to investigate cerebral blood volume (CBV) gradients of the hippocampal formation. We studied 14 healthy subjects and found significant CBV gradients (anterior > posterior) in the subiculum but not in other hippocampal subfields. Since CBV is a marker of basal metabolism, these results indicate a greater baseline activity in the anterior compared with the posterior subiculum. This gradient might be related to the role of the subiculum as the main outflow station of the hippocampal formation and might have implications for the mechanisms of neuropsychiatric disorders.
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Affiliation(s)
- Pratik Talati
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Department of Psychiatry, Vanderbilt University, Nashville, Tennessee
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Chiu PW, Mak HKF, Yau KKW, Chan Q, Chang RCC, Chu LW. Metabolic changes in the anterior and posterior cingulate cortices of the normal aging brain: proton magnetic resonance spectroscopy study at 3 T. AGE (DORDRECHT, NETHERLANDS) 2014; 36:251-64. [PMID: 23709317 PMCID: PMC3889884 DOI: 10.1007/s11357-013-9545-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 05/14/2013] [Indexed: 05/22/2023]
Abstract
Magnetic resonance spectroscopy (MRS) can explore aging at a molecular level. In this study, we investigated the relationships between regional concentrations of metabolites (such as choline, creatine, myo-inositol, and N-acetyl-aspartate) and normal aging in 30 cognitively normal subjects (15 women and 15 men, age range 22-82, mean = 49.9 ± 18.3 years) using quantitative proton magnetic resonance spectroscopy. All MR scans were performed using a 3 T scanner. Point resolved spectroscopy was used as the volume selection method for the region-of-interest and the excitation method for water suppression. Single voxel spectroscopy with short echo time of 39 ms and repetition time of 2,000 ms was employed. Single voxels were placed in the limbic regions, i.e., anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and left and right hippocampi. Cerebrospinal fluid normalization and T1 and T2 correction factors were implemented in the calculation of absolute metabolite concentrations. A standardized T1W 3D volumetric fast field echo and axial T2-weighted fast spin-echo images were also acquired. Our results showed significant positive correlation of choline (r = 0.545, p = 0.002), creatine (r = 0.571, p = 0.001), and N-acetyl-aspartate (r = 0.674, p < 0.001) in the ACC; choline (r = 0.614, p < 0.001), creatine (r = 0.670, p < 0.001), and N-acetyl-aspartate (r = 0.528, p = 0.003) in the PCC; and NAA (r = 0.409, p = 0.025) in the left hippocampus, with age. No significant gender effect on metabolite concentrations was found. In aging, increases in choline and creatine might suggest glial proliferation, and an increase in N-acetyl-aspartate might indicate neuronal hypertrophy. Such findings highlight the metabolic changes of ACC and PCC with age, which could be compensatory to an increased energy demand coupled with a lower cerebral blood flow.
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Affiliation(s)
- Pui-Wai Chiu
- />Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Henry Ka-Fung Mak
- />Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- />Alzheimer’s Disease Research Network, The University of Hong Kong, Hong Kong, China
- />Research Centre of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- />Queen Mary Hospital, Room 406, Block K, 102 Pokfulam Road, Hong Kong, China
| | - Kelvin Kai-Wing Yau
- />Department of Management Sciences, City University of Hong Kong, Hong Kong, China
| | - Queenie Chan
- />Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- />Philips Healthcare, Hong Kong, China
| | - Raymond Chuen-Chung Chang
- />Laboratory of Neurodegenerative Disease, Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- />Alzheimer’s Disease Research Network, The University of Hong Kong, Hong Kong, China
- />Research Centre of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Leung-Wing Chu
- />Division of Geriatric Medicine, Department of Medicine, Queen Mary Hospital, Hong Kong, China
- />Alzheimer’s Disease Research Network, The University of Hong Kong, Hong Kong, China
- />Research Centre of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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Desjardins M, Berti R, Pouliot P, Dubeau S, Lesage F. Multimodal study of the hemodynamic response to hypercapnia in anesthetized aged rats. Neurosci Lett 2014; 563:33-7. [PMID: 24480251 DOI: 10.1016/j.neulet.2014.01.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/13/2014] [Accepted: 01/17/2014] [Indexed: 10/25/2022]
Abstract
With aging, the brain undergoes changes in metabolism and perfusion, both of which influence the widely used blood-oxygenation-level-dependent (BOLD) MRI signal. To isolate the vascular effects associated with age, this study measured the response to a hypercapnic challenge using different imaging modalities in 19 young (3 months-old) and 13 old (24 months-old) Long-Evans rats. Intrinsic optical imaging was used to measure oxy (HbO), deoxy (HbR) and total (HbT) hemoglobin concentration changes, laser speckle for cerebral blood flow (CBF) changes, and MRI for the BOLD signal. Older rats had smaller HbO (41% smaller), HbT (50%) and CBF (34%) responses, but the temporal dynamics did not exhibit significant age differences. The ratio of CBV to CBF responses was also smaller in older adults, potentially indicating a change in the compliance of vessels.
