1
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Shamir I, Assaf Y. Tutorial: a guide to diffusion MRI and structural connectomics. Nat Protoc 2024:10.1038/s41596-024-01052-5. [PMID: 39232202 DOI: 10.1038/s41596-024-01052-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/09/2024] [Indexed: 09/06/2024]
Abstract
Diffusion magnetic resonance imaging (dMRI) is a versatile imaging technique that has gained popularity thanks to its sensitive ability to measure displacement of water molecules within a living tissue on a micrometer scale. Although dMRI has been around since the early 1990s, its applications are constantly evolving, primarily regarding the inference of structural connectomics from nerve fiber trajectories. However, these applications require expertise in image processing and statistics, and it can be difficult for a newcomer to choose an appropriate pipeline to fit their research needs, not least because dMRI is such a flexible methodology that dozens of acquisition and analysis pipelines have been developed over the years. This introductory guide is designed for graduate students and researchers in the neuroscience community who are interested in integrating this new methodology regardless of their background in neuroimaging and computational tools. The guide provides a brief overview of the basic dMRI methodologies but focuses on its applications in neuroplasticity and connectomics. The guide starts with dMRI experimental designs and a complete step-by-step pipeline for structural connectomics. The following section covers the basics of dMRI, including parameters and clinical applications (apparent diffusion coefficient, mean diffusivity, fractional anisotropy and microscopic fractional anisotropy), as well as different approaches and models. The final section focuses on structural connectomics, covering subjects from fiber tracking (techniques, evaluation and limitations) to structural networks (constructing, analyzing and visualizing a network).
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Affiliation(s)
- Ittai Shamir
- Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Yaniv Assaf
- Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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2
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Oancea G, Manzone DM, Tremblay L. Short-Term Modulation of Online Monocular Visuomotor Function. J Mot Behav 2024:1-10. [PMID: 38275206 DOI: 10.1080/00222895.2024.2306322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 01/11/2024] [Indexed: 01/27/2024]
Abstract
Previous literature suggests that correcting ongoing movements is more effective when using the dominant limb and seeing with the dominant eye. Specifically, individuals are more effective at adjusting their movement to account for an imperceptibly perturbed or changed target location (i.e., online movement correction), when vision is available to the dominant eye. However, less is known if visual-motor functions based on monocular information can undergo short-term neuroplastic changes after a bout of practice, to improve online correction processes. Participants (n = 12) performed pointing movements monocularly and their ability to correct their movement towards an imperceptibly displaced target was assessed. On the first day, the eye associated with smaller correction amplitudes was exclusively trained during acquisition. While correction amplitude was assessed again with both eyes monocularly, only the eye with smaller correction amplitudes in the pre-test showed significant improvement in delayed retention. These results indicate that monocular visuomotor pathways can undergo short-term neuroplastic changes.
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Affiliation(s)
- Gabriela Oancea
- Perceptual Motor Behaviour Laboratory, Centre for Motor Control, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Damian M Manzone
- Perceptual Motor Behaviour Laboratory, Centre for Motor Control, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Luc Tremblay
- Perceptual Motor Behaviour Laboratory, Centre for Motor Control, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
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3
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Stee W, Legouhy A, Guerreri M, Villemonteix T, Zhang H, Peigneux P. Microstructural dynamics of motor learning and sleep-dependent consolidation: A diffusion imaging study. iScience 2023; 26:108426. [PMID: 38058306 PMCID: PMC10696465 DOI: 10.1016/j.isci.2023.108426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 09/20/2023] [Accepted: 11/08/2023] [Indexed: 12/08/2023] Open
Abstract
Memory consolidation can benefit from post-learning sleep, eventually leading to long-term microstructural brain modifications to accommodate new memory representations. Non-invasive diffusion-weighted magnetic resonance imaging (DWI) allows the observation of (micro)structural brain remodeling after time-limited motor learning. Here, we combine conventional diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) that allows modeling dendritic and axonal complexity in gray matter to investigate with improved specificity the microstructural brain mechanisms underlying time- and sleep-dependent motor memory consolidation dynamics. Sixty-one young healthy adults underwent four DWI sessions, two sequential motor trainings, and a night of total sleep deprivation or regular sleep distributed over five days. We observed rapid-motor-learning-related remodeling in occipitoparietal, temporal, and motor-related subcortical regions, reflecting temporary dynamics in learning-related neuronal brain plasticity processes. Sleep-related consolidation seems not to exert a detectable impact on diffusion parameters, at least on the timescale of a few days.
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Affiliation(s)
- Whitney Stee
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN – Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- GIGA - Cyclotron Research Centre - In Vivo Imaging, University of Liège (ULiège), Liège, Belgium
| | - Antoine Legouhy
- Department of Computer Science & Centre for Medical Image Computing, University College London (UCL), London, UK
| | - Michele Guerreri
- Department of Computer Science & Centre for Medical Image Computing, University College London (UCL), London, UK
| | - Thomas Villemonteix
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN – Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Laboratoire Psychopathologie et Processus de Changement, Paris-Lumières University, Saint-Denis, France
| | - Hui Zhang
- Department of Computer Science & Centre for Medical Image Computing, University College London (UCL), London, UK
| | - Philippe Peigneux
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN – Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- GIGA - Cyclotron Research Centre - In Vivo Imaging, University of Liège (ULiège), Liège, Belgium
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4
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Lehmann N, Aye N, Kaufmann J, Heinze HJ, Düzel E, Ziegler G, Taubert M. Changes in Cortical Microstructure of the Human Brain Resulting from Long-Term Motor Learning. J Neurosci 2023; 43:8637-8648. [PMID: 37875377 PMCID: PMC10727185 DOI: 10.1523/jneurosci.0537-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/08/2023] [Accepted: 09/04/2023] [Indexed: 10/26/2023] Open
Abstract
The mechanisms subserving motor skill acquisition and learning in the intact human brain are not fully understood. Previous studies in animals have demonstrated a causal relationship between motor learning and structural rearrangements of synaptic connections, raising the question of whether neurite-specific changes are also observable in humans. Here, we use advanced diffusion magnetic resonance imaging (MRI), sensitive to dendritic and axonal processes, to investigate neuroplasticity in response to long-term motor learning. We recruited healthy male and female human participants (age range 19-29) who learned a challenging dynamic balancing task (DBT) over four consecutive weeks. Diffusion MRI signals were fitted using Neurite Orientation Dispersion and Density Imaging (NODDI), a theory-driven biophysical model of diffusion, yielding measures of tissue volume, neurite density and the organizational complexity of neurites. While NODDI indices were unchanged and reliable during the control period, neurite orientation dispersion increased significantly during the learning period mainly in primary sensorimotor, prefrontal, premotor, supplementary, and cingulate motor areas. Importantly, reorganization of cortical microstructure during the learning phase predicted concurrent behavioral changes, whereas there was no relationship between microstructural changes during the control phase and learning. Changes in neurite complexity were independent of alterations in tissue density, cortical thickness, and intracortical myelin. Our results are in line with the notion that structural modulation of neurites is a key mechanism supporting complex motor learning in humans.SIGNIFICANCE STATEMENT The structural correlates of motor learning in the human brain are not fully understood. Results from animal studies suggest that synaptic remodeling (e.g., reorganization of dendritic spines) in sensorimotor-related brain areas is a crucial mechanism for the formation of motor memory. Using state-of-the-art diffusion magnetic resonance imaging (MRI), we found a behaviorally relevant increase in the organizational complexity of neocortical microstructure, mainly in primary sensorimotor, prefrontal, premotor, supplementary, and cingulate motor regions, following training of a challenging dynamic balancing task (DBT). Follow-up analyses suggested structural modulation of synapses as a plausible mechanism driving this increase, while colocalized changes in cortical thickness, tissue density, and intracortical myelin could not be detected. These results advance our knowledge about the neurobiological basis of motor learning in humans.
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Affiliation(s)
- Nico Lehmann
- Faculty of Human Sciences, Institute III, Department of Sport Science, Otto von Guericke University, Magdeburg 39104, Germany
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig 04103, Germany
| | - Norman Aye
- Faculty of Human Sciences, Institute III, Department of Sport Science, Otto von Guericke University, Magdeburg 39104, Germany
| | - Jörn Kaufmann
- Department of Neurology, Otto von Guericke University, Magdeburg 39120, Germany
| | - Hans-Jochen Heinze
- Department of Neurology, Otto von Guericke University, Magdeburg 39120, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg 39120, Germany
- Center for Behavioral and Brain Science (CBBS), Otto von Guericke University, Magdeburg 39106, Germany
- Leibniz-Institute for Neurobiology (LIN), Magdeburg 39118, Germany
| | - Emrah Düzel
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg 39120, Germany
- Center for Behavioral and Brain Science (CBBS), Otto von Guericke University, Magdeburg 39106, Germany
- Institute of Cognitive Neurology and Dementia Research, Otto von Guericke University, Magdeburg 39120, Germany
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, United Kingdom
| | - Gabriel Ziegler
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg 39120, Germany
- Institute of Cognitive Neurology and Dementia Research, Otto von Guericke University, Magdeburg 39120, Germany
| | - Marco Taubert
- Faculty of Human Sciences, Institute III, Department of Sport Science, Otto von Guericke University, Magdeburg 39104, Germany
- Center for Behavioral and Brain Science (CBBS), Otto von Guericke University, Magdeburg 39106, Germany
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5
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Minosse S, Picchi E, Conti A, di Giuliano F, di Ciò F, Sarmati L, Teti E, de Santis S, Andreoni M, Floris R, Guerrisi M, Garaci F, Toschi N. Multishell diffusion MRI reveals whole-brain white matter changes in HIV. Hum Brain Mapp 2023; 44:5113-5124. [PMID: 37647214 PMCID: PMC10502617 DOI: 10.1002/hbm.26448] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 07/15/2023] [Accepted: 07/26/2023] [Indexed: 09/01/2023] Open
Abstract
Diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) have been previously used to explore white matter related to human immunodeficiency virus (HIV) infection. While DTI and DKI suffer from low specificity, the Combined Hindered and Restricted Model of Diffusion (CHARMED) provides additional microstructural specificity. We used these three models to evaluate microstructural differences between 35 HIV-positive patients without neurological impairment and 20 healthy controls who underwent diffusion-weighted imaging using three b-values. While significant group effects were found in all diffusion metrics, CHARMED and DKI analyses uncovered wider involvement (80% vs. 20%) of all white matter tracts in HIV infection compared with DTI. In restricted fraction (FR) analysis, we found significant differences in the left corticospinal tract, middle cerebellar peduncle, right inferior cerebellar peduncle, right corticospinal tract, splenium of the corpus callosum, left superior cerebellar peduncle, left superior cerebellar peduncle, pontine crossing tract, left posterior limb of the internal capsule, and left/right medial lemniscus. These are involved in language, motor, equilibrium, behavior, and proprioception, supporting the functional integration that is frequently impaired in HIV-positivity. Additionally, we employed a machine learning algorithm (XGBoost) to discriminate HIV-positive patients from healthy controls using DTI and CHARMED metrics on an ROIwise basis, and unique contributions to this discrimination were examined using Shapley Explanation values. The CHARMED and DKI estimates produced the best performance. Our results suggest that biophysical multishell imaging, combining additional sensitivity and built-in specificity, provides further information about the brain microstructural changes in multimodal areas involved in attentive, emotional and memory networks often impaired in HIV patients.
