No abstract

Three groups (n = 10) of rat subjects received intraperitoneal injections of Thorazine, Elavil, and isotonic saline, respectively, prior to defensive burying testing. A defensive burying test session consisted of presenting each subject with an aversive stimulus (the discharge of a flashbulb) and recording the time each subject spent in burying behavior and the height of bedding material accumulated around the aversive stimulus during the ensuing 15 min. A retention test was conducted 24 h later. During retention sessions, subjects were simply confined to the testing chamber for 15 min. One half of the subjects in each group received retention testing under the same drug-injection condition used in the original conditioning session. The remaining subjects received retention tests under noninjection conditions. During the initial testing session, Thorazine-injected subjects spent significantly less time engaged in defensive burying and accumulated significantly less bedding material than did the salineinjected subjects. On the other hand, Elavil-injected subjects spent significantly more time burying and accumulated significantly more bedding material than did the saline-injected subjects. No significant differences, either in terms of time spent in burying or height of accumulated bedding material, were observed during retention testing.

No abstract

Two groups of rats received defensive-burying testing under the effects of saline or physostigmine injection. Saline-injected animals buried more during the first (drug-state) session than did the physostigmine-injected animals. Twenty-four hours later all Ss received a retention test under the nondrug condition. Ss originally tested under the physostigmine state buried more than the saline-injected animals did.