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Affiliation(s)
- Michèle Desjardins
- Institut de Génie Biomédical, Dpt. de Génie Électrique, École Polytechnique de Montréal, C.P. 6079, succ. Centre-ville, Montréal, QC, H3C 3A7, Canada; Montreal Heart Institute, 5000 rue Bélanger, Montréal, QC, H1T 1C8, Canada.
| | - Romain Berti
- Institut de Génie Biomédical, Dpt. de Génie Électrique, École Polytechnique de Montréal, C.P. 6079, succ. Centre-ville, Montréal, QC, H3C 3A7, Canada; Montreal Heart Institute, 5000 rue Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Philippe Pouliot
- Institut de Génie Biomédical, Dpt. de Génie Électrique, École Polytechnique de Montréal, C.P. 6079, succ. Centre-ville, Montréal, QC, H3C 3A7, Canada; Montreal Heart Institute, 5000 rue Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Simon Dubeau
- Institut de Génie Biomédical, Dpt. de Génie Électrique, École Polytechnique de Montréal, C.P. 6079, succ. Centre-ville, Montréal, QC, H3C 3A7, Canada; Montreal Heart Institute, 5000 rue Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Frédéric Lesage
- Institut de Génie Biomédical, Dpt. de Génie Électrique, École Polytechnique de Montréal, C.P. 6079, succ. Centre-ville, Montréal, QC, H3C 3A7, Canada; Montreal Heart Institute, 5000 rue Bélanger, Montréal, QC, H1T 1C8, Canada
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42
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Di X, Rypma B, Biswal BB. Correspondence of executive function related functional and anatomical alterations in aging brain. Prog Neuropsychopharmacol Biol Psychiatry 2014; 48:41-50. [PMID: 24036319 PMCID: PMC3870052 DOI: 10.1016/j.pnpbp.2013.09.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 08/19/2013] [Accepted: 09/03/2013] [Indexed: 11/28/2022]
Abstract
Neurocognitive aging studies have focused on age-related changes in neural activity or neural structure but few studies have focused on relationships between the two. The present study quantitatively reviewed 24 studies of age-related changes in fMRI activation across a broad spectrum of executive function tasks using activation likelihood estimation (ALE) and 22 separate studies of age-related changes in gray matter using voxel-based morphometry (VBM). Conjunction analyses between functional and structural alteration maps were constructed. Overlaps were only observed in the conjunction of dorsolateral prefrontal cortex (DLPFC) gray matter reduction and functional hyperactivation but not hypoactivation. It was not evident that the conjunctions between gray matter and activation were related to task performance. Theoretical implications of these results are discussed.
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Affiliation(s)
- Xin Di
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07101, USA.
