Opiate-like electroencephalographic and behavioral effects of electroconvulsive shock in rats.
Rats were studied (a) after a single transauricular electroshock (acute ECS) and (b) following 10 consecutive once-daily shocks (chronic ECS). ECS produced a generalized convulsion marked by a polyspike EEG seizure. The seizure was followed by a period of postictal depression (PID) characterized by EEG high-voltage synchrony, EMG quietening, and an associated stuporous behavior in the rat. Acute ECS produced a maximal of 33 +/- 8 (S.E.) percent above control in the EEG voltage output during postictus, with the PID lasting 2680 +/- 658 sec. Chronic ECS resulted in a significant enhancement of these acute responses. Pretreating rats with naloxone (0.3-10 mg/kg s.c.) antagonized the postictal effects of acute ECS, but not of chronic ECS. These naloxone-sensitive postictal EEG and behavioral changes appear to reflect a release of endogenous opioid peptides during ictus, a finding consistent with the hypothesis that electroshock activates opioid systems.
D000818:Animals; D001522:Behavior, Animal; D004565:Electroconvulsive Therapy; D004569:Electroencephalography; D004576:Electromyography; D004723:Endorphins / Q000502:physiology*; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000209:etiology
D004723:Endorphins; D009270:Naloxone