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Affiliation(s)
- Silvia Minosse
- Diagnostic Imaging UnitUniversity Hospital Rome Tor VergataRomeItaly
| | - Eliseo Picchi
- Diagnostic Imaging UnitUniversity Hospital Rome Tor VergataRomeItaly
- Department of Biomedicine and PreventionUniversity of Rome Tor VergataRomeItaly
| | - Allegra Conti
- Department of Biomedicine and PreventionUniversity of Rome Tor VergataRomeItaly
| | - Francesca di Giuliano
- Department of Biomedicine and PreventionUniversity of Rome Tor VergataRomeItaly
- Neuroradiology UnitUniversity Hospital of Rome Tor VergataRomeItaly
| | - Francesco di Ciò
- Department of Biomedicine and PreventionUniversity of Rome Tor VergataRomeItaly
| | - Loredana Sarmati
- Clinical Infectious Diseases UnitUniversity Hospital of Rome Tor VergataRomeItaly
- Department of Systems MedicineUniversity of Rome Tor VergataRomeItaly
| | - Elisabetta Teti
- Clinical Infectious Diseases UnitUniversity Hospital of Rome Tor VergataRomeItaly
| | - Silvia de Santis
- Instituto de NeurocienciasConsejo Superior de Investigaciones Científicas and Universidad Miguel HernándezSant Joan d'AlacantSpain
| | - Massimo Andreoni
- Clinical Infectious Diseases UnitUniversity Hospital of Rome Tor VergataRomeItaly
- Department of Systems MedicineUniversity of Rome Tor VergataRomeItaly
| | - Roberto Floris
- Diagnostic Imaging UnitUniversity Hospital Rome Tor VergataRomeItaly
- Department of Biomedicine and PreventionUniversity of Rome Tor VergataRomeItaly
| | - Maria Guerrisi
- Department of Biomedicine and PreventionUniversity of Rome Tor VergataRomeItaly
| | - Francesco Garaci
- Department of Biomedicine and PreventionUniversity of Rome Tor VergataRomeItaly
- Neuroradiology UnitUniversity Hospital of Rome Tor VergataRomeItaly
- IRCSS San Raffaele CassinoFrosinoneItaly
| | - Nicola Toschi
- Neuroradiology UnitUniversity Hospital of Rome Tor VergataRomeItaly
- Athinoula A. Martinos Center for Biomedical ImagingHarvard Medical SchoolBostonMassachusettsUSA
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6
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Characterizing habit learning in the human brain at the individual and group levels: a multi-modal MRI study. Neuroimage 2023. [DOI: 10.1016/j.neuroimage.2023.120002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2023] Open
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7
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Villemonteix T, Guerreri M, Deantoni M, Balteau E, Schmidt C, Stee W, Zhang H, Peigneux P. Sleep-dependent structural neuroplasticity after a spatial navigation task: A diffusion imaging study. J Neurosci Res 2023; 101:1031-1043. [PMID: 36787426 DOI: 10.1002/jnr.25176] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/30/2022] [Accepted: 01/20/2023] [Indexed: 02/16/2023]
Abstract
Evidence for sleep-dependent changes in microstructural neuroplasticity remains scarce, despite the fact that it is a mandatory correlate of the reorganization of learning-related functional networks. We investigated the effects of post-training sleep on structural neuroplasticity markers measuring standard diffusion tensor imaging (DTI), mean diffusivity (MD), and the revised biophysical neurite orientation dispersion and density imaging (NODDI), free water fraction (FWF), and neurite density (NDI) parameters that enable disentangling whether MD changes result from modifications in neurites or in other cellular components (e.g., glial cells). Thirty-four healthy young adults were scanned using diffusion-weighted imaging (DWI) on Day1 before and after 40-min route learning (navigation) in a virtual environment, then were sleep deprived (SD) or slept normally (RS) for the night. After recovery sleep for 2 nights, they were scanned again (Day4) before and after 40-min route learning (navigation) in an extended environment. Sleep-related microstructural changes were computed on DTI (MD) and NODDI (NDI and FWF) parameters in the cortical ribbon and subcortical hippocampal and striatal regions of interest (ROIs). Results disclosed navigation learning-related decreased DWI parameters in the cortical ribbon (MD, FWF) and subcortical (MD, FWF, NDI) areas. Post-learning sleep-related changes were found at Day4 in the extended learning session (pre- to post-relearning percentage changes), suggesting a rapid sleep-related remodeling of neurites and glial cells subtending learning and memory processes in basal ganglia and hippocampal structures.
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Affiliation(s)
- Thomas Villemonteix
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN - Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Laboratoire Psychopathologie et Processus de Changement, EA2027, Paris 8 University, Saint-Denis, France
| | - Michele Guerreri
- Department of Computer Science & Centre for Medical Image Computing, University College London, London, UK
| | - Michele Deantoni
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN - Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| | - Evelyne Balteau
- Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| | - Christina Schmidt
- Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| | - Whitney Stee
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN - Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| | - Hui Zhang
- Department of Computer Science & Centre for Medical Image Computing, University College London, London, UK
| | - Philippe Peigneux
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN - Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
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8
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Changes in white matter microstructure and MRI-derived cerebral blood flow after 1-week of exercise training. Sci Rep 2021; 11:22061. [PMID: 34764358 PMCID: PMC8586229 DOI: 10.1038/s41598-021-01630-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 05/31/2021] [Indexed: 11/23/2022] Open
Abstract
Exercise is beneficial for brain health, inducing neuroplasticity and vascular plasticity in the hippocampus, which is possibly mediated by brain-derived neurotrophic factor (BDNF) levels. Here we investigated the short-term effects of exercise, to determine if a 1-week intervention is sufficient to induce brain changes. Fifteen healthy young males completed five supervised exercise training sessions over seven days. This was preceded and followed by a multi-modal magnetic resonance imaging (MRI) scan (diffusion-weighted MRI, perfusion-weighted MRI, dual-calibrated functional MRI) acquired 1 week apart, and blood sampling for BDNF. A diffusion tractography analysis showed, after exercise, a significant reduction relative to baseline in restricted fraction-an axon-specific metric-in the corpus callosum, uncinate fasciculus, and parahippocampal cingulum. A voxel-based approach found an increase in fractional anisotropy and reduction in radial diffusivity symmetrically, in voxels predominantly localised in the corpus callosum. A selective increase in hippocampal blood flow was found following exercise, with no change in vascular reactivity. BDNF levels were not altered. Thus, we demonstrate that 1 week of exercise is sufficient to induce microstructural and vascular brain changes on a group level, independent of BDNF, providing new insight into the temporal dynamics of plasticity, necessary to exploit the therapeutic potential of exercise.
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9
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Barrick EM, Thornton MA, Tamir DI. Mask exposure during COVID-19 changes emotional face processing. PLoS One 2021; 16:e0258470. [PMID: 34637454 PMCID: PMC8509869 DOI: 10.1371/journal.pone.0258470] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 09/28/2021] [Indexed: 11/19/2022] Open
Abstract
Faces are one of the key ways that we obtain social information about others. They allow people to identify individuals, understand conversational cues, and make judgements about others' mental states. When the COVID-19 pandemic hit the United States, widespread mask-wearing practices were implemented, causing a shift in the way Americans typically interact. This introduction of masks into social exchanges posed a potential challenge-how would people make these important inferences about others when a large source of information was no longer available? We conducted two studies that investigated the impact of mask exposure on emotion perception. In particular, we measured how participants used facial landmarks (visual cues) and the expressed valence and arousal (affective cues), to make similarity judgements about pairs of emotion faces. Study 1 found that in August 2020, participants with higher levels of mask exposure used cues from the eyes to a greater extent when judging emotion similarity than participants with less mask exposure. Study 2 measured participants' emotion perception in both April and September 2020 -before and after widespread mask adoption-in the same group of participants to examine changes in the use of facial cues over time. Results revealed an overall increase in the use of visual cues from April to September. Further, as mask exposure increased, people with the most social interaction showed the largest increase in the use of visual facial cues. These results provide evidence that a shift has occurred in how people process faces such that the more people are interacting with others that are wearing masks, the more they have learned to focus on visual cues from the eye area of the face.
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Affiliation(s)
- Elyssa M. Barrick
- Department of Psychology, Princeton University, Princeton, New Jersey, United States of America
| | - Mark A. Thornton
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Diana I. Tamir
- Department of Psychology, Princeton University, Princeton, New Jersey, United States of America
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10
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Gooijers J, De Luca A, Zivari Adab H, Leemans A, Roebroeck A, Swinnen SP. Indices of callosal axonal density and radius from diffusion MRI relate to upper and lower limb motor performance. Neuroimage 2021; 241:118433. [PMID: 34324975 DOI: 10.1016/j.neuroimage.2021.118433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/15/2021] [Accepted: 07/26/2021] [Indexed: 11/16/2022] Open
Abstract
Understanding the relationship between human brain structure and functional outcome is of critical importance in systems neuroscience. Diffusion MRI (dMRI) studies show that fractional anisotropy (FA) is predictive of motor control, underscoring the importance of white matter (WM). However, as FA is a surrogate marker of WM, we aim to shed new light on the structural underpinnings of this relationship by applying a multi-compartment microstructure model providing axonal density/radius indices. Sixteen young adults (7 males / 9 females), performed a hand/foot tapping task and a Multi Limb Reaction Time task. Furthermore, diffusion (STEAM &HARDI) and fMRI (localizer hand/foot activations) data were obtained. Sphere ROIs were placed on activation clusters with highest t value to guide interhemispheric WM tractography. Axonal radius/density indices of callosal parts intersecting with tractography were calculated from STEAM, using the diffusion-time dependent AxCaliber model, and correlated with behavior. Results indicated a possible association between larger apparent axonal radii of callosal motor fibers of the hand and higher tapping scores of both hands, and faster selection-related processing (normalized reaction) times (RTs) on diagonal limb combinations. Additionally, a trend was present for faster selection-related processing (normalized reaction) times for lower limbs being related with higher axonal density of callosal foot motor fibers, and for higher FA values of callosal motor fibers in general being related with better tapping and faster selection-related processing (normalized reaction) times. Whereas FA is sensitive in demonstrating associations with motor behavior, axon radius/density (i.e., fiber geometry) measures are promising to explain the physiological source behind the observed FA changes, contributing to deeper insights into brain-behavior interactions.
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Affiliation(s)
- J Gooijers
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium.
| | - A De Luca
- PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands; Neurology Department, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands
| | - H Zivari Adab
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium
| | - A Leemans
- PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands
| | - A Roebroeck
- Department of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht 6229 EV, Netherlands
| | - S P Swinnen
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium
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11
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Vukovic N, Hansen B, Lund TE, Jespersen S, Shtyrov Y. Rapid microstructural plasticity in the cortical semantic network following a short language learning session. PLoS Biol 2021; 19:e3001290. [PMID: 34125828 PMCID: PMC8202930 DOI: 10.1371/journal.pbio.3001290] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 05/17/2021] [Indexed: 01/22/2023] Open
Abstract
Despite the clear importance of language in our life, our vital ability to quickly and effectively learn new words and meanings is neurobiologically poorly understood. Conventional knowledge maintains that language learning—especially in adulthood—is slow and laborious. Furthermore, its structural basis remains unclear. Even though behavioural manifestations of learning are evident near instantly, previous neuroimaging work across a range of semantic categories has largely studied neural changes associated with months or years of practice. Here, we address rapid neuroanatomical plasticity accompanying new lexicon acquisition, specifically focussing on the learning of action-related language, which has been linked to the brain’s motor systems. Our results show that it is possible to measure and to externally modulate (using transcranial magnetic stimulation (TMS) of motor cortex) cortical microanatomic reorganisation after mere minutes of new word learning. Learning-induced microstructural changes, as measured by diffusion kurtosis imaging (DKI) and machine learning-based analysis, were evident in prefrontal, temporal, and parietal neocortical sites, likely reflecting integrative lexico-semantic processing and formation of new memory circuits immediately during the learning tasks. These results suggest a structural basis for the rapid neocortical word encoding mechanism and reveal the causally interactive relationship of modal and associative brain regions in supporting learning and word acquisition. This combined neuroimaging and brain stimulation study reveals rapid and distributed microstructural plasticity after a single immersive language learning session, demonstrating the causal relevance of the motor cortex in encoding the meaning of novel action words.