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Bharat B. Biswal
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07101, USA
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Bouzerar R, Chaarani B, Gondry-Jouet C, Zmudka J, Balédent O. Measurement of choroid plexus perfusion using dynamic susceptibility MR imaging: capillary permeability and age-related changes. Neuroradiology 2013; 55:1447-54. [DOI: 10.1007/s00234-013-1290-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/07/2013] [Indexed: 11/24/2022]
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Hutchison JL, Lu H, Rypma B. Neural mechanisms of age-related slowing: the ΔCBF/ΔCMRO2 ratio mediates age-differences in BOLD signal and human performance. Cereb Cortex 2013; 23:2337-46. [PMID: 22879349 PMCID: PMC3767961 DOI: 10.1093/cercor/bhs233] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The precise mechanisms that give rise to the blood-oxygen-level-dependent (BOLD) activation differences that accompany age-related cognitive slowing remain fundamentally unknown. We sought to isolate the origin of age-related BOLD changes by comparing blood-flow and oxygen-metabolic constituents of the BOLD response using dual-echo arterial spin labeling during visual stimulation and CO2 ingestion. We hypothesized, and our results confirmed, that age-related changes in the ratio of fractional cerebral blood flow to fractional cerebral metabolic rate of oxygen consumption (ΔCBF/ΔCMRO2) lead to the BOLD changes that are observed in older adults. ΔCBF/ΔCMRO2 was also significantly related to performance, suggesting that age-related cognitive slowing results from neural cell assemblies that operate less efficiently, requiring greater oxygen metabolism that is not matched by blood-flow changes relative to younger adults. Age-related changes in ΔCBF/ΔCMRO2 are sufficient to explain variations in BOLD responding and performance cited throughout the literature, assuming no bias based on physiological baseline CMRO2.
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Affiliation(s)
- Joanna L Hutchison
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
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Krainik A, Villien M, Troprès I, Attyé A, Lamalle L, Bouvier J, Pietras J, Grand S, Le Bas JF, Warnking J. Functional imaging of cerebral perfusion. Diagn Interv Imaging 2013; 94:1259-78. [PMID: 24011870 DOI: 10.1016/j.diii.2013.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The functional imaging of perfusion enables the study of its properties such as the vasoreactivity to circulating gases, the autoregulation and the neurovascular coupling. Downstream from arterial stenosis, this imaging can estimate the vascular reserve and the risk of ischemia in order to adapt the therapeutic strategy. This method reveals the hemodynamic disorders in patients suffering from Alzheimer's disease or with arteriovenous malformations revealed by epilepsy. Functional MRI of the vasoreactivity also helps to better interpret the functional MRI activation in practice and in clinical research.
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Affiliation(s)
- A Krainik
- Clinique universitaire de neuroradiologie et IRM, CHU de Grenoble, CS 10217, 38043 Grenoble cedex, France; Inserm U836, université Joseph-Fourier, site santé, chemin Fortuné-Ferrini, 38706 La Tronche cedex, France; UMS IRMaGe, unité IRM 3T recherche, CHU de Grenoble, CS 10217, 38043 Grenoble cedex 9, France.
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Mitochondrial calcium uptake capacity modulates neocortical excitability. J Cereb Blood Flow Metab 2013; 33:1115-26. [PMID: 23591650 PMCID: PMC3705442 DOI: 10.1038/jcbfm.2013.61] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Revised: 03/14/2013] [Accepted: 03/15/2013] [Indexed: 12/25/2022]
Abstract
Local calcium (Ca(2+)) changes regulate central nervous system metabolism and communication integrated by subcellular processes including mitochondrial Ca(2+) uptake. Mitochondria take up Ca(2+) through the calcium uniporter (mCU) aided by cytoplasmic microdomains of high Ca(2+). Known only in vitro, the in vivo impact of mCU activity may reveal Ca(2+)-mediated roles of mitochondria in brain signaling and metabolism. From in vitro studies of mitochondrial Ca(2+) sequestration and cycling in various cell types of the central nervous system, we evaluated ranges of spontaneous and activity-induced Ca(2+) distributions in multiple subcellular compartments in vivo. We hypothesized that inhibiting (or enhancing) mCU activity would attenuate (or augment) cortical neuronal activity as well as activity-induced hemodynamic responses in an overall cytoplasmic and mitochondrial Ca(2+)-dependent manner. Spontaneous and sensory-evoked cortical activities were measured by extracellular electrophysiology complemented with dynamic mapping of blood oxygen level dependence and cerebral blood flow. Calcium uniporter activity was inhibited and enhanced pharmacologically, and its impact on the multimodal measures were analyzed in an integrated manner. Ru360, an mCU inhibitor, reduced all stimulus-evoked responses, whereas Kaempferol, an mCU enhancer, augmented all evoked responses. Collectively, the results confirm aforementioned hypotheses and support the Ca(2+) uptake-mediated integrative role of in vivo mitochondria on neocortical activity.
