Bicuculline and neuronal activity in motor cortex.

We have studied the effects of bicuculline applied in microgram quantities to the precruciate gyrus (motor cortex) of cat upon visually evoked and spontaneous single-unit and slow-wave activity. The bicuculline produced an increase in both the visually evoked and the spontaneous unit activity. A surface negative component of the slow-wave response was markedly enhanced by the bicuculline. This component was associated with an intense suppression of spontaneous single-unit activity. Therefore, we have found that bicuculline has a convulsant effect upon single-unit activity as previously reported by others. However, we also found that bicuculline potentiates a process which appears associated with an enhancement of inhibition.