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Affiliation(s)
- Nikola Vukovic
- Department of Psychiatry, University of California San Francisco, San Francisco, United States of America
- * E-mail:
| | - Brian Hansen
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | | | - Sune Jespersen
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Yury Shtyrov
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Centre for Cognition and Decision making, HSE University, Moscow, Russia
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12
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Malovani C, Friedman N, Ben-Eliezer N, Tavor I. Tissue Probability Based Registration of Diffusion-Weighted Magnetic Resonance Imaging. J Magn Reson Imaging 2021; 54:1066-1076. [PMID: 33894095 DOI: 10.1002/jmri.27654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Current registration methods for diffusion-MRI (dMRI) data mostly focus on white matter (WM) areas. Recently, dMRI has been employed for the characterization of gray matter (GM) microstructure, emphasizing the need for registration methods that consider all tissue types. PURPOSE To develop a dMRI registration method based on GM, WM, and cerebrospinal fluid (CSF) tissue probability maps (TPMs). STUDY TYPE Retrospective longitudinal study. POPULATION Thirty-two healthy participants were scanned twice (legacy data), divided into a training-set (n = 16) and a test-set (n = 16), and 35 randomly-selected participants from the Human Connectome Project. FIELD STRENGTH/SEQUENCE 3.0T, diffusion-weighted spin-echo echo-planar sequence; T1-weighted spoiled gradient-recalled echo (SPGR) sequence. ASSESSMENT A joint segmentation-registration approach was implemented: Diffusion tensor imaging (DTI) maps were classified into TPMs using machine-learning approaches. The resulting GM, WM, and CSF probability maps were employed as features for image alignment. Validation was performed on the test dataset and the HCP dataset. Registration performance was compared with current mainstream registration tools. STATISTICAL TESTS Classifiers used for segmentation were evaluated using leave-one-out cross-validation and scored using Dice-index. Registration success was evaluated by voxel-wise variance, normalized cross-correlation of registered DTI maps, intra- and inter-subject similarity of the registered TPMs, and region-based intra-subject similarity using an anatomical atlas. One-way ANOVAs were performed to compare between our method and other registration tools. RESULTS The proposed method outperformed mainstream registration tools as indicated by lower voxel-wise variance of registered DTI maps (SD decrease of 10%) and higher similarity between registered TPMs within and across participants, for all tissue types (Dice increase of 0.1-0.2; P < 0.05). DATA CONCLUSION A joint segmentation-registration approach based on diffusion-driven TPMs provides a more accurate registration of dMRI data, outperforming other registration tools. Our method offers a "translation" of diffusion data into structural information in the form of TPMs, allowing to directly align diffusion and structural images. LEVEL OF EVIDENCE 1 Technical Efficacy Stage: 1.
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Affiliation(s)
- Cfir Malovani
- School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Naama Friedman
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Noam Ben-Eliezer
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Department of Bio-Medical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.,Center for Advanced Imaging Innovation and Research (CAI2R), New-York University Langone Medical Center, New York, New York, USA
| | - Ido Tavor
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Strauss Center for Computational Neuroimaging, Tel Aviv University, Tel Aviv, Israel
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13
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Dziemian S, Appenzeller S, von Bastian CC, Jäncke L, Langer N. Working Memory Training Effects on White Matter Integrity in Young and Older Adults. Front Hum Neurosci 2021; 15:605213. [PMID: 33935667 PMCID: PMC8079651 DOI: 10.3389/fnhum.2021.605213] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 03/15/2021] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES Working memory is essential for daily life skills like reading comprehension, reasoning, and problem-solving. Healthy aging of the brain goes along with working memory decline that can affect older people's independence in everyday life. Interventions in the form of cognitive training are a promising tool for delaying age-related working memory decline, yet the underlying structural plasticity of white matter is hardly studied. METHODS We conducted a longitudinal diffusion tensor imaging study to investigate the effects of an intensive four-week adaptive working memory training on white matter integrity quantified by global and tract-wise mean diffusivity. We compared diffusivity measures of fiber tracts that are associated with working memory of 32 young and 20 older participants that were randomly assigned to a working memory training group or an active control group. RESULTS The behavioral analysis showed an increase in working memory performance after the four-week adaptive working memory training. The neuroanatomical analysis revealed a decrease in mean diffusivity in the working memory training group after the training intervention in the right inferior longitudinal fasciculus for the older adults. There was also a decrease in mean diffusivity in the working memory training group in the right superior longitudinal fasciculus for the older and young participants after the intervention. CONCLUSION This study shows that older people can benefit from working memory training by improving their working memory performance that is also reflected in terms of improved white matter integrity in the superior longitudinal fasciculus and the inferior longitudinal fasciculus, where the first is an essential component of the frontoparietal network known to be essential in working memory.
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Affiliation(s)
- Sabine Dziemian
- Department of Methods of Plasticity Research, Institute of Psychology, University of Zurich, Zurich, Switzerland
- University Research Priority Program “Dynamic of Healthy Aging”, University of Zurich, Zurich, Switzerland
- Center for Reproducible Science, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), Zurich, Switzerland
| | - Sarah Appenzeller
- Department of Methods of Plasticity Research, Institute of Psychology, University of Zurich, Zurich, Switzerland
| | - Claudia C. von Bastian
- Department of Psychology, University of Sheffield, Sheffield, United Kingdom
- Neuroscience Institute, University of Sheffield, Sheffield, United Kingdom
| | - Lutz Jäncke
- Institute of Psychology, Department of Neuropsychology, University of Zurich, Zurich, Switzerland
- University Research Priority Program “Dynamic of Healthy Aging”, University of Zurich, Zurich, Switzerland
| | - Nicolas Langer
- Department of Methods of Plasticity Research, Institute of Psychology, University of Zurich, Zurich, Switzerland
- University Research Priority Program “Dynamic of Healthy Aging”, University of Zurich, Zurich, Switzerland
- Center for Reproducible Science, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), Zurich, Switzerland
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14
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Aloufi AE, Rowe FJ, Meyer GF. Behavioural performance improvement in visuomotor learning correlates with functional and microstructural brain changes. Neuroimage 2020; 227:117673. [PMID: 33359355 DOI: 10.1016/j.neuroimage.2020.117673] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 01/01/2023] Open
Abstract
A better understanding of practice-induced functional and structural changes in our brains can help us design more effective learning environments that provide better outcomes. Although there is growing evidence from human neuroimaging that experience-dependent brain plasticity is expressed in measurable brain changes that are correlated with behavioural performance, the relationship between behavioural performance and structural or functional brain changes, and particularly the time course of these changes, is not well characterised. To understand the link between neuroplastic changes and behavioural performance, 15 healthy participants in this study followed a systematic eye movement training programme for 30 min daily at home, 5 days a week and for 6 consecutive weeks. Behavioural performance statistics and eye tracking data were captured throughout the training period to evaluate learning outcomes. Imaging data (DTI and fMRI) were collected at baseline, after two and six weeks of continuous training, and four weeks after training ended. Participants showed significant improvements in behavioural performance (faster task completion time, lower fixation number and fixation duration). Spatially overlapping reductions in microstructural diffusivity measures (MD, AD and RD) and functional activation increases (BOLD signal) were observed in two main areas: extrastriate visual cortex (V3d) and the frontal part of the cerebellum/Fastigial Oculomotor Region (FOR), which are both involved in visual processing. An increase of functional activity was also recorded in the right frontal eye field. Behavioural, structural and functional changes were correlated. Microstructural change is a better predictor for long-term behavioural change than functional activation is, whereas the latter is superior in predicting instantaneous performance. Structural and functional measures at week 2 of the training programme also predict performance at week 6 and 10, which suggests that imaging data at an early stage of training may be useful in optimising practice environments or rehabilitative training programmes.
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Affiliation(s)
- A E Aloufi
- Department of Psychology, University of Liverpool, Eleanor Rathbone Building, Bedford Street South, Liverpool L69 7ZA, UK
| | - F J Rowe
- Institute of Population Health, University of Liverpool, Liverpool, UK
| | - G F Meyer
- Department of Psychology, University of Liverpool, Eleanor Rathbone Building, Bedford Street South, Liverpool L69 7ZA, UK.
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15
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A general role for ventral white matter pathways in morphological processing: Going beyond reading. Neuroimage 2020; 226:117577. [PMID: 33221439 DOI: 10.1016/j.neuroimage.2020.117577] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 10/13/2020] [Accepted: 11/11/2020] [Indexed: 11/23/2022] Open
Abstract
The ability to recognize the structural components of words, known as morphological processing, was recently associated with the bilateral ventral white matter pathways, across different writing systems. However, it remains unclear whether these associations are specific to the context of reading. To shed light on this question, in the current study we investigated whether the ventral pathways are associated with morphological processing in an oral word production task that does not involve reading. Forty-five participants completed a morpheme-based fluency task in Hebrew, as well as diffusion MRI (dMRI) scans. We used probabilistic tractography to segment the major ventral and dorsal white matter pathways, and assessed the correlations between their microstructural properties and performance on the morpheme-based fluency task. We found significant correlations between morpheme-based fluency and properties of the bilateral ventral tracts, suggesting that the involvement of these tracts in morphological processing extends beyond the reading modality. In addition, significant correlations were found in the frontal aslant tract (FAT), a dorsal tract associated with oral fluency and speech production. Together, our findings emphasize that neurocognitive associations reflect both the cognitive construct under investigation as well as the task used for its assessment. Lastly, to elucidate the biological factors underlying these correlations, we incorporated the composite hindered and restricted model of diffusion (CHARMED) framework, measured in independent scans. We found that only some of our findings could be attributed to variation in a CHARMED-based estimate of fiber density. Further, we were able to uncover additional correlations that could not be detected using traditional dMRI indices. In sum, our results show that the involvement of the ventral tracts in morphological processing extends to the production domain, and demonstrate the added value of including sensitive structural measurements in neurocognitive investigations.
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16
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Abstract
Recent evidence suggests that gains in performance observed while humans learn a novel motor sequence occur during the quiet rest periods interleaved with practice (micro-offline gains, MOGs). This phenomenon is reminiscent of memory replay observed in the hippocampus during spatial learning in rodents. Whether the hippocampus is also involved in the production of MOGs remains currently unknown. Using a multimodal approach in humans, here we show that activity in the hippocampus and the precuneus increases during the quiet rest periods and predicts the level of MOGs before asymptotic performance is achieved. These functional changes were followed by rapid alterations in brain microstructure in the order of minutes, suggesting that the same network that reactivates during the quiet periods of training undergoes structural plasticity. Our work points to the involvement of the hippocampal system in the reactivation of procedural memories.