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Hutchison JL, Shokri-Kojori E, Lu H, Rypma B. A BOLD Perspective on Age-Related Neurometabolic-Flow Coupling and Neural Efficiency Changes in Human Visual Cortex. Front Psychol 2013; 4:244. [PMID: 23653614 PMCID: PMC3642502 DOI: 10.3389/fpsyg.2013.00244] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Accepted: 04/14/2013] [Indexed: 11/22/2022] Open
Abstract
Age-related performance declines in visual tasks have been attributed to reductions in processing efficiency. The neural basis of these declines has been explored by comparing the blood-oxygen-level-dependent (BOLD) index of neural activity in older and younger adults during visual task performance. However, neural activity is one of many factors that change with age and lead to BOLD signal differences. We investigated the origin of age-related BOLD changes by comparing blood flow and oxygen metabolic constituents of BOLD signal. Subjects periodically viewed flickering annuli and pressed a button when detecting luminance changes in a central fixation cross. Using magnetic resonance dual-echo arterial spin labeling and CO2 ingestion, we observed age-equivalent (i.e., similar in older and younger groups) fractional cerebral blood flow (ΔCBF) in the presence of age-related increases in fractional cerebral metabolic rate of oxygen (ΔCMRO2). Reductions in ΔCBF responsiveness to increased ΔCMRO2 in elderly led to paradoxical age-related BOLD decreases. Age-related ΔCBF/ΔCMRO2 ratio decreases were associated with reaction times, suggesting that age-related slowing resulted from less efficient neural activity. We hypothesized that reduced vascular responsiveness to neural metabolic demand would lead to a reduction in ΔCBF/ΔCMRO2. A simulation of BOLD relative to ΔCMRO2 for lower and higher neurometabolic-flow coupling ratios (approximating those for old and young, respectively) indicated less BOLD signal change in old than young in relatively lower CMRO2 ranges, as well as greater BOLD signal change in young compared to old in relatively higher CMRO2 ranges. These results suggest that age-comparative studies relying on BOLD signal might be misinterpreted, as age-related BOLD changes do not merely reflect neural activity changes. Age-related declines in neurometabolic-flow coupling might lead to neural efficiency reductions that can adversely affect visual task performance.
