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Guilbert J, Légaré A, De Koninck P, Desrosiers P, Desjardins M. Toward an integrative neurovascular framework for studying brain networks. NEUROPHOTONICS 2022; 9:032211. [PMID: 35434179 PMCID: PMC8989057 DOI: 10.1117/1.nph.9.3.032211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/11/2022] [Indexed: 05/28/2023]
Abstract
Brain functional connectivity based on the measure of blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signals has become one of the most widely used measurements in human neuroimaging. However, the nature of the functional networks revealed by BOLD fMRI can be ambiguous, as highlighted by a recent series of experiments that have suggested that typical resting-state networks can be replicated from purely vascular or physiologically driven BOLD signals. After going through a brief review of the key concepts of brain network analysis, we explore how the vascular and neuronal systems interact to give rise to the brain functional networks measured with BOLD fMRI. This leads us to emphasize a view of the vascular network not only as a confounding element in fMRI but also as a functionally relevant system that is entangled with the neuronal network. To study the vascular and neuronal underpinnings of BOLD functional connectivity, we consider a combination of methodological avenues based on multiscale and multimodal optical imaging in mice, used in combination with computational models that allow the integration of vascular information to explain functional connectivity.
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Affiliation(s)
- Jérémie Guilbert
- Université Laval, Department of Physics, Physical Engineering, and Optics, Québec, Canada
- Université Laval, Centre de recherche du CHU de Québec, Québec, Canada
| | - Antoine Légaré
- Université Laval, Department of Physics, Physical Engineering, and Optics, Québec, Canada
- Centre de recherche CERVO, Québec, Canada
- Université Laval, Department of Biochemistry, Microbiology, and Bioinformatics, Québec, Canada
| | - Paul De Koninck
- Centre de recherche CERVO, Québec, Canada
- Université Laval, Department of Biochemistry, Microbiology, and Bioinformatics, Québec, Canada
| | - Patrick Desrosiers
- Université Laval, Department of Physics, Physical Engineering, and Optics, Québec, Canada
- Centre de recherche CERVO, Québec, Canada
| | - Michèle Desjardins
- Université Laval, Department of Physics, Physical Engineering, and Optics, Québec, Canada
- Université Laval, Centre de recherche du CHU de Québec, Québec, Canada
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2
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Rastogi R, Morgan BJ, Badr MS, Chowdhuri S. Hypercapnia-induced vasodilation in the cerebral circulation is reduced in older adults with sleep-disordered breathing. J Appl Physiol (1985) 2022; 132:14-23. [PMID: 34709067 PMCID: PMC8721948 DOI: 10.1152/japplphysiol.00347.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The prevalence of sleep-disordered breathing (SDB) is higher in older adults compared with younger individuals. The increased propensity for ventilatory control instability in older adults may contribute to the increased prevalence of central apneas. Reductions in the cerebral vascular response to CO2 may exacerbate ventilatory overshoots and undershoots during sleep. Thus, we hypothesized that hypercapnia-induced cerebral vasodilation (HCVD) will be reduced in older compared with younger adults. In 11 older and 10 younger adults with SDB, blood flow velocity in the middle cerebral artery (MCAV) was measured using Doppler transcranial ultrasonography during multiple steady-state hyperoxic hypercapnic breathing trials while awake, interspersed with room air breathing. Changes in ventilation, MCAV, and mean arterial pressure (MAP) via finger plethysmography during the trials were compared with baseline eupneic values. For each hyperoxic hypercapnic trial, the change (Δ) in MCAV for a corresponding change in end-tidal CO2 and the HCVD or the change in cerebral vascular conductance (MCAV divided by MAP) for a corresponding change in end-tidal CO2 was determined. The hypercapnic ventilatory response was similar between the age groups, as was ΔMCAV/Δ[Formula: see text]. However, compared with young, older adults had a significantly smaller HCVD (1.3 ± 0.7 vs. 2.1 ± 0.6 units/mmHg, P = 0.004). Multivariable analyses demonstrated that age and nadir oxygen saturation during nocturnal polysomnography were significant predictors of HCVD. Thus, our data indicate that older age and SDB-related hypoxia are associated with diminished HCVD. We hypothesize that this impairment in vascular function may contribute to breathing instability during sleep in these individuals.NEW & NOTEWORTHY This study demonstrates, for the first time, in individuals with sleep-disordered breathing (SDB) that aging is associated with decreased hypercapnia-induced cerebral vasodilation (HCVD). In addition to advanced age, the magnitude of nocturnal oxygen desaturation due to SDB is an equal independent predictor of HCVD.
