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Schilling KG, Li M, Rheault F, Gao Y, Cai L, Zhao Y, Xu L, Ding Z, Anderson AW, Landman BA, Gore JC. Whole-brain, gray, and white matter time-locked functional signal changes with simple tasks and model-free analysis. Proc Natl Acad Sci U S A 2023; 120:e2219666120. [PMID: 37824529 PMCID: PMC10589709 DOI: 10.1073/pnas.2219666120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 08/11/2023] [Indexed: 10/14/2023] Open
Abstract
Recent studies have revealed the production of time-locked blood oxygenation level-dependent (BOLD) functional MRI (fMRI) signals throughout the entire brain in response to tasks, challenging the existence of sparse and localized brain functions and highlighting the pervasiveness of potential false negative fMRI findings. "Whole-brain" actually refers to gray matter, the only tissue traditionally studied with fMRI. However, several reports have demonstrated reliable detection of BOLD signals in white matter, which have previously been largely ignored. Using simple tasks and analyses, we demonstrate BOLD signal changes across the whole brain, in both white and gray matters, in similar manner to previous reports of whole brain studies. We investigated whether white matter displays time-locked BOLD signals across multiple structural pathways in response to a stimulus in a similar manner to the cortex. We find that both white and gray matter show time-locked activations across the whole brain, with a majority of both tissue types showing statistically significant signal changes for all task stimuli investigated. We observed a wide range of signal responses to tasks, with different regions showing different BOLD signal changes to the same task. Moreover, we find that each region may display different BOLD responses to different stimuli. Overall, we present compelling evidence that, just like all gray matter, essentially all white matter in the brain shows time-locked BOLD signal changes in response to multiple stimuli, challenging the idea of sparse functional localization and the prevailing wisdom of treating white matter BOLD signals as artifacts to be removed.
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Affiliation(s)
- Kurt G. Schilling
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37232
| | - Muwei Li
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37232
| | - Francois Rheault
- Department of Electrical Engineering and Computer Engineering, Vanderbilt University, Nashville, TN37235
| | - Yurui Gao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN37235
| | - Leon Cai
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN37235
| | - Yu Zhao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
| | - Lyuan Xu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
| | - Zhaohua Ding
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
| | - Adam W. Anderson
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37232
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN37235
| | - Bennett A. Landman
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
- Department of Electrical Engineering and Computer Engineering, Vanderbilt University, Nashville, TN37235
| | - John C. Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37232
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37232
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN37235
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Andrushko JW, Rinat S, Kirby ED, Dahlby J, Ekstrand C, Boyd LA. Females exhibit smaller volumes of brain activation and lower inter-subject variability during motor tasks. Sci Rep 2023; 13:17698. [PMID: 37848679 PMCID: PMC10582116 DOI: 10.1038/s41598-023-44871-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/12/2023] [Indexed: 10/19/2023] Open
Abstract
Past work has shown that brain structure and function differ between females and males. Males have larger cortical and sub-cortical volume and surface area (both total and subregional), while females have greater cortical thickness in most brain regions. Functional differences are also reported in the literature, yet to date little work has systematically considered whether patterns of brain activity indexed with functional magnetic resonance imaging (fMRI) differ between females and males. The current study sought to remediate this issue by employing task-based whole brain motor mapping analyses using an openly available dataset. We tested differences in patterns of functional brain activity associated with 12 voluntary movement patterns in females versus males. Results suggest that females exhibited smaller volumes of brain activation across all 12 movement tasks, and lower patterns of variability in 10 of the 12 movements. We also observed that females had greater cortical thickness, which is in alignment with previous analyses of structural differences. Overall, these findings provide a basis for considering biological sex in future fMRI research and provide a foundation of understanding differences in how neurological pathologies present in females vs males.
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Affiliation(s)
- Justin W Andrushko
- Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Shie Rinat
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Eric D Kirby
- Faculty of Individualized Interdisciplinary Studies, Simon Fraser University, Burnaby, BC, Canada
| | - Julia Dahlby
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Chelsea Ekstrand
- Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada.
| | - Lara A Boyd
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada.