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Affiliation(s)
- Joanna Lynn Hutchison
- School of Behavioral and Brain Sciences, University of Texas at DallasRichardson, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical CenterDallas, TX, USA
| | - Ehsan Shokri-Kojori
- School of Behavioral and Brain Sciences, University of Texas at DallasRichardson, TX, USA
| | - Hanzhang Lu
- Advanced Imaging Research Center, University of Texas Southwestern Medical CenterDallas, TX, USA
| | - Bart Rypma
- School of Behavioral and Brain Sciences, University of Texas at DallasRichardson, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical CenterDallas, TX, USA
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Age-related differences in memory-encoding fMRI responses after accounting for decline in vascular reactivity. Neuroimage 2013; 78:415-25. [PMID: 23624491 DOI: 10.1016/j.neuroimage.2013.04.053] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 04/02/2013] [Accepted: 04/15/2013] [Indexed: 11/22/2022] Open
Abstract
BOLD fMRI has provided a wealth of information about the aging brain. A common finding is that posterior regions of the brain manifest an age-related decrease in activation while the anterior regions show an age-related increase. Several neurocognitive models have been proposed to interpret these findings. However, one issue that has not been sufficiently considered to date is that the BOLD signal is based on vascular responses secondary to neural activity. Thus the above findings could be in part due to a vascular change, especially in view of the expected decline of vascular health with age. In the present study, we aim to examine age-related differences in memory-encoding fMRI response in the context of vascular aging. One hundred and thirty healthy subjects ranging from 20 to 89 years old underwent a scene-viewing fMRI task and, in the same session, cerebrovascular reactivity (CVR) was measured in each subject using a CO2-inhalation task. Without accounting for the influence of vascular changes, the task-activated fMRI signal showed the typical age-related decrease in visual cortex and medial temporal lobe (MTL), but manifested an increase in the right inferior frontal gyrus (IFG). In the same individuals, an age-related CVR reduction was observed in all of these regions. We then used a previously proposed normalization approach to calculate a CVR-corrected fMRI signal, which was defined as the uncorrected signal divided by CVR. Based on the CVR-corrected fMRI signal, an age-related increase is now seen in both the left and right sides of IFG; and no brain regions showed a signal decrease with age. We additionally used a model-based approach to examine the fMRI data in the context of CVR, which again suggested an age-related change in the two frontal regions, but not in the visual and MTL regions.
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Liu TT, Glover GH, Mueller BA, Greve DN, Brown GG. An introduction to normalization and calibration methods in functional MRI. PSYCHOMETRIKA 2013; 78:308-21. [PMID: 25107618 DOI: 10.1007/s11336-012-9309-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 02/15/2012] [Indexed: 05/26/2023]
Abstract
In functional magnetic resonance imaging (fMRI), the blood oxygenation level dependent (BOLD) signal is often interpreted as a measure of neural activity. However, because the BOLD signal reflects the complex interplay of neural, vascular, and metabolic processes, such an interpretation is not always valid. There is growing evidence that changes in the baseline neurovascular state can result in significant modulations of the BOLD signal that are independent of changes in neural activity. This paper introduces some of the normalization and calibration methods that have been proposed for making the BOLD signal a more accurate reflection of underlying brain activity for human fMRI studies.
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Affiliation(s)
- Thomas T Liu
- Center for Functional MRI, University of California San Diego, 9500 Gilman Drive, MC 0677, La Jolla, CA, 92093, USA,
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Mayhew SD, Kourtzi Z. Dissociable circuits for visual shape learning in the young and aging human brain. Front Hum Neurosci 2013; 7:75. [PMID: 23543881 PMCID: PMC3608912 DOI: 10.3389/fnhum.2013.00075] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 02/25/2013] [Indexed: 11/13/2022] Open
Abstract
Recognizing objects in cluttered scenes is vital for successful interactions in our complex environments. Learning is known to play a key role in facilitating performance in a wide range of perceptual skills not only in young but also older adults. However, the neural mechanisms that support our ability to improve visual form recognition with training in older age remain largely unknown. Here, we combine behavioral and fMRI measurements to identify the brain circuits involved in the learning of global visual forms in the aging human brain. Our findings demonstrate the learning enhances perceptual sensitivity in the discrimination of visual forms similarly in both young and older adults. However, using fMRI we show that the neural circuits involved in visual form learning differ with age. Our results show that in young adults visual shape learning engages a network of occipitotemporal, parietal, and frontal regions that is known to be involved in perceptual decisions. In contrast, in older adults visual shape learning engages primarily parietal regions, suggesting a stronger role of attentionally-guided learning in older age. Interestingly, learning-dependent changes are maintained in higher occipitotemporal and posterior parietal regions, but not in frontal circuits, when observers perform a control task rather than engaging in a visual form discrimination task. Thus, learning may modulate read-out signals in posterior regions related to global form representations independent of the task, whereas task-dependent frontal activations may reflect changes in sensitivity with training in the context of perceptual decision making.
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