ETOH SELF-ADMINISTRATION IN ANTICIPATION OF NOISE STRESS IN C57BL 6J MICE/

C57BL/6J mice were studied for self-administration of ethanol (EtOH) d uring a signal period that preceded delivery of an environmental stres sor (noise) in the home cage. Animals were given 5 weeks of conditioni ng in which a 5-min period of 75-dB pulsed noise (SIGNAL) preceded a 2 0-min period of more intense, 90-dB pulsed noise (NOISE) five times da ily. EtOH (10% w/v) was then provided in a choice procedure, and drink tube contacts were monitored by computer. Mice that had received the 5 weeks of SIGNAL and NOISE pairings showed an increase in EtOH-seekin g behavior, as reflected in EtOH tube contacts during the SIGNAL perio d. The increase was significant as compared to contacts during baselin e or QUIET periods and also as compared to contacts during the same pe riod for control (Ctrl) mice that had received only the 75-dB SIGNAL d uring conditioning. A subsequent test for passive avoidance confirmed that the 75-dB SIGNAL was aversive for mice that had received noise co nditioning but not for Ctrl mice. In sum, the results were in accord w ith a priori predictions that mice would not show increased EtOH tube contacts during occurrence of intense noise itself but would show incr eased contacts during the signal that preceded noise. These results we re interpreted as preliminary evidence that C57BL/6J mice show self-ad ministration of EtOH in anticipation of an environmental stressor.