Serotonin decreases population spike amplitude in hippocampal cells through a pertussis toxin substrate

Activation of the serotonin1A receptor decreases CA1 population spike amplitude and inhibits forskolin-stimulated adenylate cyclase in rat hippocampus. Pretreatment of rats with pertussis toxin blocked both responses. Because the electrophysiological and biochemical responses to serotonin were correlated after pertussis toxin treatment, we conclude that both responses are mediated by a common regulatory protein, presumably Gi.