[Functional reorganization of rat somatosensory cortex induced by synchronous afferent stimulation]

Detailed microelectrode maps of the S1 vibrissal zone were derived in a series of normal adult rats in which the tips of a pair of adjacent vibrissae had been glued together for 4-8 days to promote their simultaneous stimulation. The results showed that there was a significant (on average, 5- to 6-fold) enlargement of the conjoint functional cortical representation of temporarily fused whiskers. when compared with matched normative data. The histological reconstruction of barrel fields in experimental cases revealed that these enlarged cortical representations of fused whiskers occupied cortical zones equivalent to the areas of several barrels. The present experiments support the hypothesis that cortical representation and receptive fields are shaped by the relative magnitudes and time structures of afferent inputs.