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Somatosensory system

About: Somatosensory system is a research topic. Over the lifetime, 6371 publications have been published within this topic receiving 316900 citations.


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Journal ArticleDOI
01 Apr 2012-Pain
TL;DR: In this article, the authors determined patterns of sensory signs in complex regional pain syndrome (CRPS) type I and II and peripheral nerve injury (PNI) patients with upper-limb CRPS-I (n=298), CRPS II (n = 46), and PNI (n/72) were examined with quantitative sensory testing according to the protocol of the German Research Network on Neuropathic Pain.
Abstract: This study determined patterns of sensory signs in complex regional pain syndrome (CRPS) type I and II and peripheral nerve injury (PNI). Patients with upper-limb CRPS-I (n=298), CRPS-II (n=46), and PNI (n=72) were examined with quantitative sensory testing according to the protocol of the German Research Network on Neuropathic Pain. The majority of patients (66%-69%) exhibited a combination of sensory loss and gain. Patients with CRPS-I had more sensory gain (heat and pressure pain) and less sensory loss than patients with PNI (thermal and mechanical detection, hypoalgesia to heat or pinprick). CRPS-II patients shared features of CRPS-I and PNI. CRPS-I and CRPS-II had almost identical somatosensory profiles, with the exception of a stronger loss of mechanical detection in CRPS-II. In CRPS-I and -II, cold hyperalgesia/allodynia (28%-31%) and dynamic mechanical allodynia (24%-28%) were less frequent than heat or pressure hyperalgesia (36%-44%, 67%-73%), and mechanical hypoesthesia (31%-55%) was more frequent than thermal hypoesthesia (30%-44%). About 82% of PNI patients had at least one type of sensory gain. QST demonstrates more sensory loss in CRPS-I than hitherto considered, suggesting either minimal nerve injury or central inhibition. Sensory profiles suggest that CRPS-I and CRPS-II may represent one disease continuum. However, in contrast to recent suggestions, small fiber deficits were less frequent than large fiber deficits. Sensory gain is highly prevalent in PNI, indicating a better similarity of animal models to human patients than previously thought. These sensory profiles should help prioritize approaches for translation between animal and human research.

175 citations

Journal ArticleDOI
TL;DR: Different mechanisms are therefore responsible for the state-dependence of PSP amplitude and the spike frequency response to the whisker stimulus, and the state dependence of action potential generation in response to whisker stimulation may in part be related to a shift in threshold.
Abstract: Changes in spontaneous activity within the cortex recognized by subthreshold fluctuations of the membrane potential of cortical neurons modified the response of cortical neurons to sensory stimuli....

174 citations

Journal ArticleDOI
TL;DR: Data suggest that CPIA is a system which primarily regulates animals' responsiveness to external stimuli, in part by influencing segmentally organized behaviors.

174 citations

Journal ArticleDOI
TL;DR: The present study demonstrates that the primary somatosensory cortex of the rat contains a map of the entire body surface that is discernible with a routine anatomical staining technique, the succinic dehydrogenase reaction, indicating that the role of the periphery in organizing central neuronal structures during development previously demonstrated for the trigeminal system extends to the entire rat somatoensory system.
Abstract: The present study demonstrates that the primary somatosensory cortex of the rat contains a map of the entire body surface that is discernible with a routine anatomical staining technique, the succinic dehydrogenase reaction. The overall proportions of this map are relatively constant from rat to rat and very similar to those reported in previous physiological investigations (Welker: Brain Res. 26:259–275, '71, J. Comp. Neurol. 166:173–190, '76). We found 67% of the map to be related to the head of the rat, 15% to the forelimb, 14% to the trunk, and 4% to the hindlimb. Within the forelimb and indlimb representations, there is a consistent internal organization that can be related to specific peripheral structures (digits or palm pads). Further, damage to either the periphery or the nerves innervating these regions on the day of birth produces disruptions in the normal pattern, but damage on day 6 or later does not. We interpret these results as indicating that the role of the periphery in organizing central neuronal structures during development previously demonstrated for the trigeminal system extends to the entire rat somatosensory system. Comparison of the present results with physiological studies of adult cortical maps after peripheral damage suggests to us that different substrates underlie the changes reported in the adult.

174 citations

Journal ArticleDOI
TL;DR: It is demonstrated that prenatal nicotine exposure compromises neuronal maturation, leading to long-lasting alterations in the structure of key brain regions involved in cognition, learning, and memory.
Abstract: Offspring of women who smoke during pregnancy show behavioral abnormalities, including increased incidence of attentional deficit, learning disabilities, and cognitive dysfunction. Animal models indicate that nicotine elicits changes in neural cell replication and differentiation, leading to deficits in synaptic neurochemistry and behavioral performance, many of which first emerge at adolescence. We evaluated cellular morphology and regional architecture in the juvenile and adolescent hippocampus and the somatosensory cortex in rats exposed to nicotine prenatally. Pregnant rats were given nicotine throughout gestation via minipump infusion of 2 mg/kg/day, a regimen that elicits nicotine plasma levels comparable with those found in smokers. On postnatal days 21 and 30, brains were perfusion-fixed, coronal slices were taken between the anterior commissure and median eminence, and the morphology of the dorsal hippocampus and somatosensory cortex was characterized. In the hippocampal CA3 region and dentate gyrus, we found a substantial decrease in cell size, with corresponding decrements in cell layer thickness, and increments in cell packing density. Smaller, transient changes were seen in CA1. In layer 5 of the somatosensory cortex, although there was no significant decrement in the average cell size, there was a reduction in the proportion of medium-sized pyramidal neurons, and an increase in the proportion of smaller, nonpyramidal cells. All regions showed elevated numbers of glia. Taken together with previous work on neurochemical and functional defects, these data demonstrate that prenatal nicotine exposure compromises neuronal maturation, leading to long-lasting alterations in the structure of key brain regions involved in cognition, learning, and memory.

174 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023463
2022986
2021238
2020233
2019234