Read by QxMD icon Read


Jakub Limanowski, Felix Blankenburg
Spatially and temporally congruent visuotactile stimulation of a fake hand together with one's real hand may result in an illusory self-attribution of the fake hand. Although this illusion relies on a representation of the two touched body parts in external space, there is tentative evidence that, for the illusion to occur, the seen and felt touches also need to be congruent in an anatomical reference frame. We used functional magnetic resonance imaging and a somatotopical, virtual reality-based setup to isolate the neuronal basis of such a comparison...
2018: Frontiers in Human Neuroscience
Valéry Legrain, Louise Manfron, Marynn Garcia, Lieve Filbrich
How we perceive our body is shaped by sensory experiences with our surrounding environment, as witnessed by poor performance in tasks during which participants judge with their hands crossed the temporal order between two somatosensory stimuli, one applied on each hand. This suggests that somatosensory stimuli are not only processed according to a somatotopic representation but also a spatiotopic representation of the body. We investigated whether the perception of stimuli occurring in external space, such as visual stimuli, can also be influenced by the body posture and somatosensory stimuli...
January 1, 2018: Perception
Jenny L Davies, JaNean K Engelstad, Linde E Gove, Linda K Linbo, Rickey E Carter, Christopher Lynch, Nathan P Staff, Christopher J Klein, P James B Dyck, David N Herrmann, Peter J Dyck
INTRODUCTION: For sequential and somatotopic assessment of small fiber neuropathy (SFN), heat pain (HP) tests of hypoalgesia might be used instead of decreased counts of epidermal nerve fibers (ENFs), but then healthy subject reference values of HP thresholds are needed. METHODS: Using the CASE IVc system, HP thresholds of hypoalgesia were estimated for ten unilateral sites and counts of ENFs for four of them in healthy subjects. RESULTS: In healthy subjects, small but statistically significant differences of both HP thresholds of hypoalgesia and counts of ENFs were observed among tested sites...
March 15, 2018: Muscle & Nerve
Luis Garcia-Larrea, François Mauguière
Pain was considered to be integrated subcortically during most of the 20th century, and it was not until 1956 that focal injury to the parietal opercular-insular cortex was shown to produce selective loss of pain senses. The parietal operculum and adjacent posterior insula are the main recipients of spinothalamic afferents in primates. The innermost operculum appears functionally associated with the posterior insula and can be segregated histologically, somatotopically and neurochemically from the more lateral S2 areas...
2018: Handbook of Clinical Neurology
Manabu Zama, Yaeko Hara, Satoshi Fujita, Tadayoshi Kaneko, Masayuki Kobayashi
Nasal mucosa has roles in warming and humidifying inspired air and is highly sensitive to mechanical stimuli. Moreover, the upper part of the nasal mucosa expresses olfactory receptors processing olfactory information. Although the somatosensory map of the face in the primary (S1) and secondary (S2) somatosensory cortices is clearly documented, the map of the nasal mucosa and the effect of odors on their activities are largely unknown. This study aimed to identify the cortical regions in S1 and their temporal features in response to somatosensory stimulation of the nasal mucosa using an optical imaging technique in urethane-anesthetized rats...
March 5, 2018: Neuroscience
Christos Ganos, John Rothwell, Patrick Haggard
Inhibitory control is crucial for normal adaptive motor behavior. In hyperkinesias, such as tics, disinhibition within the cortico-striato-thalamo-cortical loops is thought to underlie the presence of involuntary movements. Paradoxically, tics are also subject to voluntary inhibitory control. This puzzling clinical observation questions the traditional definition of tics as purely involuntary motor behaviors. Importantly, it suggests novel insights into tic pathophysiology. In this review, we first define voluntary inhibitory tic control and compare it with other notions of tic control from the literature...
March 6, 2018: Movement Disorders: Official Journal of the Movement Disorder Society
Zuo Zhang, Yaoru Sun, Zijian Wang
Previous studies have shown that both reading action words and observing actions engage the motor cortex and Broca's area, but it is still controversial whether a somatotopic representation exists for action verbs within the motor cortex and whether Broca's area encodes action-specific semantics for verbs. Here we examined these two issues using a set of functional MRI experiments, including word reading, action observation and a movement localiser task. Results from multi-voxel pattern analysis (MVPA) showed a somatotopic organisation within the motor areas and action-specific activation in Broca's area for observed actions, suggesting the representation of action semantics for observed actions in these neural regions...
