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Somatosensory cortex

Mark N Wallace, Matthew J Cronin, Richard W Bowtell, Ian S Scott, Alan R Palmer, Penny A Gowland
Functional magnetic resonance imaging (fMRI) studies of the auditory region of the temporal lobe would benefit from the availability of image contrast that allowed direct identification of the primary auditory cortex, as this region cannot be accurately located using gyral landmarks alone. Previous work has suggested that the primary area can be identified in magnetic resonance (MR) images because of its relatively high myelin content. However, MR images are also affected by the iron content of the tissue and in this study we sought to confirm that different MR image contrasts did correlate with the myelin content in the gray matter and were not primarily affected by iron content as is the case in the primary visual and somatosensory areas...
2016: Frontiers in Neuroscience
Javier Gonzalez-Castillo, Gang Chen, Thomas E Nichols, Peter A Bandettini
Here we report an exploratory within-subject variance decomposition analysis conducted on a task-based fMRI dataset with an unusually large number of repeated measures (i.e., 500 trials in each of three different subjects) distributed across 100 functional scans and 9 to 10 different sessions. Within-subject variance was segregated into four primary components: variance across-sessions, variance across-runs within a session, variance across-blocks within a run, and residual measurement/modeling error. Our results reveal inhomogeneous and distinct spatial distributions of these variance components across significantly active voxels in grey matter...
October 20, 2016: NeuroImage
Catherine S Hubbard, Lino Becerra, Jonathan H Smith, Justin M DeLange, Ryan M Smith, David F Black, Kirk M Welker, Rami Burstein, Fred M Cutrer, David Borsook
The aim of this study was to identify structural and functional brain changes that accompanied the transition from chronic (CM; ≥15 headache days/month) to episodic (EM; <15 headache days/month) migraine following prophylactic treatment with onabotulinumtoxinA (BoNT-A). Specifically, we examined whether CM patients responsive to prophylaxis (responders; n = 11), as evidenced by a reversal in disease status (defined by at least a 50% reduction in migraine frequency and <15 headache days/month), compared to CM patients whose migraine frequency remained unchanged (non-responders; n = 12), showed differences in cortical thickness using surface-based morphometry...
2016: Frontiers in Human Neuroscience
Davide Zanchi, Anne Christin Meyer-Gerspach, Claudia Suenderhauf, Katharina Janach, Carel W le Roux, Sven Haller, Jürgen Drewe, Christoph Beglinger, Bettina K Wölnerhanssen, Stefan Borgwardt
Depending on their protein content, single meals can rapidly influence the uptake of amino acids into the brain and thereby modify brain functions. The current study investigates the effects of two different amino acids on the human gut-brain system, using a multimodal approach, integrating physiological and neuroimaging data. In a randomized, placebo-controlled trial, L-tryptophan, L-leucine, glucose and water were administered directly into the gut of 20 healthy subjects. Functional MRI (fMRI) in a resting state paradigm (RS), combined with the assessment of insulin and glucose blood concentration, was performed before and after treatment...
October 20, 2016: Scientific Reports
Siyu Zhang, Min Xu, Wei-Cheng Chang, Chenyan Ma, Johnny Phong Hoang Do, Daniel Jeong, Tiffany Lei, Jiang Lan Fan, Yang Dan
Long-range projections from the frontal cortex are known to modulate sensory processing in multiple modalities. Although the mouse has become an increasingly important animal model for studying the circuit basis of behavior, the functional organization of its frontal cortical long-range connectivity remains poorly characterized. Here we used virus-assisted circuit mapping to identify the brain networks for top-down modulation of visual, somatosensory and auditory processing. The visual cortex is reciprocally connected to the anterior cingulate area, whereas the somatosensory and auditory cortices are connected to the primary and secondary motor cortices...
October 17, 2016: Nature Neuroscience
Jianing Yu, Diego A Gutnisky, S Andrew Hires, Karel Svoboda
We rely on movement to explore the environment, for example, by palpating an object. In somatosensory cortex, activity related to movement of digits or whiskers is suppressed, which could facilitate detection of touch. Movement-related suppression is generally assumed to involve corollary discharges. Here we uncovered a thalamocortical mechanism in which cortical fast-spiking interneurons, driven by sensory input, suppress movement-related activity in layer 4 (L4) excitatory neurons. In mice locating objects with their whiskers, neurons in the ventral posteromedial nucleus (VPM) fired in response to touch and whisker movement...
October 17, 2016: Nature Neuroscience
Simon P Fisher, Nanyi Cui, Laura E McKillop, Jessica Gemignani, David M Bannerman, Peter L Oliver, Stuart N Peirson, Vladyslav V Vyazovskiy
Prolonged wakefulness is thought to gradually increase 'sleep need' and influence subsequent sleep duration and intensity, but the role of specific waking behaviours remains unclear. Here we report the effect of voluntary wheel running during wakefulness on neuronal activity in the motor and somatosensory cortex in mice. We find that stereotypic wheel running is associated with a substantial reduction in firing rates among a large subpopulation of cortical neurons, especially at high speeds. Wheel running also has longer-term effects on spiking activity across periods of wakefulness...