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17
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Kristensen TD, Ebdrup BH, Hjorthøj C, Mandl RCW, Raghava JM, Jepsen JRM, Fagerlund B, Glenthøj LB, Wenneberg C, Krakauer K, Pantelis C, Glenthøj BY, Nordentoft M. No Effects of Cognitive Remediation on Cerebral White Matter in Individuals at Ultra-High Risk for Psychosis-A Randomized Clinical Trial. Front Psychiatry 2020; 11:873. [PMID: 33005161 PMCID: PMC7485415 DOI: 10.3389/fpsyt.2020.00873] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 08/10/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Individuals at ultra-high risk for psychosis (UHR) present with subtle alterations in cerebral white matter (WM), which appear to be associated with clinical and functional outcome. The effect of cognitive remediation on WM organization in UHR individuals has not been investigated previously. METHODS In a randomized, clinical trial, UHR individuals aged 18 to 40 years were assigned to treatment as usual (TAU) or TAU plus cognitive remediation for 20 weeks. Cognitive remediation comprised 20 x 2-h sessions of neurocognitive and social-cognitive training. Primary outcome was whole brain fractional anisotropy derived from diffusion weighted imaging, statistically tested as an interaction between timepoint and treatment group. Secondary outcomes were restricted to five predefined region of interest (ROI) analyses on fractional anisotropy, axial diffusivity, radial diffusivity and mean diffusivity. For significant timepoint and treatment group interactions within these five ROIs, we explored associations between longitudinal changes in WM and cognitive functions/clinical symptoms. Finally, we explored dose-response effects of cognitive remediation on WM. RESULTS A total of 111 UHR individuals were included. Attrition-rate was 26%. The cognitive remediation group completed on average 12 h of neurocognitive training, which was considerably lower than per protocol. We found no effect of cognitive remediation on whole-brain FA when compared to treatment as usual. Secondary ROI analyses revealed a nominal significant interaction between timepoint*treatment of AD in left medial lemniscus (P=0.016) which did not survive control for multiple comparisons. The exploratory test showed that this change in AD correlated to improvements of mental flexibility in the cognitive remediation group (p=0.001). We found no dose-response effect of neurocognitive training on WM. CONCLUSIONS Cognitive remediation comprising 12 h of neurocognitive training on average did not improve global or regional WM organization in UHR individuals. Further investigations of duration and intensity of cognitive training as necessary prerequisites of neuroplasticity-based changes are warranted. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, identifier NCT02098408.
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Affiliation(s)
- Tina D Kristensen
- Copenhagen Research Center for Mental Health, CORE, Mental Health Centre Copenhagen, University of Copenhagen, Hellerup, Denmark
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Bjørn H Ebdrup
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Melbourne Neuropsychiatry Center, Department of Psychiatry, The University of Melbourne, Melbourne, VIC, Australia
| | - Carsten Hjorthøj
- Copenhagen Research Center for Mental Health, CORE, Mental Health Centre Copenhagen, University of Copenhagen, Hellerup, Denmark
- Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - René C W Mandl
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
- Brain Center, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jayachandra M Raghava
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, University of Copenhagen, Glostrup, Denmark
| | - Jens Richardt M Jepsen
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
- Child and Adolescent Mental Health Centre, Mental Health Services, Capital Region of Denmark, University of Copenhagen, Hellerup, Denmark
| | - Birgitte Fagerlund
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
- Department of Psychology, Faculty of Social Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Louise B Glenthøj
- Copenhagen Research Center for Mental Health, CORE, Mental Health Centre Copenhagen, University of Copenhagen, Hellerup, Denmark
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Christina Wenneberg
- Copenhagen Research Center for Mental Health, CORE, Mental Health Centre Copenhagen, University of Copenhagen, Hellerup, Denmark
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Kristine Krakauer
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Christos Pantelis
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
- Melbourne Neuropsychiatry Center, Department of Psychiatry, The University of Melbourne, Melbourne, VIC, Australia
| | - Birte Y Glenthøj
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Merete Nordentoft
- Copenhagen Research Center for Mental Health, CORE, Mental Health Centre Copenhagen, University of Copenhagen, Hellerup, Denmark
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, CINS, and Center for Neuropsychiatric Schizophrenia Research, CNSR, Mental Health Centre Glostrup, University of Copenhagen, Glostrup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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18
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Pajkert A, Ploner CJ, Lehmann TN, Witte VA, Oltmanns F, Sommer W, Holtkamp M, Heekeren HR, Finke C. Early volumetric changes of hippocampus and medial prefrontal cortex following medial temporal lobe resection. Eur J Neurosci 2020; 52:4375-4384. [PMID: 32421911 DOI: 10.1111/ejn.14784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/07/2020] [Accepted: 05/09/2020] [Indexed: 12/14/2022]
Abstract
Previous studies have shown that cognitive demands and physical exercise stimulate adult neurogenesis in the dentate gyrus and hippocampus. Recent observations in healthy humans and patients with mild cognitive impairment moreover suggest that training-induced increases in hippocampal volume may be associated with improved memory performance. The corresponding plasticity processes in hippocampal volume may occur on timescales of months to years. For patients with focal lesions in this region, previous functional imaging studies suggest that increased recruitment of the contralateral hippocampus and extratemporal regions may be an important part of the reorganization of episodic memory. However, it is currently unclear whether focal damage to the medial temporal lobe (MTL) induces gray matter (GM) volume changes in the intact contralateral hippocampus and in connected network regions on a shorter timescale. We therefore investigated whether unilateral resection of the MTL, including the hippocampus, induces measurable volumetric changes in the contralateral hippocampus and in the default mode network (DMN). We recruited 31 patients with unilateral left (N = 19) or right (N = 12) hippocampal sclerosis undergoing MTL resection for treatment of drug-resistant epilepsy. Structural MRI was acquired immediately before and 3 months after surgery. Longitudinal voxel-based morphometry (VBM) analysis revealed a significant increase of right hippocampal volume following resection of the left anterior MTL. Furthermore, this patient group showed GM volume increases in the DMN. These results demonstrate significant structural plasticity of the contralateral hippocampus, even in patients with a long-standing unilateral hippocampal dysfunction and structural reorganization processes extending to distant, but functionally connected brain regions.
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Affiliation(s)
- Anna Pajkert
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Christoph J Ploner
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | - Veronica A Witte
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | | | - Werner Sommer
- Institut für Psychologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Martin Holtkamp
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Epilepsy-Center Berlin-Brandenburg, Berlin, Germany
| | - Hauke R Heekeren
- Department of Education and Psychology, Freie Universität Berlin, Berlin, Germany.,Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, Berlin, Germany
| | - Carsten Finke
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Berlin School of Mind & Brain, Humboldt-Universität zu Berlin, Berlin, Germany
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19
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Abend R, Rosenfelder A, Shamai D, Pine DS, Tavor I, Assaf Y, Bar-Haim Y. “Does attention bias modification induce structural brain changes? A commentary on Abend et al. (2019)” – Response. Biol Psychol 2020; 152:107865. [DOI: 10.1016/j.biopsycho.2020.107865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Tavor I, Botvinik‐Nezer R, Bernstein‐Eliav M, Tsarfaty G, Assaf Y. Short-term plasticity following motor sequence learning revealed by diffusion magnetic resonance imaging. Hum Brain Mapp 2019; 41:442-452. [PMID: 31596547 PMCID: PMC7267908 DOI: 10.1002/hbm.24814] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 09/12/2019] [Accepted: 09/22/2019] [Indexed: 01/06/2023] Open
Abstract
Current noninvasive methods to detect structural plasticity in humans are mainly used to study long-term changes. Diffusion magnetic resonance imaging (MRI) was recently proposed as a novel approach to reveal gray matter changes following spatial navigation learning and object-location memory tasks. In the present work, we used diffusion MRI to investigate the short-term neuroplasticity that accompanies motor sequence learning. Following a 45-min training session in which participants learned to accurately play a short sequence on a piano keyboard, changes in diffusion properties were revealed mainly in motor system regions such as the premotor cortex and cerebellum. In a second learning session taking place immediately afterward, feedback was given on the timing of key pressing instead of accuracy, while participants continued to learn. This second session induced a different plasticity pattern, demonstrating the dynamic nature of learning-induced plasticity, formerly thought to require months of training in order to be detectable. These results provide us with an important reminder that the brain is an extremely dynamic structure. Furthermore, diffusion MRI offers a novel measure to follow tissue plasticity particularly over short timescales, allowing new insights into the dynamics of structural brain plasticity.
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Affiliation(s)
- Ido Tavor
- Department of Anatomy and Anthropology, Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
- Department of Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, Affiliated to the Sackler School of MedicineTel Aviv UniversityTel AvivIsrael
- Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
| | - Rotem Botvinik‐Nezer
- Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
- Department of Neurobiology, Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
| | - Michal Bernstein‐Eliav
- Department of Anatomy and Anthropology, Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
- Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
| | - Galia Tsarfaty
- Department of Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, Affiliated to the Sackler School of MedicineTel Aviv UniversityTel AvivIsrael
| | - Yaniv Assaf
- Sagol School of NeuroscienceTel Aviv UniversityTel AvivIsrael
- Department of Neurobiology, Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
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21
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Huang SY, Tian Q, Fan Q, Witzel T, Wichtmann B, McNab JA, Daniel Bireley J, Machado N, Klawiter EC, Mekkaoui C, Wald LL, Nummenmaa A. High-gradient diffusion MRI reveals distinct estimates of axon diameter index within different white matter tracts in the in vivo human brain. Brain Struct Funct 2019; 225:1277-1291. [PMID: 31563995 DOI: 10.1007/s00429-019-01961-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 09/19/2019] [Indexed: 12/01/2022]
Abstract
Axon diameter and density are important microstructural metrics that offer valuable insight into the structural organization of white matter throughout the human brain. We report the systematic acquisition and analysis of a comprehensive diffusion MRI data set acquired with 300 mT/m maximum gradient strength in a cohort of 20 healthy human subjects that yields distinct and consistent patterns of axon diameter index in white matter tracts of arbitrary orientation. We use a straightforward, previously validated approach to estimating indices of axon diameter and volume fraction that involves interpolating the diffusion signal perpendicular to the principal fiber orientation and fitting a three-compartment model of intra-axonal, extra-axonal and free water diffusion. The resultant maps confirm the presence of larger diameter indices in the body of corpus callosum compared to the genu and splenium, as previously reported, and show larger axon diameter index in the corticospinal tracts compared to adjacent white matter tracts such as the cingulum. An anterior-to-posterior gradient in axon diameter index is also observed, with smaller diameter indices in the frontal lobes and larger diameter indices in the parieto-occipital white matter. These observations are consistent with known trends from prior histologic studies in humans and non-human primates. Rather than serving as fully quantitative measures of axon diameter and density, our results may be considered as axon diameter- and volume fraction-weighted images that appear to be modulated by the underlying microstructure and may capture broad trends in axonal size and packing density, acknowledging that the precise origin of such modulation requires further investigation that will be facilitated by the availability of high gradient strengths for in vivo human imaging.