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3
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Schilling KG, Li M, Rheault F, Gao Y, Cai L, Zhao Y, Xu L, Ding Z, Anderson AW, Landman BA, Gore JC. Whole-brain, gray and white matter time-locked functional signal changes with simple tasks and model-free analysis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528557. [PMID: 36824784 PMCID: PMC9948951 DOI: 10.1101/2023.02.14.528557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Recent studies have revealed the production of time-locked blood oxygenation-level dependent (BOLD) functional MRI (fMRI) signals throughout the entire brain in response to a task, challenging the idea of sparse and localized brain functions, and highlighting the pervasiveness of potential false negative fMRI findings. In these studies, 'whole-brain' refers to gray matter regions only, which is the only tissue traditionally studied with fMRI. However, recent reports have also demonstrated reliable detection and analyses of BOLD signals in white matter which have been largely ignored in previous reports. Here, using model-free analysis and simple tasks, we investigate BOLD signal changes in both white and gray matters. We aimed to evaluate whether white matter also displays time-locked BOLD signals across all structural pathways in response to a stimulus. We find that both white and gray matter show time-locked activations across the whole-brain, with a majority of both tissue types showing statistically significant signal changes for all task stimuli investigated. We observed a wide range of signal responses to tasks, with different regions showing very different BOLD signal changes to the same task. Moreover, we find that each region may display different BOLD responses to different stimuli. Overall, we present compelling evidence that the whole brain, including both white and gray matter, show time-locked activation to multiple stimuli, not only challenging the idea of sparse functional localization, but also the prevailing wisdom of treating white matter BOLD signals as artefacts to be removed.
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Affiliation(s)
- Kurt G Schilling
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Muwei Li
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Francois Rheault
- Department of Electrical Engineering and Computer Engineering, Vanderbilt University, Nashville, TN, USA
| | - Yurui Gao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Leon Cai
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Yu Zhao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Lyuan Xu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Zhaohua Ding
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Adam W Anderson
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Bennett A Landman
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Electrical Engineering and Computer Engineering, Vanderbilt University, Nashville, TN, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
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Tan SW, Cai GQ, Li QY, Guo Y, Pan YC, Zhang LJ, Ge QM, Shu HY, Zeng XJ, Shao Y. Altered Brain Activity in Strabismic Amblyopic Children as Determined by Regional Homogeneity: A Resting-State Functional Magnetic Resonance Imaging Study. Front Neurosci 2022; 16:879253. [PMID: 35720698 PMCID: PMC9201242 DOI: 10.3389/fnins.2022.879253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/13/2022] [Indexed: 11/22/2022] Open
Abstract
Objective Earlier research has determined that amblyopia or strabismus may cause remarkable brain anatomical and functional variations. Nonetheless, thus far, the spontaneous changes in brain activity in children with strabismus amblyopia (SA) remain unclear. The purpose of this study was to determine the association between abnormal brain activity in children with SA and its behavioral manifestations. Patients and Methods ?A total of 24 children with SA (10 male and 14 female children) as well as 24 healthy controls (HCs), including 10 male and 14 female children were closely matched in sex and age, and examined using resting-state functional magnetic resonance imaging (fMRI). The regional homogeneity (ReHo) technique was applied to evaluate spontaneous cerebral activity variations in children with SA and HCs. Moreover, associations between altered ReHo values in distinct cerebral areas and the degree of strabismus were assessed using Pearson correlation analysis. Results Remarkably increased ReHo values were observed in the right lingual, right superior frontal medial, bilateral superior parietal, and right inferior parietal gyri of children with SA compared with HCs. In contrast, mean ReHo values in children with SA were lower in the right cerebellum, left superior frontal gyrus, and left putamen nucleus. Furthermore, esotropia showed a positive correlation with ReHo values of the left putamen. Conclusion The anomalous spontaneous activity changes in several brain areas that are caused by SA may indicate neuropathologic mechanisms of visual deficits and oculomotor disorders in children with SA.
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Affiliation(s)
- Si-Wen Tan
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,The First Clinical Medical College, Nanchang University, Nanchang, China
| | - Guo-Qian Cai
- Department of Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qiu-Yu Li
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yu Guo
- Department of Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yi-Cong Pan
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Li-Juan Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qian-Min Ge
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Hui-Ye Shu
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xian-Jun Zeng
- Department of Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yi Shao
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
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5
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Genetic Alzheimer’s Disease Risk Affects the Neural Mechanisms of Pattern Separation in Hippocampal Subfields. Curr Biol 2020; 30:4201-4212.e3. [DOI: 10.1016/j.cub.2020.08.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/30/2020] [Accepted: 08/11/2020] [Indexed: 01/13/2023]
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6
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Grajauskas LA, Frizzell T, Song X, D'Arcy RCN. White Matter fMRI Activation Cannot Be Treated as a Nuisance Regressor: Overcoming a Historical Blind Spot. Front Neurosci 2019; 13:1024. [PMID: 31636527 PMCID: PMC6787144 DOI: 10.3389/fnins.2019.01024] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 09/09/2019] [Indexed: 12/19/2022] Open
Abstract
Despite past controversies, increasing evidence has led to acceptance that white matter activity is detectable using functional magnetic resonance imaging (fMRI). In spite of this, advanced analytic methods continue to be published that reinforce a historic bias against white matter activation by using it as a nuisance regressor. It is important that contemporary analyses overcome this blind spot in whole brain functional imaging, both to ensure that newly developed noise regression techniques are accurate, and to ensure that white matter, a vital and understudied part of the brain, is not ignored in functional neuroimaging studies.
