Cholinergic effects on arousal and cocaine-induced olfactory-amygdala spindling and seizures in cats.

Effects of intravenous cholinergic and dopaminergic agents on pre-cocaine olfactory bulb (OB) spindling and behavioral arousal, and on cocaine-induced OB-amygdala spindling and behavioral seizures were evaluated in seven cats with stereotaxically implanted electrodes. Spindle data were computer analyzed using a special program for spindle detection and averaging. The number, duration and amplitude of pre-cocaine OB spindles were increased by physostigmine and decreased by atropine. Physostigmine augmented pre-cocaine behavioral arousal levels and this effect was associated with the absence of cocaine seizures. Cocaine-induced amygdala spindle number was increased by physostigmine. Changes in seizure duration following cholinergic drugs suggest cholinergic inhibitory effects. These data, in accord with previous studies showing cholinergic effects on reticulocortical arousal and seizures, suggest a cholinergic mechanism which is excitatory on OB-amygdala arousal spindling and inhibitory on cocaine-induced seizures.