Footshock-analgesia: Prevention by behavioural manipulation but not by naloxone

Abstract

The effects of behavioural manipulation and naloxone administration on footshock-analgesia were investigated. Acute exposure of single rats to footshock resulted in a significant elevation in tail-flick latencies whilst paired animals, which fought in response to shock, did not display such analgesia. Naloxone hydrochloride (5 mg/kg), administered prior to footshock, failed to prevent the shock-induced increases in latencies. These results suggest that (a) the particular manner in which rats respond to footshock is a critical determinant of the analgesic effects of shock and (b) it is unlikely that naloxone-sensitive opiate receptors are involved in this footshock analgesia or its prevention by behavioural manipulation. © 1981.