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Affiliation(s)
- Susie Y Huang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Qiyuan Tian
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Qiuyun Fan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Thomas Witzel
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Barbara Wichtmann
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jennifer A McNab
- Radiological Sciences Laboratory, Department of Radiology, Stanford University, Stanford, CA, USA
| | - J Daniel Bireley
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Natalya Machado
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Eric C Klawiter
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Choukri Mekkaoui
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Lawrence L Wald
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Aapo Nummenmaa
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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22
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Dillingham CM, Milczarek MM, Perry JC, Frost BE, Parker GD, Assaf Y, Sengpiel F, O'Mara SM, Vann SD. Mammillothalamic Disconnection Alters Hippocampocortical Oscillatory Activity and Microstructure: Implications for Diencephalic Amnesia. J Neurosci 2019; 39:6696-6713. [PMID: 31235646 PMCID: PMC6703878 DOI: 10.1523/jneurosci.0827-19.2019] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/08/2019] [Accepted: 06/10/2019] [Indexed: 01/13/2023] Open
Abstract
Diencephalic amnesia can be as debilitating as the more commonly known temporal lobe amnesia, yet the precise contribution of diencephalic structures to memory processes remains elusive. Across four cohorts of male rats, we used discrete lesions of the mammillothalamic tract to model aspects of diencephalic amnesia and assessed the impact of these lesions on multiple measures of activity and plasticity within the hippocampus and retrosplenial cortex. Lesions of the mammillothalamic tract had widespread indirect effects on hippocampocortical oscillatory activity within both theta and gamma bands. Both within-region oscillatory activity and cross-regional synchrony were altered. The network changes were state-dependent, displaying different profiles during locomotion and paradoxical sleep. Consistent with the associations between oscillatory activity and plasticity, complementary analyses using several convergent approaches revealed microstructural changes, which appeared to reflect a suppression of learning-induced plasticity in lesioned animals. Together, these combined findings suggest a mechanism by which damage to the medial diencephalon can impact upon learning and memory processes, highlighting an important role for the mammillary bodies in the coordination of hippocampocortical activity.SIGNIFICANCE STATEMENT Information flow within the Papez circuit is critical to memory. Damage to ascending mammillothalamic projections has consistently been linked to amnesia in humans and spatial memory deficits in animal models. Here we report on the changes in hippocampocortical oscillatory dynamics that result from chronic lesions of the mammillothalamic tract and demonstrate, for the first time, that the mammillary bodies, independently of the supramammillary region, contribute to frequency modulation of hippocampocortical theta oscillations. Consistent with the associations between oscillatory activity and plasticity, the lesions also result in a suppression of learning-induced plasticity. Together, these data support new functional models whereby mammillary bodies are important for coordinating hippocampocortical activity rather than simply being a relay of hippocampal information as previously assumed.
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Affiliation(s)
- Christopher M Dillingham
- School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Michal M Milczarek
- School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - James C Perry
- School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - Bethany E Frost
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Greg D Parker
- EMRIC, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Yaniv Assaf
- George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel 6997801, and
| | - Frank Sengpiel
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Shane M O'Mara
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Seralynne D Vann
- School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom,
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23
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Assaf Y. Imaging laminar structures in the gray matter with diffusion MRI. Neuroimage 2019; 197:677-688. [DOI: 10.1016/j.neuroimage.2017.12.096] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 12/15/2017] [Accepted: 12/30/2017] [Indexed: 01/08/2023] Open
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Abend R, Rosenfelder A, Shamai D, Pine DS, Tavor I, Assaf Y, Bar-Haim Y. Brain structure changes induced by attention bias modification training. Biol Psychol 2019; 146:107736. [PMID: 31352029 DOI: 10.1016/j.biopsycho.2019.107736] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 07/02/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023]
Abstract
Attention bias modification (ABM) therapy aims to reduce anxiety by changing threat-related attention patterns using computerized training tasks. We examined changes in brain microstructure following ABM training. Thirty-two participants were randomly assigned to one of two training conditions: active ABM training shifting attention away from threat or attention control training involving no attention modification. Participants completed six lab visits, including five training sessions and three diffusion tensor imaging scans: immediately before and after the first training session, and at the end of the training series. Indices of local and global changes in microstructure and connectivity were measured. Significant longitudinal differences in fractional anisotropy (FA) between the active and control training regimens occurred in inferior temporal cortex. Changes in FA occurred across groups within ventromedial prefrontal cortex and middle occipital gyrus. These results indicate specific effects of active ABM on brain structure. Such changes could relate to clinical effects of ABM.
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Affiliation(s)
- Rany Abend
- Section on Development and Affective Neuroscience, National Institute of Mental Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Ariel Rosenfelder
- School of Psychological Sciences, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel
| | - Dana Shamai
- School of Psychological Sciences, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel
| | - Daniel S Pine
- Section on Development and Affective Neuroscience, National Institute of Mental Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Ido Tavor
- Sagol School of Neuroscience, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel; Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel
| | - Yaniv Assaf
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel
| | - Yair Bar-Haim
- School of Psychological Sciences, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978, Israel
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Alexander DC, Dyrby TB, Nilsson M, Zhang H. Imaging brain microstructure with diffusion MRI: practicality and applications. NMR IN BIOMEDICINE 2019; 32:e3841. [PMID: 29193413 DOI: 10.1002/nbm.3841] [Citation(s) in RCA: 205] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 07/09/2017] [Accepted: 09/11/2017] [Indexed: 05/22/2023]
Abstract
This article gives an overview of microstructure imaging of the brain with diffusion MRI and reviews the state of the art. The microstructure-imaging paradigm aims to estimate and map microscopic properties of tissue using a model that links these properties to the voxel scale MR signal. Imaging techniques of this type are just starting to make the transition from the technical research domain to wide application in biomedical studies. We focus here on the practicalities of both implementing such techniques and using them in applications. Specifically, the article summarizes the relevant aspects of brain microanatomy and the range of diffusion-weighted MR measurements that provide sensitivity to them. It then reviews the evolution of mathematical and computational models that relate the diffusion MR signal to brain tissue microstructure, as well as the expanding areas of application. Next we focus on practicalities of designing a working microstructure imaging technique: model selection, experiment design, parameter estimation, validation, and the pipeline of development of this class of technique. The article concludes with some future perspectives on opportunities in this topic and expectations on how the field will evolve in the short-to-medium term.
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Affiliation(s)
- Daniel C Alexander
- Centre for Medical Image Computing (CMIC), Department of Computer Science, UCL (University College London), Gower Street, London, UK
| | - Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Markus Nilsson
- Clinical Sciences Lund, Department of Radiology, Lund University, Lund, Sweden
| | - Hui Zhang
- Centre for Medical Image Computing (CMIC), Department of Computer Science, UCL (University College London), Gower Street, London, UK
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26
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Converging measures of neural change at the microstructural, informational, and cortical network levels in the hippocampus during the learning of the structure of organic compounds. Brain Struct Funct 2019; 224:1345-1357. [DOI: 10.1007/s00429-019-01838-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 01/21/2019] [Indexed: 12/16/2022]
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Toschi N, De Santis S, Granberg T, Ouellette R, Treaba CA, Herranz E, Mainero C. Evidence for Progressive Microstructural Damage in Early Multiple Sclerosis by Multi-Shell Diffusion Magnetic Resonance Imaging. Neuroscience 2019; 403:27-34. [PMID: 30708049 DOI: 10.1016/j.neuroscience.2019.01.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 01/12/2019] [Accepted: 01/14/2019] [Indexed: 12/21/2022]
Abstract
In multiple sclerosis (MS), it would be of clinical value to be able to track the progression of axonal pathology, especially before the manifestation of clinical disability. However, non-invasive evaluation of short-term longitudinal progression of white matter integrity is challenging. This study aims at assessing longitudinal changes in the restricted (i.e. intracellular) diffusion signal fraction (FR) in early-stage MS by using ultra-high gradient strength multi-shell diffusion magnetic resonance imaging. In 11 early MS subjects (disease duration ≤5 years), FR was obtained at two timepoints (one year apart) through the Composite Hindered and Restricted Model of Diffusion, along with conventional Diffusion Tensor Imaging metrics. At follow-up, no statistically significant change was detected in clinical variables, while all imaging metrics showed statistically significant longitudinal changes (p < 0.01, corrected for multiple comparisons) in widespread regions in normal-appearing white matter (NAWM). The most extensive longitudinal changes were observed in FR, including areas known to include a large fraction of crossing fibers. Furthermore, FR was also the only metric showing significant longitudinal changes in lesions that were present at both time points (p = 0.007), with no significant differences found for conventional diffusion metrics. Finally, FR was the only diffusion metric (as compared to Diffusion Tensor Imaging) that revealed pre-lesional changes already present at baseline. Taken together, our data provide evidence for progressive microstructural damage in the NAWM of early MS cases detectable already at 1-year follow-up. Our study highlights the value of multi-shell diffusion imaging for sensitive tracking of disease evolution in MS before any clinical changes are observed. This article is part of a Special Issue entitled: SI: MRI and Neuroinflammation.
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Affiliation(s)
- Nicola Toschi
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA; Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
| | - Silvia De Santis
- Instituto de Neurociencias de Alicante (CSIC-UMH), San Juan de Alicante, Spain; Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff University, Cardiff, UK
| | - Tobias Granberg
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Radiology, Karolinska University Hospital, Stockholm, Sweden
| | - Russell Ouellette
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Constantina A Treaba
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Elena Herranz
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Caterina Mainero
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
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De Santis S, Granberg T, Ouellette R, Treaba CA, Herranz E, Mainero C, Toschi N. Early axonal damage in normal appearing white matter in multiple sclerosis: Novel insights from multi-shell diffusion MRI. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2017:3024-3027. [PMID: 29060535 DOI: 10.1109/embc.2017.8037494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Conventional diffusion-weighted MR imaging techniques provide limited specificity in disentangling disease-related microstructural alterations involving changes in both axonal density and myelination. By simultaneously probing multiple diffusion regimens, multi-shell diffusion MRI is capable of increasing specificity to different tissue sub-compartments and hence separate different contributions to changes in diffusion-weighted signal attenuation. Advanced multi-shell diffusion models impose significant requirements on the amount of diffusion weighting (i.e. gradient coil performance) and angular resolution (i.e. in-scanner subject time), which commonly limits their applicability in a clinical setting. In this paper, we apply a high-b-value, high angular resolution multi-shell diffusion MRI protocol to a population of early multiple sclerosis (MS) patients and healthy controls. Through the Composite Hindered and Restricted Model of Diffusion (CHARMED) model, we extract indices for axonal density as well as parameters sensitive to myelin. We demonstrate increased sensitivity to microstructural changes in normal appearing white matter and in lesions in MS as compared to traditional models like DTI. These changes appear to be predominantly in axonal density, pointing towards the existence of axonal damage mechanisms in early MS.
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29
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Kristensen TD, Mandl RC, Jepsen JR, Rostrup E, Glenthøj LB, Nordentoft M, Glenthøj BY, Ebdrup BH. Non-pharmacological modulation of cerebral white matter organization: A systematic review of non-psychiatric and psychiatric studies. Neurosci Biobehav Rev 2018; 88:84-97. [DOI: 10.1016/j.neubiorev.2018.03.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 03/11/2018] [Accepted: 03/12/2018] [Indexed: 10/17/2022]
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30
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Doyon J, Gabitov E, Vahdat S, Lungu O, Boutin A. Current issues related to motor sequence learning in humans. Curr Opin Behav Sci 2018. [DOI: 10.1016/j.cobeha.2017.11.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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31
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Hofstetter S, Assaf Y. The rapid development of structural plasticity through short water maze training: A DTI study. Neuroimage 2017; 155:202-208. [PMID: 28476661 DOI: 10.1016/j.neuroimage.2017.04.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/21/2017] [Accepted: 04/25/2017] [Indexed: 10/19/2022] Open
Abstract
Diffusion MRI is sensitive to the microstructure of tissue and allows the study of structural plasticity over short time scales of only hours. The initial temporal and spatial progression of this process, however, has yet to be elucidated. With the aim of examining early temporal progression of structural plasticity, we subjected rats to short training periods on a task in the Morris water maze (MWM), a paradigm previously shown to induce rapid changes in diffusion tensor imaging (DTI) indices. Two groups of rats were each divided into subgroups that consecutively completed 1, 2 or 3 sets of short trials (up to 60s) in the MWM. Each set comprised 4 trials (1 from each quadrant of the WMW), with a specific time interval between sets. To assess the effect of the duration of the task on the evolving changes in DTI indices, we allowed a rest of 45min between sets in one group of rats and a 2-h rest in the other. All rats were scanned with a DTI protocol before and 45min after their last trial. We found that a few minutes of training in a new task sufficed to generate changes in diffusion indices. The earliest changes in DTI (measured after one set of trials) progressed with further training (measured after two sets), but within a few more minutes (after three sets) they reached a plateau. Lengthening the duration of the overall task by prolonging the time interval between sessions did not alter this pattern of change, suggesting that at least within this short time scale such changes are task-dependent, but not time dependent. Our results demonstrate the progression of structural neuroplasticity at different stages of exposure to a novel experience, and show that DTI can be used to trace, in vivo, the localization of structural plasticity induced by training.
