Differential Effects of Morphine on Operant Escape Behavior and Averse Symptom Induced by Dorsal Central Gray Stimulation in Rats

• Published in: Japanese Journal of Pharmacology Vol. 55; no. 1; pp. 169 - 173
• Main Authors: Moriyama, Minehiro, Gomita, Yutaka, Ichimaru, Yasuyuki, Araki, Yasunori
• Format: Journal Article
• Language: English; Japanese
• Published: Kyoto The Japanese Pharmacological Society 1991; Japanese Pharmacological Society
• Subjects: Analgesics; Animals; Biological and medical sciences; Conditioning, Operant - drug effects; Electric Stimulation; Escape Reaction - drug effects; Male; Medical sciences; Morphine - antagonists & inhibitors; Morphine - pharmacology; Naloxone - pharmacology; Neuropharmacology; Periaqueductal Gray - physiology; Pharmacology. Drug treatments; Rats; Rats, Inbred Strains; Intraperitoneal administration; Morphine derivatives; Rat; Grey matter; Rodentia; Central nervous system; Opiates; Stimulation; Narcotic analgesic; Vertebrata; Mammalia; Instrumental behavior; Escape behavior; Animal; Mechanism of action
• ISSN: 0021-5198; 1347-3506
• DOI: 10.1016/S0021-5198(19)52083-2

The involvement of a central opiate mechanism in the operant escape behavior induced by dorsal central gray (DCG) stimulation was investigated in rats. Morphine (2-10mg/kg, i.p.) produced a rise in the DCG-stimulation threshold, but did not suppress rapid running as an averse symptom. Naloxone alone affected neither the threshold nor the averse symptom. Nevertheless, naloxone counteracted morphine-induced increments in the threshold. These results suggest that the opiate system may be indirectly involved in certain aspects of the operant escape behavior induced by the DCG-stimulation.