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Affiliation(s)
- R. Rastogi
- 1Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan,2Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, Michigan
| | - B. J. Morgan
- 3Department of Orthopedics and Rehabilitation, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - M. S. Badr
- 1Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan,2Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, Michigan
| | - S. Chowdhuri
- 1Medical Service, Sleep Medicine Section, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan,2Division of Pulmonary/Critical Care and Sleep Medicine, Department of Medicine, Wayne State University School of Medicine, Detroit, Michigan
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3
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Sabra D, Intzandt B, Desjardins-Crepeau L, Langeard A, Steele CJ, Frouin F, Hoge RD, Bherer L, Gauthier CJ. Sex moderations in the relationship between aortic stiffness, cognition, and cerebrovascular reactivity in healthy older adults. PLoS One 2021; 16:e0257815. [PMID: 34582484 PMCID: PMC8478243 DOI: 10.1371/journal.pone.0257815] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 09/10/2021] [Indexed: 11/21/2022] Open
Abstract
It is well established that sex differences exist in the manifestation of vascular diseases. Arterial stiffness (AS) has been associated with changes in cerebrovascular reactivity (CVR) and cognitive decline in aging. Specifically, older adults with increased AS show a decline on executive function (EF) tasks. Interestingly, the relationship between AS and CVR is more complex, where some studies show decreased CVR with increased AS, and others demonstrate preserved CVR despite higher AS. Here, we investigated the possible role of sex on these hemodynamic relationships. Acquisitions were completed in 48 older adults. Pseudo-continuous arterial spin labeling (pCASL) data were collected during a hypercapnia challenge. Aortic pulse wave velocity (PWV) data was acquired using cine phase contrast velocity series. Cognitive function was assessed with a comprehensive neuropsychological battery, and a composite score for EF was calculated using four cognitive tests from the neuropsychological battery. A moderation model test revealed that sex moderated the relationship between PWV and CVR and PWV and EF, but not between CVR and EF. Together, our results indicate that the relationships between central stiffness, cerebral hemodynamics and cognition are in part mediated by sex.
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Affiliation(s)
- Dalia Sabra
- Faculty of Medicine, Department of Biomedical Science, Université de Montreal, Montreal, QC, Canada
- Research Center, Montreal Heart Institute, Montreal, QC, Canada
- Centre de recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
- Department of Medicine, Universite de Montreal, Montreal, QC, Canada
| | - Brittany Intzandt
- Research Center, Montreal Heart Institute, Montreal, QC, Canada
- Centre de recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
- PERFORM Centre, Concordia University, Montreal, QC, Canada
- INDI Department, Concordia University, Montreal, QC, Canada
| | - Laurence Desjardins-Crepeau
- Research Center, Montreal Heart Institute, Montreal, QC, Canada
- Centre de recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
| | - Antoine Langeard
- Research Center, Montreal Heart Institute, Montreal, QC, Canada
- Centre de recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
- Department of Medicine, Universite de Montreal, Montreal, QC, Canada
| | - Christopher J. Steele
- PERFORM Centre, Concordia University, Montreal, QC, Canada
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Department of Psychology, Concordia University, Montreal, QC, Canada
| | | | - Richard D. Hoge
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Montreal Neurological Institute, Montreal, QC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Louis Bherer
- Research Center, Montreal Heart Institute, Montreal, QC, Canada
- Centre de recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
- Department of Medicine, Universite de Montreal, Montreal, QC, Canada
| | - Claudine J. Gauthier
- Research Center, Montreal Heart Institute, Montreal, QC, Canada
- PERFORM Centre, Concordia University, Montreal, QC, Canada
- Physics Department, Concordia University, Montreal, QC, Canada
- * E-mail:
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Mohammadi H, Vincent T, Peng K, Nigam A, Gayda M, Fraser S, Joanette Y, Lesage F, Bherer L. Coronary artery disease and its impact on the pulsatile brain: A functional NIRS study. Hum Brain Mapp 2021; 42:3760-3776. [PMID: 33991155 PMCID: PMC8288102 DOI: 10.1002/hbm.25463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/16/2022] Open
Abstract