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Affiliation(s)
- Lukas A Grajauskas
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,ImageTech Lab, Surrey Memorial Hospital, Fraser Health, Surrey, BC, Canada
| | - Tory Frizzell
- ImageTech Lab, Surrey Memorial Hospital, Fraser Health, Surrey, BC, Canada.,Faculty of Applied Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Xiaowei Song
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,ImageTech Lab, Surrey Memorial Hospital, Fraser Health, Surrey, BC, Canada
| | - Ryan C N D'Arcy
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.,ImageTech Lab, Surrey Memorial Hospital, Fraser Health, Surrey, BC, Canada.,Faculty of Applied Sciences, Simon Fraser University, Burnaby, BC, Canada.,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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7
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Reliability of the depth-dependent high-resolution BOLD hemodynamic response in human visual cortex and vicinity. Magn Reson Imaging 2017; 39:53-63. [PMID: 28137626 DOI: 10.1016/j.mri.2017.01.019] [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: 08/08/2016] [Revised: 01/26/2017] [Accepted: 01/26/2017] [Indexed: 02/06/2023]
Abstract
Functional magnetic resonance imaging (fMRI) often relies on a hemodynamic response function (HRF), the stereotypical blood oxygen level dependent (BOLD) response elicited by a brief (<4s) stimulus. Early measurements of the HRF used coarse spatial resolutions (≥3mm voxels) that would generally include contributions from white matter, gray matter, and the extra-pial compartment (the space between the pial surface and skull including pial blood vessels) within each voxel. To resolve these contributions, high-resolution fMRI (0.9-mm voxels) was performed at 3T in early visual cortex and its apposed white-matter and extra-pial compartments. The results characterized the depth dependence of the HRF and its reliability during nine fMRI sessions. Significant HRFs were observed in white-matter and extra-pial compartments as well as in gray matter. White-matter HRFs were faster and weaker than in the gray matter, while extra-pial HRFs were comparatively slower and stronger. Depth trends of the HRF peak amplitude were stable throughout a broad depth range that included all three compartments for each session. Across sessions, however, the depth trend of HRF peak amplitudes was stable only in the white matter and deep-intermediate gray matter, while there were strong session-to-session variations in the superficial gray matter and the extra-pial compartment. Thus, high-resolution fMRI can resolve significant and dynamically distinct HRFs in gray matter, white matter, and extra-pial compartments.
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8
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Cooper CM, Briggs RW, Farris EA, Bartlett J, Haley RW, Odegard TN. Memory and functional brain differences in a national sample of U.S. veterans with Gulf War Illness. Psychiatry Res Neuroimaging 2016; 250:33-41. [PMID: 27017423 DOI: 10.1016/j.pscychresns.2016.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 01/29/2016] [Accepted: 03/12/2016] [Indexed: 01/07/2023]
Abstract
Roughly 26-32% of U. S. veterans who served in the 1991 Persian Gulf War report suffering from chronic health problems. Memory complaints are regularly reported by ill Gulf War veterans (GWV), but limited data verify their complaints. This study investigated episodic memory and brain function in a nationally representative sample of GWV, using a face-name memory task and functional magnetic resonance imaging during encoding. A syndrome classification system was used to subdivide ill GWV into the three major Gulf War Illness syndrome types, "impaired cognition" (GWV-1), "confusion ataxia" (GWV-2), and "central pain" (GWV-3). Memory and brain function of ill GWV were contrasted to deployed and nondeployed well GWV controls (GWV-C). Ill GWV exhibited impaired memory function relative to GWV-C but the patterns of functional brain differences varied. Brain activation differentiated the GWV-C from the ill GWV. The different syndrome types also differed from one another in several brain regions. Additionally, the current study was the first to observe differences in brain function between deployed and nondeployed GWV-C. These results provide (1) evidence of memory impairment in ill GWV and differentiate the syndrome types at a functional neurobiological level, and (2) the role of deployment in the war on brain function.
