Differential effects of morphine on operant escape behavior and averse symptom induced by dorsal central gray stimulation in rats.
The involvement of a central opiate mechanism in the operant escape behavior induced by dorsal central gray (DCG) stimulation was investigated in rats. Morphine (2-10 mg/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.
Moriyama
M
M
Department of Pharmacology, Daiichi College of Pharmaceutical Sciences, Fukuoka, Japan.
Gomita
Y
Y
Ichimaru
Y
Y
Araki
Y
Y
D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D004558:Electric Stimulation; D004924:Escape Reaction / Q000187:drug effects*; D008297:Male; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D010487:Periaqueductal Gray / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains
D009270:Naloxone; D009020:Morphine