October 17, 2016: Nature Communications
Asanori Kiyuna, Norimoto Kise, Munehisa Hiratsuka, Shunsuke Kondo, Takayuki Uehara, Hiroyuki Maeda, Akira Ganaha, Mikio Suzuki
OBJECTIVES: Spasmodic dysphonia (SD) is considered a focal dystonia. However, the detailed pathophysiology of SD remains unclear, despite the detection of abnormal activity in several brain regions. The aim of this study was to clarify the pathophysiological background of SD. STUDY DESIGN: This is a case-control study. METHODS: Both task-related brain activity measured by functional magnetic resonance imaging by reading the five-digit numbers and resting-state functional connectivity (FC) measured by 150 T2-weighted echo planar images acquired without any task were investigated in 12 patients with adductor SD and in 16 healthy controls...
October 13, 2016: Journal of Voice: Official Journal of the Voice Foundation
Katarzyna Lebida, Jerzy W Mozrzymas
Experience and learning in adult primary somatosensory cortex are known to affect neuronal circuits by modifying both excitatory and inhibitory transmission. Synaptic plasticity phenomena provide a key substrate for cognitive processes, but precise description of the cellular and molecular correlates of learning is hampered by multiplicity of these mechanisms in various projections and in different types of neurons. Herein, we investigated the impact of associative learning on neuronal plasticity in distinct types of postsynaptic neurons by checking the impact of classical conditioning (pairing whisker stroking with tail shock) on the spike timing-dependent plasticity (t-LTP and t-LTD) in the layer IV to II/III vertical pathway of the mouse barrel cortex...
October 15, 2016: Molecular Neurobiology
Andrea Becerra-Calixto, Gloria Patricia Cardona-Gómez
Cerebral ischemia is a cerebrovascular episode that generates a high incidence of death and physical and mental disabilities worldwide. Excitotoxicity, release of free radicals, and exacerbated immune response cause serious complications in motor and cognitive areas during both short and long time frames post-ischemia. CDK5 is a kinase that is widely involved in the functions of neurons and astrocytes, and its over-activation is implicated in neurodegenerative processes. In this study, we evaluated the brain parenchymal response to the transplantation of CDK5-knockdown astrocytes into the somatosensory cortex after ischemia in rats...
October 15, 2016: Molecular Neurobiology
Laura M J Fernandez, Jean-Christophe Comte, Pierre Le Merre, Jian-Sheng Lin, Paul-A Salin, Sylvain Crochet
Although low-frequency (LF < 10 Hz) activities have been considered as a hallmark of nonrapid eye movement (NREM) sleep, several studies have recently reported LF activities in the membrane potential of cortical neurons from different areas in awake mice. However, little is known about the spatiotemporal organization of LF activities across cortical areas during wakefulness and to what extent it differs during NREM sleep. We have thus investigated the dynamics of LF activities across cortical areas in awake and sleeping mice using chronic simultaneous local field potential recordings...
October 14, 2016: Cerebral Cortex
Gerard Derosiere, Alexandre Zénon, Andrea Alamia, Julie Duque
In the present study, we investigated the functional contribution of the human primary motor cortex (M1) to motor decisions. Continuous theta burst stimulation (cTBS) was used to alter M1 activity while participants performed a decision-making task in which the reward associated with the subjects' responses (right hand finger movements) depended on explicit and implicit value-based rules. Subjects performed the task over two consecutive days and cTBS occurred in the middle of Day 2, once the subjects were just about to implement implicit rules, in addition to the explicit instructions, to choose their responses, as evident in the control group (cTBS over the right somatosensory cortex)...
October 11, 2016: NeuroImage
Maria Dadarlat, Philip Sabes
Naturalistic control of brain-machine interfaces will require artificial proprioception, potentially delivered via intracortical microstimulation (ICMS).We have previously shown that multi-channel ICMS can guide a monkey reaching to unseen targets in a planar workspace. Here, we expand on that work, asking how ICMS is decoded into target angle and distance by analyzing the performance of a monkey when ICMS feedback was degraded. From the resulting pattern of errors, we found that the animal's estimate of target direction was consistent with a weighted circular-mean strategy-close to the optimal decoding strategy given the ICMS encoding...
October 11, 2016: IEEE Transactions on Haptics
Bethel C A Osuagwu, Leslie Wallace, Mathew Fraser, Aleksandra Vuckovic
OBJECTIVE: To compare neurological and functional outcomes between two groups of hospitalised patients with subacute tetraplegia. APPROACH: Seven patients received 20 sessions of brain computer interface (BCI) controlled functional electrical stimulation (FES) while five patients received the same number of sessions of passive FES for both hands. The neurological assessment measures were event related desynchronization (ERD) during movement attempt, Somatosensory evoked potential (SSEP) of the ulnar and median nerve; assessment of hand function involved the range of motion (ROM) of wrist and manual muscle test...