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Affiliation(s)
- Crystal M Cooper
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Richard W Briggs
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, USA
| | - Emily A Farris
- Department of Psychology, University of Texas Permian Basin, Odessa, TX, USA
| | - James Bartlett
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Robert W Haley
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Timothy N Odegard
- Department of Psychology, Middle Tennessee State University, Murfreesboro, TN, USA
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9
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Gawryluk JR, Mazerolle EL, D'Arcy RCN. Does functional MRI detect activation in white matter? A review of emerging evidence, issues, and future directions. Front Neurosci 2014; 8:239. [PMID: 25152709 PMCID: PMC4125856 DOI: 10.3389/fnins.2014.00239] [Citation(s) in RCA: 159] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 07/21/2014] [Indexed: 12/13/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) is a non-invasive technique that allows for visualization of activated brain regions. Until recently, fMRI studies have focused on gray matter. There are two main reasons white matter fMRI remains controversial: (1) the blood oxygen level dependent (BOLD) fMRI signal depends on cerebral blood flow and volume, which are lower in white matter than gray matter and (2) fMRI signal has been associated with post-synaptic potentials (mainly localized in gray matter) as opposed to action potentials (the primary type of neural activity in white matter). Despite these observations, there is no direct evidence against measuring fMRI activation in white matter and reports of fMRI activation in white matter continue to increase. The questions underlying white matter fMRI activation are important. White matter fMRI activation has the potential to greatly expand the breadth of brain connectivity research, as well as improve the assessment and diagnosis of white matter and connectivity disorders. The current review provides an overview of the motivation to investigate white matter fMRI activation, as well as the published evidence of this phenomenon. We speculate on possible neurophysiologic bases of white matter fMRI signals, and discuss potential explanations for why reports of white matter fMRI activation are relatively scarce. We end with a discussion of future basic and clinical research directions in the study of white matter fMRI.
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Affiliation(s)
- Jodie R Gawryluk
- Division of Medical Sciences, Department of Psychology, University of Victoria Victoria, BC, Canada
| | - Erin L Mazerolle
- Department of Radiology, Faculty of Medicine, University of Calgary Calgary, AB, Canada
| | - Ryan C N D'Arcy
- Applied Sciences, Simon Fraser University Burnaby, BC, Canada ; Fraser Health Authority, Surrey Memorial Hospital Surrey, BC, Canada
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10
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Gawryluk JR, Mazerolle EL, Beyea SD, D'Arcy RCN. Functional MRI activation in white matter during the Symbol Digit Modalities Test. Front Hum Neurosci 2014; 8:589. [PMID: 25136311 PMCID: PMC4120763 DOI: 10.3389/fnhum.2014.00589] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/15/2014] [Indexed: 01/11/2023] Open
Abstract
Background: Recent evidence shows that functional magnetic resonance imaging (fMRI) can detect activation in white matter (WM). Such advances have important implications for understanding WM dysfunction. A key step in linking neuroimaging advances to the evaluation of clinical disorders is to examine whether WM activation can be detected at the individual level during clinical tests associated with WM function. We used an adapted Symbol Digit Modalities Test (SDMT) in a 4T fMRI study of healthy adults. Results: Results from 17 healthy individuals revealed WM activation in 88% of participants (15/17). The activation was in either the corpus callosum (anterior and/or posterior) or internal capsule (left and/or right). Conclusions: The findings link advances in fMRI to an established clinical test of WM function. Future work should focus on evaluating patients with WM dysfunction.
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Affiliation(s)
- Jodie R Gawryluk
- Department of Psychology/Neuroscience, University of Victoria Victoria, BC, Canada
| | - Erin L Mazerolle
- Faculty of Medicine, Department of Radiology, University of Calgary Calgary, AB, Canada
| | - Steven D Beyea
- Biomedical Translational Imaging Centre, IWK Health Centre Halifax, NS, Canada
| | - Ryan C N D'Arcy
- Applied Sciences, Simon Fraser University Burnaby, BC, Canada ; Fraser Health Authority, Surrey Memorial Hospital Surrey, BC, Canada
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11
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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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12
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Activation of auditory white matter tracts as revealed by functional magnetic resonance imaging. Neuroradiology 2014; 56:597-605. [PMID: 24736936 DOI: 10.1007/s00234-014-1362-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 03/31/2014] [Indexed: 02/06/2023]
Abstract
INTRODUCTION The ability of functional magnetic resonance imaging (fMRI) to detect activation in brain white matter (WM) is controversial. In particular, studies on the functional activation of WM tracts in the central auditory system are scarce. We utilized fMRI to assess and characterize the entire auditory WM pathway under robust experimental conditions involving the acquisition of a large number of functional volumes, the application of broadband auditory stimuli of high intensity, and the use of sparse temporal sampling to avoid scanner noise effects and increase signal-to-noise ratio. METHODS Nineteen healthy volunteers were subjected to broadband white noise in a block paradigm; each run had four sound-on/off alternations and was repeated nine times for each subject. Sparse sampling (TR=8 s) was used. RESULTS In addition to traditional gray matter (GM) auditory center activation, WM activation was detected in the isthmus and midbody of the corpus callosum (CC), tapetum, auditory radiation, lateral lemniscus, and decussation of the superior cerebellar peduncles. At the individual level, 13 of 19 subjects (68 %) had CC activation. Callosal WM exhibited a temporal delay of approximately 8 s in response to the stimulation compared with GM. CONCLUSIONS These findings suggest that direct evaluation of the entire functional network of the central auditory system may be possible using fMRI, which may aid in understanding the neurophysiological basis of the central auditory system and in developing treatment strategies for various central auditory disorders.
