beta-Endorphin induces nonconvulsive limbic seizures.

Abstract
The endogenous opioid peptide, .beta.-endorphin, induces nonconvulsive limbic epileptiform activity when administered intraventricularly to rats. Epileptiform activity is elicited by .beta.-endorphin in doses that are devoid of analgesic or behavioral signs. Equimolar intraventricular doses of morphine or of the enkephalin analog [DAla2,Met5]enkephalin-NH2 fail to elicit this limbic epileptiform activity. These observations, together with the recent immunohistochemical localization of .beta.-endorphin to midline limbic structures, suggest that .beta.-endorphin may have an important role in the regulation of limbic excitability.