Recent studies have reported that optical indices of cerebral pulsatility are associated with cerebrovascular health in older adults. Such indices, including cerebral pulse amplitude and the pulse relaxation function (PRF), have been previously applied to quantify global and regional cerebral pulsatility. The aim of the present study was to determine whether these indices are modulated by cardiovascular status and whether they differ between individuals with low or high cardiovascular risk factors (LCVRF and HCVRF) and coronary artery disease (CAD). A total of 60 older adults aged 57-79 were enrolled in the study. Participants were grouped as LCVRF, HCVRF, and CAD. Participants were asked to walk freely on a gym track while a near-infrared spectroscopy (NIRS) device recorded hemodynamics data. Low-intensity, short-duration walking was used to test whether a brief cardiovascular challenge could increase the difference of pulsatility indices with respect to cardiovascular status. Results indicated that CAD individuals have higher global cerebral pulse amplitude compared with the other groups. Walking reduced global cerebral pulse amplitude and PRF in all groups but did not increase the difference across the groups. Instead, walking extended the spatial distribution of cerebral pulse amplitude to the anterior prefrontal cortex when CAD was compared to the CVRF groups. Further research is needed to determine whether cerebral pulse amplitude extracted from data acquired with NIRS, which is a noninvasive, inexpensive method, can provide an index to characterize the cerebrovascular status associated with CAD.
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Affiliation(s)
- Hanieh Mohammadi
- Laboratory of Optical and Molecular ImagingBiomedical Engineering Institute, Polytechnique MontrealQuebecCanada
- Research CenterUniversity Institute of Geriatrics of MontrealMontrealQuebecCanada
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Thomas Vincent
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Ke Peng
- Center for Pain and the BrainBoston Children's Hospital and Harvard Medical SchoolBostonMassachusettsUSA
- Research CenterUniversity of Montreal Health CentreMontrealQuebecCanada
| | - Anil Nigam
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Mathieu Gayda
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Sarah Fraser
- Interdisciplinary School of Health Sciences, Faculty of Health SciencesUniversity of OttawaOttawaOntarioCanada
| | - Yves Joanette
- Research CenterUniversity Institute of Geriatrics of MontrealMontrealQuebecCanada
- Faculty of MedicineUniversity of MontrealMontrealQuebecCanada
| | - Frédéric Lesage
- Laboratory of Optical and Molecular ImagingBiomedical Engineering Institute, Polytechnique MontrealQuebecCanada
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
| | - Louis Bherer
- Research CenterUniversity Institute of Geriatrics of MontrealMontrealQuebecCanada
- Research CenterEPIC Centre of Montreal Heart InstituteMontrealQuebecCanada
- Faculty of MedicineUniversity of MontrealMontrealQuebecCanada
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5
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Mohammadi H, Gagnon C, Vincent T, Kassab A, Fraser S, Nigam A, Lesage F, Bherer L. Longitudinal Impact of Physical Activity on Brain Pulsatility Index and Cognition in Older Adults with Cardiovascular Risk Factors: A NIRS Study. Brain Sci 2021; 11:730. [PMID: 34072651 PMCID: PMC8230110 DOI: 10.3390/brainsci11060730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/19/2021] [Accepted: 05/26/2021] [Indexed: 12/11/2022] Open
Abstract
Recent studies have shown that optical indices of cerebral pulsatility, including cerebral pulse amplitude, are linked to cerebrovascular health. A chronically higher cerebral pulsatility is associated with cognitive decline. Although it is widely known that regular physical activity improves cognitive functions, little is known about the association between physical activity and the optical index of cerebral pulsatility. This study assessed the impact of 12 months of regular physical activity on the changes in the optical index of cerebral pulsatility and explored its association with cognition. A total of 19 older adults (aged 59-79 years) with cardiovascular risk factors (CVRF) completed the study. Low-intensity, short-duration walking as a brief cardiovascular challenge was used to study the impact of regular physical activity on post-walking changes in cerebral pulsatility index. The participants walked on a gym track while a near-infrared spectroscopy (NIRS) device recorded hemodynamics data from the frontal and motor cortex subregions. Our data indicated that 12 months of physical activity was associated with lower global cerebral pulse amplitude, which was associated with higher cognitive scores in executive functions. Further, the global cerebral pulsatility index was reduced after short-duration walking, and this reduction was greater after 12 months of regular physical activity compared with the baseline. This may be an indication of improvement in cerebrovascular response to the cardiovascular challenge after regular physical activity. This study suggests that 12 months of physical activity may support cognitive functions through improving cerebral pulsatility in older adults with CVRF.
