Electrical versus cholinergic kindling.

The present investigation was designed to test the hypothesis that cholinergic neurones may constitute a critical element in the neuronal circuitory of kindling. Chemitrodes implanted in monkey and rabbit brain enabled both electrical and chemical stimulations of limbic structures. The results indicated that only few electrical kindling stimuli produce prolonged supersensitivity to intracerebrally injected physostigmine. A subsequent electrical stimulus continues the kindling progression. The cholinergic supersensitivity persists for a long time and is only suppressed by intramuscular injections of scopolamine. These findings fit best with the hypothesis that participation of muscarinic cholinergic receptors may be an important requirement of the kindling process. It appears likely that similar types of mechanisms are involved both in chemical and electrical kindling.