Penicillin as an epileptogenic agent: effect on an isolated synapse.

Penicillin enhances the excitatory postsynaptic potential of the squid stellate ganglion. This effect suggests the hypothesis that the epileptic focus created by the topical application of penicillin to the mammalian cerebral cortex is produced by the facilitation of excitatory synaptic coupling within the preexisting positive recurrent feedback system.