Long-Term Analgesic Effects of Inescapable Shock and Learned Helplessness

Although exposure to inescapable shocks induced analgesia in rats, the analgesia was not manifest 24 hours later, and a brief reexposure to shock had an analgesic effect only if the rats had been shocked 24 hours previously.

Abstract

Although exposure to inescapable shocks induced analgesia in rats, the analgesia was not manifest 24 hours later. A brief reexposure to shock, however, restored the analgesia. This reexposure to shock had an analgesic effect only if the rats had been shocked 24 hours previously. Further, long-term analgesic effects depended on the controllability of the original shocks and not on shock exposure per se. Implications of these results for learned helplessness and stress-induced analgesia are discussed.