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Affiliation(s)
- Shir Hofstetter
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yaniv Assaf
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel; Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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32
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Metzler-Baddeley C, Foley S, de Santis S, Charron C, Hampshire A, Caeyenberghs K, Jones DK. Dynamics of White Matter Plasticity Underlying Working Memory Training: Multimodal Evidence from Diffusion MRI and Relaxometry. J Cogn Neurosci 2017; 29:1509-1520. [PMID: 28358656 PMCID: PMC5881889 DOI: 10.1162/jocn_a_01127] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Adaptive working memory (WM) training may lead to cognitive benefits that are associated with white matter plasticity in parietofrontal networks, but the underlying mechanisms remain poorly understood. We investigated white matter microstructural changes after adaptive WM training relative to a nonadaptive comparison group. Microstructural changes were studied in the superior longitudinal fasciculus, the main parietofrontal connection, and the cingulum bundle as a comparison pathway. MRI-based metrics were the myelin water fraction and longitudinal relaxation rate R1 from multicomponent relaxometry (captured with the mcDESPOT approach) as proxy metrics of myelin, the restricted volume fraction from the composite hindered and restricted model of diffusion as an estimate of axon morphology, and fractional anisotropy and radial diffusivity from diffusion tensor imaging. PCA was used for dimensionality reduction. Adaptive training was associated with benefits in a “WM capacity” component and increases in a microstructural component (increases in R1, restricted volume fraction, fractional anisotropy, and reduced radial diffusivity) that predominantly loaded on changes in the right dorsolateral superior longitudinal fasciculus and the left parahippocampal cingulum. In contrast, nonadaptive comparison activities were associated with the opposite pattern of reductions in WM capacity and microstructure. No group differences were observed for the myelin water fraction metric suggesting that R1 was a more sensitive “myelin” index. These results demonstrate task complexity and location-specific white matter microstructural changes that are consistent with tissue alterations underlying myelination in response to training.
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Affiliation(s)
| | - Sonya Foley
- Cardiff University, Brain Research Imaging Centre (CUBRIC)
| | | | - Cyril Charron
- Cardiff University, Brain Research Imaging Centre (CUBRIC)
| | | | | | - Derek K Jones
- Cardiff University, Brain Research Imaging Centre (CUBRIC).,Australian Catholic University
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33
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Sepehrband F, O'Brien K, Barth M. A time-efficient acquisition protocol for multipurpose diffusion-weighted microstructural imaging at 7 Tesla. Magn Reson Med 2017; 78:2170-2184. [PMID: 28191681 DOI: 10.1002/mrm.26608] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/21/2016] [Accepted: 12/22/2016] [Indexed: 12/11/2022]
Abstract
PURPOSE Several diffusion-weighted MRI techniques have been developed and validated during the past 2 decades. While offering various neuroanatomical inferences, these techniques differ in their proposed optimal acquisition design, preventing clinicians and researchers benefiting from all potential inference methods, particularly when limited time is available. This study reports an optimal design that enables for a time-efficient diffusion-weighted MRI acquisition scheme at 7 Tesla. The primary audience of this article is the typical end user, interested in diffusion-weighted microstructural imaging at 7 Tesla. METHODS We tested b-values in the range of 700 to 3000 s/mm2 with different number of angular diffusion-encoding samples, against a data-driven "gold standard." RESULTS The suggested design is a protocol with b-values of 1000 and 2500 s/mm2 , with 25 and 50 samples, uniformly distributed over two shells. We also report a range of protocols in which the results of fitting microstructural models to the diffusion-weighted data had high correlation with the gold standard. CONCLUSION We estimated minimum acquisition requirements that enable diffusion tensor imaging, higher angular resolution diffusion-weighted imaging, neurite orientation dispersion, and density imaging and white matter tract integrity across whole brain with isotropic resolution of 1.8 mm in less than 11 min. Magn Reson Med 78:2170-2184, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Farshid Sepehrband
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia.,Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, USA
| | - Kieran O'Brien
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia.,Siemens Healthcare Pty Ltd, Brisbane, Australia
| | - Markus Barth
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
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Van Ombergen A, Laureys S, Sunaert S, Tomilovskaya E, Parizel PM, Wuyts FL. Spaceflight-induced neuroplasticity in humans as measured by MRI: what do we know so far? NPJ Microgravity 2017. [PMID: 28649624 PMCID: PMC5445591 DOI: 10.1038/s41526-016-0010-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Space travel poses an enormous challenge on the human body; microgravity, ionizing radiation, absence of circadian rhythm, confinement and isolation are just some of the features associated with it. Obviously, all of the latter can have an impact on human physiology and even induce detrimental changes. Some organ systems have been studied thoroughly under space conditions, however, not much is known on the functional and morphological effects of spaceflight on the human central nervous system. Previous studies have already shown that central nervous system changes occur during and after spaceflight in the form of neurovestibular problems, alterations in cognitive function and sensory perception, cephalic fluid shifts and psychological disturbances. However, little is known about the underlying neural substrates. In this review, we discuss the current limited knowledge on neuroplastic changes in the human central nervous system associated with spaceflight (actual or simulated) as measured by magnetic resonance imaging-based techniques. Furthermore, we discuss these findings as well as their future perspectives, since this can encourage future research into this delicate and intriguing aspect of spaceflight. Currently, the literature suffers from heterogeneous experimental set-ups and therefore, the lack of comparability of findings among studies. However, the cerebellum, cortical sensorimotor and somatosensory areas and vestibular-related pathways seem to be involved across different studies, suggesting that these brain regions are most affected by (simulated) spaceflight. Extending this knowledge is crucial, especially with the eye on long-duration interplanetary missions (e.g. Mars) and space tourism.
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Affiliation(s)
- Angelique Van Ombergen
- Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), University of Antwerp, Groenenborgerlaan 171, Antwerp, 2020 Belgium.,Faculty of Medicine and Health Sciences, University of Antwerp, Universiteitsplein 1, Wilrijk (Antwerp), 2610 Belgium.,Faculty of Sciences, Department of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, Antwerp, 2020 Belgium
| | - Steven Laureys
- Coma Science Group, GIGA-Research & Neurology Department, University and University Hospital of Liège, Liège, Belgium
| | - Stefan Sunaert
- KU Leuven-University of Leuven, Department of Imaging & Pathology, Translational MRI, Leuven, Belgium
| | - Elena Tomilovskaya
- SSC RF-Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Paul M Parizel
- Department of Radiology, Antwerp University Hospital & University of Antwerp, Antwerp, Belgium
| | - Floris L Wuyts
- Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), University of Antwerp, Groenenborgerlaan 171, Antwerp, 2020 Belgium.,Faculty of Sciences, Department of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, Antwerp, 2020 Belgium
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35
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Age-related white-matter correlates of motor sequence learning and consolidation. Neurobiol Aging 2016; 48:13-22. [DOI: 10.1016/j.neurobiolaging.2016.08.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 07/22/2016] [Accepted: 08/09/2016] [Indexed: 01/28/2023]
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36
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Sarubbo S, De Benedictis A, Merler S, Mandonnet E, Barbareschi M, Dallabona M, Chioffi F, Duffau H. Structural and functional integration between dorsal and ventral language streams as revealed by blunt dissection and direct electrical stimulation. Hum Brain Mapp 2016; 37:3858-3872. [PMID: 27258125 PMCID: PMC6867442 DOI: 10.1002/hbm.23281] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 05/07/2016] [Accepted: 05/24/2016] [Indexed: 01/24/2023] Open
Abstract
The most accepted framework of language processing includes a dorsal phonological and a ventral semantic pathway, connecting a wide network of distributed cortical hubs. However, the cortico-subcortical connectivity and the reciprocal anatomical relationships of this dual-stream system are not completely clarified. We performed an original blunt microdissection of 10 hemispheres with the exposition of locoregional short fibers and six long-range fascicles involved in language elaboration. Special attention was addressed to the analysis of termination sites and anatomical relationships between long- and short-range fascicles. We correlated these anatomical findings with a topographical analysis of 93 functional responses located at the terminal sites of the language bundles, collected by direct electrical stimulation in 108 right-handers. The locations of phonological and semantic paraphasias, verbal apraxia, speech arrest, pure anomia, and alexia were statistically analyzed, and the respective barycenters were computed in the MNI space. We found that terminations of main language bundles and functional responses have a wider distribution in respect to the classical definition of language territories. Our analysis showed that dorsal and ventral streams have a similar anatomical layer organization. These pathways are parallel and relatively segregated over their subcortical course while their terminal fibers are strictly overlapped at the cortical level. Finally, the anatomical features of the U-fibers suggested a role of locoregional integration between the phonological, semantic, and executive subnetworks of language, in particular within the inferoventral frontal lobe and the temporoparietal junction, which revealed to be the main criss-cross regions between the dorsal and ventral pathways. Hum Brain Mapp 37:3858-3872, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Silvio Sarubbo
- Division of Neurosurgery, Department of Neurosciences, "S. Chiara" Hospital, Trento APSS - 9 Largo Medaglie D'Oro, Trento, 38122, Italy.
- Structural and Functional Connectivity Lab, Division of Neurosurgery, "S. Chiara" Hospital, Trento APSS - 9 Largo Medaglie D'Oro, Trento, 38122, Italy.
| | - Alessandro De Benedictis
- Department of Neuroscience and Neurorehabilitation, Neurosurgery Unit, Bambino Gesù Children's Hospital - IRCCS, 4 Piazza Sant'Onofrio, Roma, 00165, Italy
| | - Stefano Merler
- Bruno Kessler Foundation (FBK), 18 via Sommarive, Trento, 38123, Italy
| | - Emmanuel Mandonnet
- Department of Neurosurgery, Lariboisiere Hospital, 2 Rue Ambroise Pare, Paris, 75010, France
| | - Mattia Barbareschi
- Department of Histopathology, "S. Chiara" Hospital, Trento APSS - 9 Largo Medaglie D'Oro, Trento, 38122, Italy
| | - Monica Dallabona
- Division of Neurosurgery, Department of Neurosciences, "S. Chiara" Hospital, Trento APSS - 9 Largo Medaglie D'Oro, Trento, 38122, Italy
| | - Franco Chioffi
- Division of Neurosurgery, Department of Neurosciences, "S. Chiara" Hospital, Trento APSS - 9 Largo Medaglie D'Oro, Trento, 38122, Italy
- Structural and Functional Connectivity Lab, Division of Neurosurgery, "S. Chiara" Hospital, Trento APSS - 9 Largo Medaglie D'Oro, Trento, 38122, Italy
| | - Hugues Duffau
- Department of Neurosurgery, Hôpital Gui De Chauliac, Montpellier University Medical Center, 80 Av Augustin Fliche, Montpellier, 34295, France
- Institute for Neuroscience of Montpellier, INSERM U1051, Team "Plasticity of Central Nervous System, Stem Cells and Glial Tumors," Saint Eloi Hospital, Montpellier, France
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Gunbey HP, Bilgici MC, Aslan K, Has AC, Ogur MG, Alhan A, Incesu L. Structural brain alterations of Down's syndrome in early childhood evaluation by DTI and volumetric analyses. Eur Radiol 2016; 27:3013-3021. [PMID: 27798752 DOI: 10.1007/s00330-016-4626-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 08/26/2016] [Accepted: 09/29/2016] [Indexed: 01/31/2023]
Abstract
OBJECTIVES To provide an initial assessment of white matter (WM) integrity with diffusion tensor imaging (DTI) and the accompanying volumetric changes in WM and grey matter (GM) through volumetric analyses of young children with Down's syndrome (DS). METHODS Ten children with DS and eight healthy control subjects were included in the study. Tract-based spatial statistics (TBSS) were used in the DTI study for whole-brain voxelwise analysis of fractional anisotropy (FA) and mean diffusivity (MD) of WM. Volumetric analyses were performed with an automated segmentation method to obtain regional measurements of cortical volumes. RESULTS Children with DS showed significantly reduced FA in association tracts of the fronto-temporo-occipital regions as well as the corpus callosum (CC) and anterior limb of the internal capsule (p < 0.05). Volumetric reductions included total cortical GM, cerebellar GM and WM volume, basal ganglia, thalamus, brainstem and CC in DS compared with controls (p < 0.05). CONCLUSION These preliminary results suggest that DTI and volumetric analyses may reflect the earliest complementary changes of the neurodevelopmental delay in children with DS and can serve as surrogate biomarkers of the specific elements of WM and GM integrity for cognitive development. KEY POINTS • DS is the most common genetic cause of intellectual disability. • WM and GM structural alterations represent the neurological features of DS. • DTI may identify the earliest aging process changes. • DTI-volumetric analyses can serve as surrogate biomarkers of neurodevelopment in DS.
