Effect of midbrain stimulation on amphetamine-induced stereotypy in rats.
Behavioral changes were induced in rats by administration of high doses of amphetamine (5 mg/kg): among these was the development of rapid sniffing. The effect of electrical stimulation of the midbrain periaqueductal gray was then examined. This stimulation is known to release an enkephalin-like substance into the ventricular spinal fluid and to induce analgesia. Stimulation blocked amphetamine-induced sniffing. This effect was blocked in turn by pretreatment with naloxone, a specific opiate antagonist. We discuss this finding in the context of opiate-catecholamine antagonism in the CNS.
D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D004558:Electric Stimulation; D006801:Humans; D008297:Male; D008636:Mesencephalon / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013239:Stereotyped Behavior / Q000187:drug effects*
D000662:Amphetamines; D009270:Naloxone