Sensory and Motor Functions of Face Primary Somatosensory Cortex in The Primate
Mark J Rowe, Yoshiaki Iwamura in Somatosensory Processing: From Single Neuron to Brain Imaging, 2001
The primary somatosensory cortex (SI), comprising cytoarchitectonie areas 3a, 3b, 1 and 2 of the cerebral cortex, plays a critical role in primates in the processing of somatosensory information generated by passive stimulation of peripheral tissues or elicited by active movements. The thermode provided an experimental means by which the effects of reversible cold block-induced inactivation of SI could be tested on orofacial motor behaviour and on motor cortex neuronal activity in the awake monkey. During bilateral cooling of face SI in two monkeys tested, there was a statistically significant reduction in the success rates for the performance of the tongue protrusion task in comparison with the control series of trials. Other properties of the face SI neurones indicated the involvement of face SI also in motor control. The original neuronal data indicate an important role for face SI in operantly conditioned orofacial movements.
Tactile acuity and predominance of central sensitization in subjects with non-specific persistent low back pain
Published in Somatosensory & Motor Research, 2019
Cristhian Saavedra Santiesteban, José Cárdenas S., Karen Low H., R. Mauricio Barría
Aim: This study aimed to evaluate differences in tactile acuity (TA) in people with non-specific persistent low back pain (NSPLBP) with and without predominant central sensitisation (CS). Method: An analytical cross-sectional study was conducted with 45 participants divided into three groups: (i) subjects with NSPLBP with predominant CS (n = 14), (ii) subjects with NSPLBP without predominant CS (n = 16) and (iii) subjects without low back pain (n = 15). Using an analogue calliper, TA was measured using the two-point discrimination threshold (TPD) in the three groups, both horizontally and vertically in the painful region. The analysis was based on the comparison of median discrimination thresholds between groups using the Kruskal-Wallis test. Result: A higher median TPD value was observed in the group with NSPLBP with predominant CS (vertical measurement 37.5 mm; horizontal measurement 52.5 mm) compared to the group with NSPLBP without predominant CS (vertical measurement 32.5 mm; horizontal measurement 33.8 mm) and the group without low back pain (vertical measurement 30 mm; horizontal measurement 27.5 mm) (p
Spatiotemporal patterns of neural activity in response to electroacupuncture stimulation in the rodent primary somatosensory cortex
Published in Neurological Research, 2010
Younbyoung Chae, Hi-Joon Park, Dae-Hyun Hahm, Bae-Hwan Lee, Hun-Kuk Park, Hyejung Lee
Objectives: Optical imaging technique enables the recording of cortical activities in multiple sites of the primary somatosensory cortex in real time. The present study was aimed to visualize neural activity in response to the acupuncture stimulation in the rodent primary somatosensory cortex by a high-resolution optical imaging system using voltage-sensitive dyes. Methods: Optical imaging was exploited to examine the temporal–spatial characteristic of rat primary somatosensory cortex during electroacupuncture stimulation (6 mA intensity and 2 ms duration) at two pairs of acupuncture points (ST36-SP6 or GB34-BL57). Results: In terms of magnitude and duration of the optical response, there was no difference between ST36-SP6 and GB34-BL57 stimulations. Maximally activated sites by electroacupuncture stimulation to the different acupuncture points were spatially differentiated in rat primary somatosensory cortex. Discussion: The results indicate that neuronal responses to electroacupuncture stimulation can be visualized in rat primary somatosensory cortex using an optical imaging system. The topographical mapping of acupuncture points in primary somatosensory cortex will make a significant contribution to the understanding of neural mechanisms of the acupuncture treatment and Meridian phenomena.
Somatosensory Cortical Activation in Cervical Dystonia and Its Modulation With Botulinum Toxin: An fMRI Study
Published in International Journal of Neuroscience, 2012
Robert Opavský, Petr Hluštík, Pavel Otruba, Petr Kaňovský
Converging data on focal dystonias suggest a widespread disorder of somatosensory processing. The aims of our study were, first, to assess somatosensory activation patterns in cervical dystonia (CD) beyond the representation of the affected body parts and, second, to search for task-related activation changes induced by botulinum toxin type-A (BoNT-A) therapy. Functional magnetic resonance imaging (MRI) during electrical median nerve stimulation was employed in seven CD patients and nine controls; the examination was repeated 4 weeks after BoNT-A application to dystonic neck muscles. The pretreatment activation map of patients showed activation in the contralateral primary somatosensory cortex, but missing activation in the secondary somatosensory cortex and insula, in contrast to controls and patients after treatment. Clinically significant effect of BoNT-A therapy was associated with a significant increase of BOLD response in the contralateral secondary somatosensory, insular, and inferior parietal cortices. The posttreatment somatosensory maps of patients did not significantly differ from controls. This study has brought evidence of widespread disruption of somatosensory processing in CD and its modification with BoNT-A therapy.
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