Effect of intracerebral injection of pirenzepine on electroencephalography and convulsions in conscious rabbits.

Intracerebroventricular (icv) injection of pirenzepine (Pir) 2 mg.kg-1 caused EEG spike discharges, which first appeared in amygdala or hippocampus and then in midbrain reticular formation and cortex. After that rabbits developed clonic convulsions. Injection (300 micrograms) into amygdala or hippocampus also produced EEG spike discharges Hemicholinium 3 (HC-3) 50-150 micrograms.kg-1 icv inhibited the EEG spike and seizure discharges in varying degrees produced by Pir. It is suggested that Pir has a central stimulatory action which is related to cholinergic mechanism.