Short-term plasticity in primary somatosensory cortex of the rat after hindlimb suspension.

Since the last 25 years, the cortex is considered as a dynamic entity, susceptible of changes. Various types of modifications in stimuli may lead to the plasticity of the target neurons. These include immobilisation, denervation, amputation, deafferentation... In the somatosensory system, the most important changes are a substantial reorganisation of the cortical somatotopic representation, and an enlargement of the receptive fields (RF) of cortical neurons. Hindlimb suspension (HS) is characterized by the absence of weight-bearing and a reduced motor activity. In these conditions, the cutaneous receptors located on the foot sole are deactivated. Our hypothesis is that this condition of HS can produce a reorganisation of the somatosensory cortex (SmI) and a modification in the size of the cutaneous RF.