October 14, 2016: Journal of Neural Engineering
Merve Cikili Uytun, Emel Karakaya, Didem Behice Oztop, Serife Gengec, Kazım Gumus, Sevgi Ozmen, Selim Doğanay, Semra Icer, Esra Demirci, Saliha Demirel Ozsoy
It is known that patients with Attention Deficit and Hyperactivity disorder (ADHD) and Conduct disorder (CD) commonly shows greater symptom severity than those with ADHD alone and worse outcomes. This study researches whether Default mode network (DMN) is altered in adolescents with ADHD + CD, relative to ADHD alone and controls or not. Ten medication-naïve boys with ADHD + CD, ten medication-naïve boys with ADHD and 10-age-matched typically developing (TD) controls underwent functional magnetic resonance imaging (fMRI) scans in the resting state and neuropsychological tasks such as the Wisconsin Card Sorting Test (WCST), Stroop Test TBAG Form (STP), Auditory Verbal learning Test (AVLT), Visual Auditory Digit Span B (VADS B) were applied to all the subjects included...
October 13, 2016: Brain Imaging and Behavior
Sharlene N Flesher, Jennifer L Collinger, Stephen T Foldes, Jeffrey M Weiss, John E Downey, Elizabeth C Tyler-Kabara, Sliman J Bensmaia, Andrew B Schwartz, Michael L Boninger, Robert A Gaunt
Intracortical microstimulation of the somatosensory cortex offers the potential for creating a sensory neuroprosthesis to restore tactile sensation. Whereas animal studies have suggested that both cutaneous and proprioceptive percepts can be evoked using this approach, the perceptual quality of the stimuli cannot be measured in these experiments. We show that microstimulation within the hand area of the somatosensory cortex of a person with long-term spinal cord injury evokes tactile sensations perceived as originating from locations on the hand and that cortical stimulation sites are organized according to expected somatotopic principles...
October 13, 2016: Science Translational Medicine
Madelon M E Riem, Marinus H van IJzendoorn, Pietro De Carli, Ad J J M Vingerhoets, Marian J Bakermans-Kranenburg
The current fMRI study examines brain activity during the perception of infant and adult tears. Infant tears evoke stronger responses in the visual cortex than adult tears, indicating that infant tears are highly salient. In addition, our study shows that infant tears uniquely activate somatosensory pain regions, which could stimulate actions directed at the elimination of the source of pain. Shedding tears may be a strong means to elicit the parent's sharing of the infant's feelings,, thereby strengthening caregiver-infant bonding and securing infant survival...
October 11, 2016: Social Neuroscience
Marina V Sysoeva, Lyudmila V Vinogradova, Galina D Kuznetsova, Ilya V Sysoev, Clementina M van Rijn
PURPOSE: Spike-and-wave discharges (SWDs) recorded in the cortical EEGs of WAG/Rij rats are the hallmark for absence epilepsy in this model. Although this type of epilepsy was long regarded as a form of primary generalized epilepsy, it is now recognized that there is an initiation zone - the perioral region of the somatosensory cortex. However, networks involved in spreading the seizure are not yet fully known. Previously, the dynamics of coupling between different layers of the perioral cortical region and between these zones and different thalamic nuclei was studied in time windows around the SWDs, using nonlinear Granger causality...
October 8, 2016: Epilepsy & Behavior: E&B
Ivan Vorisek, Michael Syka, Lydia Vargova
Diffusion-weighted magnetic resonance (DW-MR) is an important diagnostic tool in Huntington disease (HD), a fatal hereditary neurodegenerative disorder. To clarify the nature of diffusivity changes in HD, we compared the apparent diffusion coefficient of water (ADCW ) acquired by DW-MR with extracellular space volume fraction α and tortuosity λ, measured by the iontophoretic method in the R6/2 mouse model of HD and in wild-type controls (WT). In anisotropic globus pallidus (GP), diffusion measurements were performed in the mediolateral (x), rostrocaudal (y), and ventrodorsal (z) axes...
October 11, 2016: Journal of Neuroscience Research
Hannah Hamburg, Svenja V Trossbach, Verian Bader, Caroline Chwiesko, Anja Kipar, Magdalena Sauvage, William R Crum, Anthony C Vernon, Hans J Bidmon, Carsten Korth
To date, unequivocal neuroanatomical features have been demonstrated neither for sporadic nor for familial schizophrenia. Here, we investigated the neuroanatomical changes in a transgenic rat model for a subset of sporadic chronic mental illness (CMI), which modestly overexpresses human full-length, non-mutant Disrupted-in-Schizophrenia 1 (DISC1), and for which aberrant dopamine homeostasis consistent with some schizophrenia phenotypes has previously been reported. Neuroanatomical analysis revealed a reduced density of dopaminergic neurons in the substantia nigra and reduced dopaminergic fibres in the striatum...
October 10, 2016: Scientific Reports
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