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Affiliation(s)
- Hanieh Mohammadi
- Montreal Heart Institute, Montreal, QC H1T 1C8, Canada; (H.M.); (C.G.); (T.V.); (A.N.); (F.L.)
- Department of Medicine, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Christine Gagnon
- Montreal Heart Institute, Montreal, QC H1T 1C8, Canada; (H.M.); (C.G.); (T.V.); (A.N.); (F.L.)
| | - Thomas Vincent
- Montreal Heart Institute, Montreal, QC H1T 1C8, Canada; (H.M.); (C.G.); (T.V.); (A.N.); (F.L.)
| | - Ali Kassab
- Research Center, University of Montreal Health Centre, Montreal, QC H2X 3E4, Canada;
| | - Sarah Fraser
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada;
| | - Anil Nigam
- Montreal Heart Institute, Montreal, QC H1T 1C8, Canada; (H.M.); (C.G.); (T.V.); (A.N.); (F.L.)
| | - Frédéric Lesage
- Montreal Heart Institute, Montreal, QC H1T 1C8, Canada; (H.M.); (C.G.); (T.V.); (A.N.); (F.L.)
- Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC H3T 1J4, Canada
| | - Louis Bherer
- Montreal Heart Institute, Montreal, QC H1T 1C8, Canada; (H.M.); (C.G.); (T.V.); (A.N.); (F.L.)
- Department of Medicine, University of Montreal, Montreal, QC H3T 1J4, Canada
- Institut Universitaire de Gériatrie de Montréal, Montreal, QC H3W 1W4, Canada
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Kim D, Hughes TM, Lipford ME, Craft S, Baker LD, Lockhart SN, Whitlow CT, Okonmah-Obazee SE, Hugenschmidt CE, Bobinski M, Jung Y. Relationship Between Cerebrovascular Reactivity and Cognition Among People With Risk of Cognitive Decline. Front Physiol 2021; 12:645342. [PMID: 34135768 PMCID: PMC8201407 DOI: 10.3389/fphys.2021.645342] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 04/29/2021] [Indexed: 11/13/2022] Open
Abstract
Vascular risk factors (e.g., obesity and hypertension) are associated with cerebral small vessel disease, Alzheimer's disease (AD) pathology, and dementia. Reduced perfusion may reflect the impaired ability of blood vessels to regulate blood flow in reaction to varying circumstances such as hypercapnia (increased end-tidal partial pressures of CO2). It has been shown that cerebrovascular reactivity (CVR) measured with blood-oxygen-level-dependent (BOLD) MRI is correlated with cognitive performance and alterations of CVR may be an indicator of vascular disfunction leading to cognitive decline. However, the underlying mechanism of CVR alterations in BOLD signal may not be straight-forward because BOLD signal is affected by multiple physiological parameters, such as cerebral blood flow (CBF), cerebral blood volume, and oxygen metabolism. Arterial spin labeling (ASL) MRI quantitatively measures blood flow in the brain providing images of local CBF. Therefore, in this study, we measured CBF and its changes using a dynamic ASL technique during a hypercapnia challenge and tested if CBF or CVR was related to cognitive performance using the Mini-mental state examination (MMSE) score. Seventy-eight participants underwent cognitive testing and MRI including ASL during a hypercapnia challenge with a RespirAct computer-controlled gas blender, targeting 10 mmHg higher end-tidal CO2 level than the baseline while end-tidal O2 level was maintained. Pseudo-continuous ASL (PCASL) was collected during a 2-min baseline and a 2-min hypercapnic period. CVR was obtained by calculating a percent change of CBF per the end-tidal CO2 elevation in mmHg between the baseline and the hypercapnic challenge. Multivariate regression analyses demonstrated that baseline resting CBF has no significant relationship with MMSE, while lower CVR in the whole brain gray matter (β = 0.689, p = 0.005) and white matter (β = 0.578, p = 0.016) are related to lower MMSE score. In addition, region of interest (ROI) based analysis showed positive relationships between MMSE score and CVR in 26 out of 122 gray matter ROIs.