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Affiliation(s)
- Hediye Pınar Gunbey
- Faculty of Medicine, Department of Radiology, Ondokuz Mayıs University, Neuroradiology Section, 55139, Kurupelit, Samsun, Turkey.
| | - Meltem Ceyhan Bilgici
- Faculty of Medicine, Department of Radiology, Ondokuz Mayıs University, Neuroradiology Section, 55139, Kurupelit, Samsun, Turkey
| | - Kerim Aslan
- Faculty of Medicine, Department of Radiology, Ondokuz Mayıs University, Neuroradiology Section, 55139, Kurupelit, Samsun, Turkey
| | - Arzu Ceylan Has
- National Magnetic Resonance Research Center, Bilkent University, Ankara, Turkey
| | | | - Aslıhan Alhan
- Department of Statistics, Ufuk University, Ankara, Turkey
| | - Lutfi Incesu
- Faculty of Medicine, Department of Radiology, Ondokuz Mayıs University, Neuroradiology Section, 55139, Kurupelit, Samsun, Turkey
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Vandermosten M, Price CJ, Golestani N. Plasticity of white matter connectivity in phonetics experts. Brain Struct Funct 2016; 221:3825-33. [PMID: 26386692 PMCID: PMC5009160 DOI: 10.1007/s00429-015-1114-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 08/27/2015] [Indexed: 11/03/2022]
Abstract
Phonetics experts are highly trained to analyze and transcribe speech, both with respect to faster changing, phonetic features, and to more slowly changing, prosodic features. Previously we reported that, compared to non-phoneticians, phoneticians had greater local brain volume in bilateral auditory cortices and the left pars opercularis of Broca's area, with training-related differences in the grey-matter volume of the left pars opercularis in the phoneticians group (Golestani et al. 2011). In the present study, we used diffusion MRI to examine white matter microstructure, indexed by fractional anisotropy, in (1) the long segment of arcuate fasciculus (AF_long), which is a well-known language tract that connects Broca's area, including left pars opercularis, to the temporal cortex, and in (2) the fibers arising from the auditory cortices. Most of these auditory fibers belong to three validated language tracts, namely to the AF_long, the posterior segment of the arcuate fasciculus and the middle longitudinal fasciculus. We found training-related differences in phoneticians in left AF_long, as well as group differences relative to non-experts in the auditory fibers (including the auditory fibers belonging to the left AF_long). Taken together, the results of both studies suggest that grey matter structural plasticity arising from phonetic transcription training in Broca's area is accompanied by changes to the white matter fibers connecting this very region to the temporal cortex. Our findings suggest expertise-related changes in white matter fibers connecting fronto-temporal functional hubs that are important for phonetic processing. Further studies can pursue this hypothesis by examining the dynamics of these expertise related grey and white matter changes as they arise during phonetic training.
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Affiliation(s)
| | - Cathy J Price
- Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, UK
| | - Narly Golestani
- Brain and Language Lab, Department of Clinical Neuroscience, Campus Biotech, University of Geneva, 9 Chemin des Mines, 1202, Geneva, Switzerland.
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39
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Thomas AG, Dennis A, Rawlings NB, Stagg CJ, Matthews L, Morris M, Kolind SH, Foxley S, Jenkinson M, Nichols TE, Dawes H, Bandettini PA, Johansen-Berg H. Multi-modal characterization of rapid anterior hippocampal volume increase associated with aerobic exercise. Neuroimage 2016; 131:162-70. [PMID: 26654786 PMCID: PMC4848119 DOI: 10.1016/j.neuroimage.2015.10.090] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 09/30/2015] [Accepted: 10/31/2015] [Indexed: 12/15/2022] Open
Abstract
The hippocampus has been shown to demonstrate a remarkable degree of plasticity in response to a variety of tasks and experiences. For example, the size of the human hippocampus has been shown to increase in response to aerobic exercise. However, it is currently unknown what underlies these changes. Here we scanned sedentary, young to middle-aged human adults before and after a six-week exercise intervention using nine different neuroimaging measures of brain structure, vasculature, and diffusion. We then tested two different hypotheses regarding the nature of the underlying changes in the tissue. Surprisingly, we found no evidence of a vascular change as has been previously reported. Rather, the pattern of changes is better explained by an increase in myelination. Finally, we show that hippocampal volume increase is temporary, returning to baseline after an additional six weeks without aerobic exercise. This is the first demonstration of a change in hippocampal volume in early to middle adulthood suggesting that hippocampal volume is modulated by aerobic exercise throughout the lifespan rather than only in the presence of age related atrophy. It is also the first demonstration of hippocampal volume change over a period of only six weeks, suggesting that gross morphometric hippocampal plasticity occurs faster than previously thought.
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Affiliation(s)
- Adam G Thomas
- Section on Functional Imaging Methods, NIMH, NIH, DHHS, Bethesda, MD, USA; FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
| | - Andrea Dennis
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Nancy B Rawlings
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Charlotte J Stagg
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Lucy Matthews
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Martyn Morris
- Movement Sciences Group, Oxford Brookes University, Oxford, United Kingdom
| | - Shannon H Kolind
- Center for Neuroimaging Sciences, King's College London, London, ON, Canada
| | - Sean Foxley
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Mark Jenkinson
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Thomas E Nichols
- Department of Statistics, University of Warwick, Coventry, United Kingdom
| | - Helen Dawes
- Department of Statistics, University of Warwick, Coventry, United Kingdom
| | - Peter A Bandettini
- Section on Functional Imaging Methods, NIMH, NIH, DHHS, Bethesda, MD, USA
| | - Heidi Johansen-Berg
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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40
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Abstract
Progress in magnetic resonance imaging (MRI) now makes it possible to identify the major white matter tracts in the living human brain. These tracts are important because they carry many of the signals communicated between different brain regions. MRI methods coupled with biophysical modeling can measure the tissue properties and structural features of the tracts that impact our ability to think, feel, and perceive. This review describes the fundamental ideas of the MRI methods used to identify the major white matter tracts in the living human brain.
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Affiliation(s)
- Brian A Wandell
- Department of Psychology and Stanford Neurosciences Institute, Stanford University, Stanford, California 94305;
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41
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Taubert M, Mehnert J, Pleger B, Villringer A. Rapid and specific gray matter changes in M1 induced by balance training. Neuroimage 2016; 133:399-407. [PMID: 26994831 DOI: 10.1016/j.neuroimage.2016.03.017] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 02/19/2016] [Accepted: 03/07/2016] [Indexed: 02/08/2023] Open
Abstract
Training-induced changes in cortical structure can be observed non-invasively with magnetic resonance imaging (MRI). While macroscopic changes were found mainly after weeks to several months of training in humans, imaging of motor cortical networks in animals revealed rapid microstructural alterations after a few hours of training. We used MRI to test the hypothesis of immediate and specific training-induced alterations in motor cortical gray matter in humans. We found localized increases in motor cortical thickness after 1h of practice in a complex balancing task. These changes were specific to motor cortical effector representations primarily responsible for balance control in our task (lower limb and trunk) and these effects could be confirmed in a replication study. Cortical thickness changes (i) linearly increased across the training session, (ii) occurred independent of alterations in resting cerebral blood flow and (iii) were not triggered by repetitive use of the lower limbs. Our findings show that motor learning triggers rapid and specific gray matter changes in M1.
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Affiliation(s)
- Marco Taubert
- Department of Neurology, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
| | - Jan Mehnert
- Department of Neurology, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Department of Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany
| | - Burkhard Pleger
- Department of Neurology, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Department of Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany
| | - Arno Villringer
- Department of Neurology, Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Department of Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany; Mind and Brain Institute at Berlin School of Mind and Brain, Charite´ and Humboldt University, Berlin, Germany
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42
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De Santis S, Jones DK, Roebroeck A. Including diffusion time dependence in the extra-axonal space improves in vivo estimates of axonal diameter and density in human white matter. Neuroimage 2016; 130:91-103. [PMID: 26826514 PMCID: PMC4819719 DOI: 10.1016/j.neuroimage.2016.01.047] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 01/14/2016] [Accepted: 01/20/2016] [Indexed: 12/01/2022] Open
Abstract
Axonal density and diameter are two fundamental properties of brain white matter. Recently, advanced diffusion MRI techniques have made these two parameters accessible in vivo. However, the techniques available to estimate such parameters are still under development. For example, current methods to map axonal diameters capture relative trends over different structures, but consistently over-estimate absolute diameters. Axonal density estimates are more accessible experimentally, but different modeling approaches exist and the impact of the experimental parameters has not been thoroughly quantified, potentially leading to incompatibility of results obtained in different studies using different techniques. Here, we characterise the impact of diffusion time on axonal density and diameter estimates using Monte Carlo simulations and STEAM diffusion MRI at 7 T on 9 healthy volunteers. We show that axonal density and diameter estimates strongly depend on diffusion time, with diameters almost invariably overestimated and density both over and underestimated for some commonly used models. Crucially, we also demonstrate that these biases are reduced when the model accounts for diffusion time dependency in the extra-axonal space. For axonal density estimates, both upward and downward bias in different situations are removed by modeling extra-axonal time-dependence, showing increased accuracy in these estimates. For axonal diameter estimates, we report increased accuracy in ground truth simulations and axonal diameter estimates decreased away from high values given by earlier models and towards known values in the human corpus callosum when modeling extra-axonal time-dependence. Axonal diameter feasibility under both advanced and clinical settings is discussed in the light of the proposed advances.
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Affiliation(s)
- Silvia De Santis
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - Derek K Jones
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK
| | - Alard Roebroeck
- Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands
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43
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Bernardi G, Cecchetti L, Siclari F, Buchmann A, Yu X, Handjaras G, Bellesi M, Ricciardi E, Kecskemeti SR, Riedner BA, Alexander AL, Benca RM, Ghilardi MF, Pietrini P, Cirelli C, Tononi G. Sleep reverts changes in human gray and white matter caused by wake-dependent training. Neuroimage 2016; 129:367-377. [PMID: 26812659 DOI: 10.1016/j.neuroimage.2016.01.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 01/08/2016] [Accepted: 01/09/2016] [Indexed: 01/25/2023] Open
Abstract
Learning leads to rapid microstructural changes in gray (GM) and white (WM) matter. Do these changes continue to accumulate if task training continues, and can they be reverted by sleep? We addressed these questions by combining structural and diffusion weighted MRI and high-density EEG in 16 subjects studied during the physiological sleep/wake cycle, after 12 h and 24 h of intense practice in two different tasks, and after post-training sleep. Compared to baseline wake, 12 h of training led to a decline in cortical mean diffusivity. The decrease became even more significant after 24 h of task practice combined with sleep deprivation. Prolonged practice also resulted in decreased ventricular volume and increased GM and WM subcortical volumes. All changes reverted after recovery sleep. Moreover, these structural alterations predicted cognitive performance at the individual level, suggesting that sleep's ability to counteract performance deficits is linked to its effects on the brain microstructure. The cellular mechanisms that account for the structural effects of sleep are unknown, but they may be linked to its role in promoting the production of cerebrospinal fluid and the decrease in synapse size and strength, as well as to its recently discovered ability to enhance the extracellular space and the clearance of brain metabolites.