March 1, 2018: Brain and Language
Elson L So, Abdulrahman Alwaki
Electrical stimulation mapping (ESM) of the brain remains a major procedure for guiding epilepsy and tumor surgeries. This article collates available experiences and data in ESM to develop a guide for conducting the procedure. There are many factors that influence the yield of ESM. The stimulation parameters offered in this article need to be adjusted within safe limits to address the factors. Each ESM procedure should be tailored to the patient's age and baseline mental or psychological capacity. Stimulation-induced seizures and EEG afterdischarges disrupt ESM procedure and render the interpretation of the results difficult...
March 2018: Journal of Clinical Neurophysiology: Official Publication of the American Electroencephalographic Society
Scott Falci, Charlotte Indeck, Dave Barnkow
OBJECTIVE Surgically created lesions of the spinal cord dorsal root entry zone (DREZ) to relieve central pain after spinal cord injury (SCI) have historically been performed at and cephalad to, but not below, the level of SCI. This study was initiated to investigate the validity of 3 proposed concepts regarding the DREZ in SCI central pain: 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through sympathetic nervous system (SNS) pathways...
March 2, 2018: Journal of Neurosurgery. Spine
Christina M Cerkevich, Jon H Kaas
Cortical area 1 is a non-primary somatosensory area in the primate anterior parietal cortex that is critical to tactile discrimination. The corticocortical projections to area 1 in squirrel monkeys were determined by placing multiple injections of anatomical tracers into separate body part representations defined by multiunit microelectrode mapping in area 1. The pattern of labeled cells in the cortex indicated that area 1 has strong intrinsic connections within each body part representation, and has inputs from somatotopically matched regions of areas 3b, 3a, 2, and 5...
March 1, 2018: European Journal of Neuroscience
F H S Michelle Welman, Albertine E Smit, Joost L M Jongen, Dick Tibboel, Jos N van der Geest, Jan C Holstege
Many fMRI studies have shown activity in the cerebellum after peripheral nociceptive stimulation. We investigated whether the areas in the cerebellum that were activated after nociceptive thumb stimulation were separate from those after nociceptive toe stimulation. In an additional experiment, we investigated the same for the anticipation of a nociceptive stimulation on the thumb or toe. For his purpose, we used fMRI after an electrical stimulation of the thumb and toe in 19 adult healthy volunteers. Following nociceptive stimulation, different areas were activated by stimulation on the thumb (lobule VI ipsilaterally and Crus II mainly contralaterally) and toe (lobules VIII-IX and IV-V bilaterally and lobule VI contralaterally), i...
February 26, 2018: Cerebellum
Ronan V da Silva, Helge C Johannssen, Matthias T Wyss, R Brian Roome, Farin B Bourojeni, Nicolas Stifani, Ashley P L Marsh, Monique M Ryan, Paul J Lockhart, Richard J Leventer, Linda J Richards, Bernard Rosenblatt, Myriam Srour, Bruno Weber, Hanns Ulrich Zeilhofer, Artur Kania
Avoidance of environmental dangers depends on nociceptive topognosis, or the ability to localize painful stimuli. This is proposed to rely on somatotopic maps arising from topographically organized point-to-point connections between the body surface and the CNS. To determine the role of topographic organization of spinal ascending projections in nociceptive topognosis, we generated a conditional knockout mouse lacking expression of the netrin1 receptor DCC in the spinal cord. These mice have an increased number of ipsilateral spinothalamic connections and exhibit aberrant activation of the somatosensory cortex in response to unilateral stimulation...
January 30, 2018: Cell Reports
William Gaetz, Sudha K Kessler, Tim P L Roberts, Jeffrey I Berman, Todd J Levy, Michelle Hsia, Deborah Humpl, Erin S Schwartz, Sandra Amaral, Ben Chang, Lawrence Scott Levin
In this repeated measures case study, we show that sensory deafferentation after limb amputation leads to changes in cortical somatotopic maps which are reversible after restoration of sensory input. Using magnetoencephalography (MEG), we observed in a child with bilateral hand transplants large-scale shifts in somatosensory lip cortical representation from anatomic hand area to anatomic face region. After recovery of tactile sensation in the digits, responses to finger stimulation were localized to orthotopic sensory cortex, but with atypical electrophysiologic features (amplitude and frequencies)...