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Affiliation(s)
- Donghoon Kim
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, United States.,Department of Radiology, University of California, Davis, Davis, CA, United States
| | - Timothy M Hughes
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Megan E Lipford
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Suzanne Craft
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Laura D Baker
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Samuel N Lockhart
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Christopher T Whitlow
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | | | - Christina E Hugenschmidt
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Matthew Bobinski
- Department of Radiology, University of California, Davis, Davis, CA, United States
| | - Youngkyoo Jung
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, United States.,Department of Radiology, University of California, Davis, Davis, CA, United States.,Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States
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7
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Catchlove SJ, Parrish TB, Chen Y, Macpherson H, Hughes ME, Pipingas A. Regional Cerebrovascular Reactivity and Cognitive Performance in Healthy Aging. J Exp Neurosci 2018; 12:1179069518785151. [PMID: 30013388 PMCID: PMC6043917 DOI: 10.1177/1179069518785151] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 06/03/2018] [Indexed: 12/21/2022] Open
Abstract
Cerebrovascular reactivity (CVR) reflects the response of brain blood vessels to vasoactive stimuli, such as neural activity. The current research assessed age-related changes in regional CVR to 5% CO2 inhalation in younger (n = 30, range: 21-45 years) and older (n = 29, range: 55-75 years) adults, and the contribution of regional CVR to cognitive performance using blood-oxygen-level dependent contrast imaging (BOLD) functional magnetic resonance imaging (fMRI) at 3T field strength. CVR was measured by inducing hypercapnia using a block-design paradigm under physiological monitoring. Memory and attention were assessed with a comprehensive computerized aging battery. MRI data analysis was conducted using MATLAB® and SPM12. Memory and attention performance was positively associated with CVR in the temporal cortices. Temporal lobe CVR influenced memory performance independently of age, gender, and education level. When analyzing age groups separately, CVR in the hippocampus contributed significantly to memory score in the older group and was also related to subjective memory complaints. No associations between CVR and cognition were observed in younger adults. Vascular responsiveness in the brain has consequences for cognition in cognitively healthy people. These findings may inform other areas of research concerned with vaso-protective approaches for prevention or treatment of neurocognitive decline.
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Affiliation(s)
- Sarah J Catchlove
- Centre for Human Psychopharmacology,
Swinburne University, Hawthorn, VIC, Australia
| | - Todd B Parrish
- Feinberg School of Medicine,
Northwestern University, Chicago, IL, USA
| | - Yufen Chen
- Feinberg School of Medicine,
Northwestern University, Chicago, IL, USA
| | - Helen Macpherson
- Institute for Physical Activity and
Nutrition, Deakin University, Geelong, VIC, Australia
| | - Matthew E Hughes
- Centre for Mental Health, Swinburne
University, Hawthorn, VIC, Australia
- Australian National Imaging Facility, St
Lucia, QLD, Australia
| | - Andrew Pipingas
- Centre for Human Psychopharmacology,
Swinburne University, Hawthorn, VIC, Australia
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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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