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Affiliation(s)
- Giulio Bernardi
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA; Laboratory of Clinical Biochemistry and Molecular Biology, University of Pisa, Pisa 56126, Italy; Clinical Psychology Branch, University of Pisa, AOUP Santa Chiara, Pisa 56126, Italy
| | - Luca Cecchetti
- Laboratory of Clinical Biochemistry and Molecular Biology, University of Pisa, Pisa 56126, Italy; Clinical Psychology Branch, University of Pisa, AOUP Santa Chiara, Pisa 56126, Italy
| | - Francesca Siclari
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA
| | - Andreas Buchmann
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA
| | - Xiaoqian Yu
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA
| | - Giacomo Handjaras
- Laboratory of Clinical Biochemistry and Molecular Biology, University of Pisa, Pisa 56126, Italy; Clinical Psychology Branch, University of Pisa, AOUP Santa Chiara, Pisa 56126, Italy
| | - Michele Bellesi
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA
| | - Emiliano Ricciardi
- Laboratory of Clinical Biochemistry and Molecular Biology, University of Pisa, Pisa 56126, Italy; Clinical Psychology Branch, University of Pisa, AOUP Santa Chiara, Pisa 56126, Italy
| | - Steven R Kecskemeti
- Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin, Madison, WI 53705, USA
| | - Brady A Riedner
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA
| | - Andrew L Alexander
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA; Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin, Madison, WI 53705, USA; Dept. of Medical Physics, University of Wisconsin, Madison, WI 53705, USA
| | - Ruth M Benca
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA
| | - M Felice Ghilardi
- Dept. of Physiology and Pharmacology, City University of New York Medical School, New York, NY 10031, USA
| | - Pietro Pietrini
- Laboratory of Clinical Biochemistry and Molecular Biology, University of Pisa, Pisa 56126, Italy; Clinical Psychology Branch, University of Pisa, AOUP Santa Chiara, Pisa 56126, Italy; IMT School for Advanced Studies Lucca, Lucca 55100, Italy.
| | - Chiara Cirelli
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA.
| | - Giulio Tononi
- Dept. of Psychiatry, University of Wisconsin, Madison, WI 53719, USA.
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44
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Keller TA, Just MA. Structural and functional neuroplasticity in human learning of spatial routes. Neuroimage 2016; 125:256-266. [DOI: 10.1016/j.neuroimage.2015.10.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/30/2015] [Accepted: 10/06/2015] [Indexed: 12/18/2022] Open
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45
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Winston GP. The potential role of novel diffusion imaging techniques in the understanding and treatment of epilepsy. Quant Imaging Med Surg 2015; 5:279-87. [PMID: 25853085 DOI: 10.3978/j.issn.2223-4292.2015.02.03] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 02/05/2015] [Indexed: 01/14/2023]
Abstract
Epilepsy is a common neurological disorder in which magnetic resonance imaging plays a key role. Diffusion imaging based on the molecular diffusion of water has been widely used clinically and in research for patients with epilepsy. Diffusion tensor imaging (DTI), the most common model, has been used for around two decades. Several parameters can be derived from DTI that are sensitive, but non-specific, to underlying structural changes. DTI assumes a single diffusion process following a Gaussian distribution within each voxel and is thus an overly simplistic representation of tissue microstructure. Several more advanced models of diffusion are now available that may have greater utility in the understanding of the effects of epilepsy on tissue microstructure. In this review, I summarise the principles, applications in epilepsy and future potential of three such techniques. Diffusion kurtosis imaging (DKI) characterises the degree to which diffusion deviates from Gaussian behaviour and gives an idea of the underlying tissue complexity. It has been used in both focal and generalised epilepsy and seems more sensitive than DTI. Multi-compartment models separate the signal from extra- and intra-axonal compartments in each voxel. The Composite Hindered and Restricted Model of Diffusion (CHARMED) can characterise axonal density but has not yet been applied in patients with epilepsy. The Neurite Orientation Dispersion and Density Imaging (NODDI) model can determine the intracellular volume fraction (ICVF) and degree of dispersion of neurite orientation. Preliminary data suggest it may more sensitive than conventional and diffusion imaging in localising focal epilepsy.
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Affiliation(s)
- Gavin P Winston
- 1 Epilepsy Society MRI Unit, Chesham Lane, Chalfont St Peter, Bucks SL9 0RJ, UK ; 2 Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
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46
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Krick CM, Grapp M, Daneshvar-Talebi J, Reith W, Plinkert PK, Bolay HV. Cortical reorganization in recent-onset tinnitus patients by the Heidelberg Model of Music Therapy. Front Neurosci 2015; 9:49. [PMID: 25745385 PMCID: PMC4333796 DOI: 10.3389/fnins.2015.00049] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 02/04/2015] [Indexed: 12/19/2022] Open
Abstract
Pathophysiology and treatment of tinnitus still are fields of intensive research. The neuroscientifically motivated Heidelberg Model of Music Therapy, previously developed by the German Center for Music Therapy Research, Heidelberg, Germany, was applied to explore its effects on individual distress and on brain structures. This therapy is a compact and fast application of nine consecutive 50-min sessions of individualized therapy implemented over 1 week. Clinical improvement and long-term effects over several years have previously been published. However, the underlying neural basis of the therapy's success has not yet been explored. In the current study, the therapy was applied to acute tinnitus patients (TG) and healthy active controls (AC). Non-treated patients were also included as passive controls (PTC). As predicted, the therapeutic intervention led to a significant decrease of tinnitus-related distress in TG compared to PTC. Before and after the study week, high-resolution MRT scans were obtained for each subject. Assessment by repeated measures design for several groups (Two-Way ANOVA) revealed structural gray matter (GM) increase in TG compared to PTC, comprising clusters in precuneus, medial superior frontal areas, and in the auditory cortex. This pattern was further applied as mask for general GM changes as induced by the therapy week. The therapy-like procedure in AC also elicited similar GM increases in precuneus and frontal regions. Comparison between structural effects in TG vs. AC was calculated within the mask for general GM changes to obtain specific effects in tinnitus patients, yielding GM increase in right Heschl's gyrus, right Rolandic operculum, and medial superior frontal regions. In line with recent findings on the crucial role of the auditory cortex in maintaining tinnitus-related distress, a causative relation between the therapy-related GM alterations in auditory areas and the long-lasting therapy effects can be assumed.
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Affiliation(s)
- Christoph M Krick
- Department for Neuroradiology, Saarland University Hospital Homburg, Germany
| | - Miriam Grapp
- German Center for Music Therapy Research (Victor Dulger Institute) DZM Heidelberg, Germany
| | | | - Wolfgang Reith
- Department for Neuroradiology, Saarland University Hospital Homburg, Germany
| | - Peter K Plinkert
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital for Ear, Nose, and Throat, University of Heidelberg Heidelberg, Germany
| | - Hans Volker Bolay
- Music Therapy Tinnitus Outpatient Department, German Center for Music Therapy Research (Victor Dulger Institute) DZM Heidelberg, Germany
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Fabri M, Pierpaoli C, Barbaresi P, Polonara G. Functional topography of the corpus callosum investigated by DTI and fMRI. World J Radiol 2014; 6:895-906. [PMID: 25550994 PMCID: PMC4278150 DOI: 10.4329/wjr.v6.i12.895] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 09/02/2014] [Accepted: 10/29/2014] [Indexed: 02/06/2023] Open
Abstract
This short review examines the most recent functional studies of the topographic organization of the human corpus callosum, the main interhemispheric commissure. After a brief description of its anatomy, development, microstructure, and function, it examines and discusses the latest findings obtained using diffusion tensor imaging (DTI) and tractography (DTT) and functional magnetic resonance imaging (fMRI), three recently developed imaging techniques that have significantly expanded and refined our knowledge of the commissure. While DTI and DTT have been providing insights into its microstructure, integrity and level of myelination, fMRI has been the key technique in documenting the activation of white matter fibers, particularly in the corpus callosum. By combining DTT and fMRI it has been possible to describe the trajectory of the callosal fibers interconnecting the primary olfactory, gustatory, motor, somatic sensory, auditory and visual cortices at sites where the activation elicited by peripheral stimulation was detected by fMRI. These studies have demonstrated the presence of callosal fiber tracts that cross the commissure at the level of the genu, body, and splenium, at sites showing fMRI activation. Altogether such findings lend further support to the notion that the corpus callosum displays a functional topographic organization that can be explored with fMRI.
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48
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Prosperini L, Fanelli F, Petsas N, Sbardella E, Tona F, Raz E, Fortuna D, De Angelis F, Pozzilli C, Pantano P. Multiple Sclerosis: Changes in Microarchitecture of White Matter Tracts after Training with a Video Game Balance Board. Radiology 2014; 273:529-38. [DOI: 10.1148/radiol.14140168] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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49
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De Santis S, Drakesmith M, Bells S, Assaf Y, Jones DK. Why diffusion tensor MRI does well only some of the time: variance and covariance of white matter tissue microstructure attributes in the living human brain. Neuroimage 2013; 89:35-44. [PMID: 24342225 PMCID: PMC3988851 DOI: 10.1016/j.neuroimage.2013.12.003] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 12/01/2013] [Accepted: 12/03/2013] [Indexed: 01/07/2023] Open
Abstract
Fundamental to increasing our understanding of the role of white matter microstructure in normal/abnormal function in the living human is the development of MR-based metrics that provide increased specificity to distinct attributes of the white matter (e.g., local fibre architecture, axon morphology, and myelin content). In recent years, different approaches have been developed to enhance this specificity, and the Tractometry framework was introduced to combine the resulting multi-parametric data for a comprehensive assessment of white matter properties. The present work exploits that framework to characterise the statistical properties, specifically the variance and covariance, of these advanced microstructural indices across the major white matter pathways, with the aim of giving clear indications on the preferred metric(s) given the specific research question. A cohort of healthy subjects was scanned with a protocol that combined multi-component relaxometry with conventional and advanced diffusion MRI acquisitions to build the first comprehensive MRI atlas of white matter microstructure. The mean and standard deviation of the different metrics were analysed in order to understand how they vary across different brain regions/individuals and the correlation between them. Characterising the fibre architectural complexity (in terms of number of fibre populations in a voxel) provides clear insights into correlation/lack of correlation between the different metrics and explains why DT-MRI is a good model for white matter only some of the time. The study also identifies the metrics that account for the largest inter-subject variability and reports the minimal sample size required to detect differences in means, showing that, on the other hand, conventional DT-MRI indices might still be the safest choice in many contexts. We report an atlas of key white matter pathways in standard space. CHARMED provide more specific measures of axonal properties than DT-MRI metrics. Crossing fibres explain the correlation between myelin and diffusion indices. DT-MRI metrics need the smallest sample size to detect differences between groups.
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Affiliation(s)
- Silvia De Santis
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK.
| | - Mark Drakesmith
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK
| | - Sonya Bells
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK
| | - Yaniv Assaf
- Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978 Israel
| | - Derek K Jones
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK
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