Effects of immobilization induced stress on Learned responses in rats: 1. changes in signaled-avoidance responses

Abstract

After being taught a two-way avoidance/escape response in a Shuttlebox, 13 malerats were randomly assigned to one of the following groups: 1) "stress after a perlod of rest": 22 h. after the last acquisition session, rats in this group were subjected to twohours of immobilizatton stress and then tested in the shuttle-box. A new test took place72 h. la ter. 2) "stress before a period of rest": in this group, the stressor was administe.,.ed immediately after the last acquisition session. Animals were tested alter 22 and 94h. 3) "control": no stress was administered. Results showed a stress-induced response deficit.The time course of this deficit differed between the two experimental groups, beingmore marked in group 2 during the second test, while group 2 showed a recovery duringthat test.