scholarly journals Functional Subdivisions of Magnocellular Cell Groups in Human Basal Forebrain: Test–Retest Resting-State Study at Ultra-high Field, and Meta-analysis

2018 ◽  
Vol 29 (7) ◽  
pp. 2844-2858 ◽  
Author(s):  
Rui Yuan ◽  
Bharat B Biswal ◽  
Laszlo Zaborszky
Keyword(s):  
Functional Connectivity ◽  
Spatial Resolution ◽  
Basal Forebrain ◽  
High Field ◽  
Meta Analysis ◽  
Functional Integration ◽  
Cortical Projection ◽  
Ultra High Field ◽  
Functional Connection ◽  
Projection System

Abstract The heterogeneous neuronal subgroups of the basal forebrain corticopetal system (BFcs) have been shown to modulate cortical functions through their cholinergic, gamma-aminobutyric acid-ergic, and glutamatergic projections to the entire cortex. Although previous studies suggested that the basalo-cortical projection system influences various cognitive functions, particularly via its cholinergic component, these studies only focused on certain parts of the BFcs or nearby structures, leaving aside a more systematic picture of the functional connectivity of BFcs subcompartments. Moreover, these studies lacked the high-spatial resolution and the probability maps needed to identify specific subcompartments. Recent advances in the ultra-high field 7T functional magnetic resonance imaging (fMRI) provided potentially unprecedented spatial resolution of functional MRI images to study the subdivision of the BFcs. In this study, the BF space containing corticopetal cells was divided into 3 functionally distinct subdivisions based on functional connection to cortical regions derived from fMRI. The overall functional connection of each BFcs subdivision was examined with a test-retest study. Finally, a meta-analysis was used to study the related functional topics of each BF subdivision. Our results demonstrate distinct functional connectivity patterns of these subdivisions along the rostrocaudal axis of the BF. All three compartments have shown consistent segregation and overlap at specific target regions including the hippocampus, insula, thalamus, and the cingulate gyrus, suggesting functional integration and separation in BFcs.

scholarly journals Whole brain mapping of somatosensory responses in awake marmosets investigated with ultra-high-field fMRI

2020 ◽  
Vol 124 (6) ◽  
pp. 1900-1913
Author(s):  
Justine C. Cléry ◽  
Yuki Hori ◽  
David J. Schaeffer ◽  
Joseph S. Gati ◽  
J. Andrew Pruszynski ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Brain Mapping ◽  
Resting State ◽  
High Field ◽  
Body Representation ◽  
Resting State Fmri ◽  
Fmri Data ◽  
Ultra High Field ◽  
Somatosensory Stimulation ◽  
Somatosensory Responses

We used somatosensory stimulation combined with functional MRI (fMRI) in awake marmosets to reveal the topographic body representation in areas S1, S2, thalamus, and putamen. We showed the existence of a body representation organization within the thalamus and the cingulate cortex by computing functional connectivity maps from seeds defined in S1/S2 using resting-state fMRI data. This noninvasive approach will be essential for chronic studies by guiding invasive recording and manipulation techniques.

scholarly journals Ultra-high field (7T) functional magnetic resonance imaging in amyotrophic lateral sclerosis

2020 ◽  
Author(s):  
Robert L. Barry ◽  
Suma Babu ◽  
Sheeba Arnold Anteraper ◽  
Christina Triantafyllou ◽  
Boris Keil ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Amyotrophic Lateral Sclerosis ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Functional Connectivity ◽  
High Field ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Ultra High Field ◽  
Lateral Sclerosis

AbstractAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the central nervous system that results in a progressive loss of motor function and ultimately death. It is crit-ical, yet also challenging, to develop non-invasive biomarkers to identify, localize, measure and/or track biological mechanisms implicated in ALS. Such biomarkers may also provide clues to identify potential molecular targets for future therapeutic trials. Herein we report on twelve participants with ALS and nine age-matched healthy controls who underwent high-resolution resting state functional magnetic resonance imaging at an ultra-high field of 7 Tesla. Group-level whole-brain analyses revealed a disruption in long-range functional connectivity between the superior sensorimotor cortex (in the precentral gyrus) and bi-lateral cerebellar lobule VI. Post hoc analyses using atlas-derived left and right cerebellar lobule VI revealed decreased functional connectivity in ALS participants that predomi-nantly map to bilateral postcentral and precentral gyri. Cerebellar lobule VI is a transition zone between anterior motor networks and posterior non-motor networks in the cerebellum, and has been associated with a wide range of key functions including complex motor and cognitive processing tasks. Our observation of the involvement of cerebellar lobule VI adds to the growing number of studies implicating the cerebellum in ALS. Future avenues of scientific investigation should consider how high-resolution imaging at 7T may be leveraged to visualize differences in functional connectivity disturbances in various genotypes and phenotypes of ALS along the ALS-frontotemporal dementia spectrum.

scholarly journals Ultra-high-field 7-T MRI in multiple sclerosis and other demyelinating diseases: from pathology to clinical practice

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Nicolo’ Bruschi ◽  
Giacomo Boffa ◽  
Matilde Inglese
Keyword(s):  
Multiple Sclerosis ◽  
High Field ◽  
Neurological Diseases ◽  
Lesion Detection ◽  
Demyelinating Diseases ◽  
Metabolic Imaging ◽  
Central Vein ◽  
Ultra High Field ◽  
Functional Features

Abstract Magnetic resonance imaging (MRI) is essential for the early diagnosis of multiple sclerosis (MS), for investigating the disease pathophysiology, and for discriminating MS from other neurological diseases. Ultra-high-field strength (7-T) MRI provides a new tool for studying MS and other demyelinating diseases both in research and in clinical settings. We present an overview of 7-T MRI application in MS focusing on increased sensitivity and specificity for lesion detection and characterisation in the brain and spinal cord, central vein sign identification, and leptomeningeal enhancement detection. We also discuss the role of 7-T MRI in improving our understanding of MS pathophysiology with the aid of metabolic imaging. In addition, we present 7-T MRI applications in other demyelinating diseases. 7-T MRI allows better detection of the anatomical, pathological, and functional features of MS, thus improving our understanding of MS pathology in vivo. 7-T MRI also represents a potential tool for earlier and more accurate diagnosis.

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