Suppression of temporary deafferentation-induced plasticity in the primary somatosensory cortex of rats by GABA antagonist.

Single neurons were simultaneously recorded in the primary somatosensory (SI) cortex of rats to characterize the effects of applied bicuculline on the temporary deafferentation (TD)-induced plasticity. In the absence of TD, bicuculline application caused TD-like plasticity such as the expansion of receptive field (RF) and facilitation of sensory transmission in RF boundary cell. It also induced the originally unresponsive neurons to be responsive to the peripheral stimulation. In RF center neurons, TD-induced suppression of sensory transmission was not changed by bicuculline. However, TD-induced facilitation of sensory transmission to the RF boundary neuron was not observed in the presence of bicuculline. These results provide clear evidence that TD-induced plasticity in the SI cortex is mediated by the reversible suppression of lateral inhibition by GABAergic neurons.