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13
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Mazerolle EL, Gawryluk JR, Dillen KNH, Patterson SA, Feindel KW, Beyea SD, Stevens MTR, Newman AJ, Schmidt MH, D’Arcy RC. Sensitivity to white matter FMRI activation increases with field strength. PLoS One 2013; 8:e58130. [PMID: 23483983 PMCID: PMC3587428 DOI: 10.1371/journal.pone.0058130] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 02/03/2013] [Indexed: 12/12/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) activation in white matter is controversial. Given that many of the studies that report fMRI activation in white matter used high field MRI systems, we investigated the field strength dependence of sensitivity to white matter fMRI activation. In addition, we evaluated the temporal signal to noise ratio (tSNR) of the different tissue types as a function of field strength. Data were acquired during a motor task (finger tapping) at 1.5 T and 4 T. Group and individual level activation results were considered in both the sensorimotor cortex and the posterior limb of the internal capsule. We found that sensitivity increases associated with field strength were greater for white matter than gray matter. The analysis of tSNR suggested that white matter might be less susceptible to increases in physiological noise related to increased field strength. We therefore conclude that high field MRI may be particularly advantageous for fMRI studies aimed at investigating activation in both gray and white matter.
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Affiliation(s)
- Erin L. Mazerolle
- Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada
- Department of Psychology & Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jodie R. Gawryluk
- Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada
- Department of Psychology & Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kim N. H. Dillen
- Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada
- Cognitive Neuroscience, Institute of Neuroscience and Medicine, Research Centre Juelich, Juelich, Germany
| | - Steven A. Patterson
- Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada
- Department of Physics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kirk W. Feindel
- Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Pediatric Neurology, IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Steven D. Beyea
- Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada
- Department of Physics, Dalhousie University, Halifax, Nova Scotia, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Radiology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - M. Tynan R Stevens
- Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada
- Department of Physics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Aaron J. Newman
- Department of Psychology & Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Ryan C.N. D’Arcy
- Institute for Biodiagnostics (Atlantic), National Research Council, Halifax, Nova Scotia, Canada
- Department of Psychology & Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Radiology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada
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14
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Cho YW, Song HJ, Lee JJ, Lee JH, Lee HJ, Yi SD, Chang HW, Berl MM, Gaillard WD, Chang Y. Age-related differences in the brain areas outside the classical language areas among adults using category decision task. BRAIN AND LANGUAGE 2012; 120:372-380. [PMID: 22305968 DOI: 10.1016/j.bandl.2011.12.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 10/24/2011] [Accepted: 12/24/2011] [Indexed: 05/31/2023]
Abstract
Older adults perform much like younger adults on language. This similar level of performance, however, may come about through different underlying brain processes. In the present study, we evaluated age-related differences in the brain areas outside the typical language areas among adults using a category decision task. Our results showed that similar activation patterns were found in classical language processing areas across the three age groups although regional lateralization indices in Broca's and Wernicke's areas decreased with age. The greatest differences, however, among the three groups were found primarily in the brain areas not associated with core language functioning including the hippocampus, middle frontal gyrus, ventromedial frontal cortex, medial superior parietal cortex and posterior cingulate cortex. Therefore, the non-classical language areas may exhibit an age-related difference between three age groups while the subjects show a similar activation pattern in the core, primary language processing during a semantic decision task.
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Affiliation(s)
- Yong Won Cho
- Department of Neurology, Keimyung University, Dongsan Medical Center, Daegu, Republic of Korea
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