Safety signals can mimic responses in reducing the ulcerogenic effects of prior shock

Abstract

The severity of restraint-induced gastric ulcerations in rats may be influenced by proactive effects of earlier shock experience. Earlier experience with escapable shock offers some protection against the ulcerogenic effects of restraint stress. In this experiment, we tested the hypothesis that providing animals with safety signals during a Pavlovian conditioning session would also provide a proactive protection against restraint ulceration similar to that provided by escape responses. Animals were subjected to five daily sessions of 20 shocks before they were subjected to a single 23-h restraint stress procedure. The animals given safety signals during the conditioning sessions developed less ulceration than those subjected to random tone-shock pairings and those that were not shocked. This complements other reports of the similar properties shared by escape conditioning and safety-signal (backward) conditioning. In contrast, postrestraint corticosterone levels were higher in animals provided earlier with safety signals than they were in other groups.