Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-10-2
pubmed:abstractText
Hypodynamia-hypokinesia (HH) is a model of hindpaw sensory deprivation. It is obtained by unloading of the hindquarters during 14 days. In this situation, the feet are not in contact with the ground and as a consequence, the cutaneous receptors are not activated; the sensory input to the primary somatosensory cortex (SmI) is thus reduced. In a previous study, we have shown that HH induced a cortical reorganisation of the hindlimb representation. The understanding of the mechanisms involved in cortical map plasticity requires a close examination of the changes in response properties of cortical neurons during HH. The aim of the present study was thus to study the characteristics of neurons recorded from granular and infragranular layers in hindlimb representation of SmI. A total of 289 cortical neurons were recorded (158 from control rats and 131 from HH rats) in pentobarbital-anaesthetized rats. Cutaneous threshold, cutaneous receptive fields, spontaneous activity (discharge rate and instantaneous frequency) and activity evoked by air-jet stimulation (response latency and duration, amplitude) were analysed. The present study suggests that activity-dependent changes occur in the cortex. The duration of the spike waveform presented two populations of spikes: thin-spike cells (<1 ms, supposed to be inhibitory interneurons) and regular cells (>1 ms). Thin-spike cells were less frequently encountered in HH than in control rats. The analysis of regular cells revealed that after HH (1) spontaneous activity was unchanged and (2) cortical somatosensory neurons were more responsive: the cutaneous threshold was reduced and the response magnitude increased. Taken together, these results suggest a down-regulation of GABAergic function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
121
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
433-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:14522001-Action Potentials, pubmed-meshheading:14522001-Animals, pubmed-meshheading:14522001-Electric Stimulation, pubmed-meshheading:14522001-Electrophysiology, pubmed-meshheading:14522001-Evoked Potentials, Somatosensory, pubmed-meshheading:14522001-Hindlimb, pubmed-meshheading:14522001-Hypokinesia, pubmed-meshheading:14522001-Male, pubmed-meshheading:14522001-Mechanoreceptors, pubmed-meshheading:14522001-Neural Pathways, pubmed-meshheading:14522001-Neurons, pubmed-meshheading:14522001-Rats, pubmed-meshheading:14522001-Rats, Wistar, pubmed-meshheading:14522001-Reaction Time, pubmed-meshheading:14522001-Sensory Deprivation, pubmed-meshheading:14522001-Sensory Thresholds, pubmed-meshheading:14522001-Skin, pubmed-meshheading:14522001-Somatosensory Cortex, pubmed-meshheading:14522001-Time
pubmed:year
2003
pubmed:articleTitle
A 14-day period of hindpaw sensory deprivation enhances the responsiveness of rat cortical neurons.
pubmed:affiliation
Laboratoire de Plasticité Neuromusculaire, EA 1032, IFR 118, Université des Sciences et Technologies de Lille, Bâtiment SN4, F-59655, Villeneuve d'Ascq Cedex, France.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't