January 2018: Annals of Clinical and Translational Neurology
Konstantina Kalogianni, Andreas Daffertshofer, Frans C T van der Helm, Alfred C Schouten, Jan C de Munck
In searching for clinical biomarkers of the somatosensory function, we studied reproducibility of somatosensory potentials (SEP) evoked by finger stimulation in healthy subjects. SEPs induced by electrical stimulation and especially after median nerve stimulation is a method widely used in the literature. It is unclear, however, if the EEG recordings after finger stimulation are reproducible within the same subject. We tested in five healthy subjects the consistency and reproducibility of responses through bootstrapping as well as test-retest recordings...
January 20, 2018: Brain Topography
Pai-Feng Yang, Ruiqi Wu, Tung-Lin Wu, Zhaoyue Shi, Li Min Chen
This study addresses one long-standing question of whether functional separations are preserved for somatosensory modalities of touch, heat and cold nociception within primate primary somatosensory (S1) cortex. This information is critical for understanding how the nature of pain is represented in the primate brain. Using a combination of submillimeter-resolution fMRI and microelectrode local field potential (LFP) and spike recordings, we identified spatially-segregated cortical zones for processing touch, nociceptive heat and cold stimuli in somatotopically appropriate areas 3a, 3b, 1, and 2 of S1 in male monkeys...
January 15, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Yael Oran, Izhar Bar-Gad
Fast-spiking interneurons (FSIs) exert powerful inhibitory control over the striatum and are hypothesized to balance the massive excitatory cortical and thalamic input to this structure. We recorded neuronal activity in the dorsolateral striatum and globus pallidus (GP) concurrently with the detailed movement kinematics of freely behaving female rats before and after selective inhibition of FSI activity using IEM-1460 microinjections. The inhibition led to the appearance of episodic rest tremor in the body part that depended on the somatotopic location of the injection within the striatum...
February 14, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Daniele Impieri, Michela Gamberini, Lauretta Passarelli, Marcello G P Rosa, Claudio Galletti
The exposed surface of the superior parietal lobule in macaque brain contains two architectonically defined areas named PEc and PE. The aim of the present study is the characterization of thalamic afferents of these two areas. For this purpose, retrograde neuronal tracers were injected, or placed in crystal form, in areas PEc and PE. We found that the two areas show a similar pattern of thalamic inputs, mainly originating from Lateral Posterior (LP), Pulvinar (Pul), Ventral Posterior Lateral (VPL), and Ventral Lateral (VL) nuclei, all structures known to be involved in visual, somatosensory, and/or sensorimotor processing...
January 10, 2018: Journal of Comparative Neurology
Christos Ganos, Elisa R Ferrè, Angela Marotta, Panagiotis Kassavetis, John Rothwell, Kailash P Bhatia, Patrick Haggard
OBJECTIVE: To assess the specificity of cortical inhibitory deficits in cervical dystonia patients. METHODS: A systematic test battery was developed to assess spatial and temporal aspects of cortical inhibition, in motor and somatosensory systems of the hand. We tested 17 cervical dystonia (CD) patients and 19 controls assessing somatosensory spatial inhibition (grating orientation test, interdigital feedforward subliminal inhibition), somatosensory temporal inhibition (temporal discrimination threshold, feedforward subliminal inhibition), motor spatial inhibition (surround inhibition), and motor temporal inhibition (short interval intracortical inhibition)...
December 1, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Esther Kuehn, Patrick Haggard, Arno Villringer, Burkhard Pleger, Martin I Sereno
Sensory perception relies on the precise neuronal encoding of modality-specific environmental features in primary sensory cortices. Some studies have reported the penetration of signals from other modalities even into early sensory areas. So far, no comprehensive account of maps induced by "foreign sources" exists. We addressed this question using surface-based topographic mapping techniques applied to ultra-high resolution fMRI neuroimaging data, measured in female participants. We show that fine-grained finger maps in human primary somatosensory cortex, area 3b, are somatotopically activated not only during tactile mechanical stimulation, but also when viewing the same fingers being touched...
January 4, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Franck-Emmanuel Roux, Imène Djidjeli, Jean-Baptiste Durand
KEY POINTS: We performed a prospective electrostimulation study, based on 50 operated intact patients, to acquire accurate MNI coordinates of the functional areas of the somatosensory homunculus. In the contralateral BA1, the hand representation displayed not only medial-to-lateral, little-finger-to-thumb, but also rostral-to-caudal discrete somatotopy, with the tip of each finger located more caudally than the proximal phalanx. The analysis of the MNI body coordinates showed rare inter-individual variations in the medial-to-lateral somatotopic organization in these patients with rather different intensity thresholds needed to elicit sensations in different body parts...
March 1, 2018: Journal of Physiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"