Behavioural responses to elevated plus-maze and defensive burying testing: effects on subsequent ethanol intake and effect of ethanol on retention of the burying response.

Based upon repeated observations of a relationship between defensive burying (DB), ethanol intake and stress ulcer susceptibility, and recurring questions regarding what DB behaviour reflects, two experiments were performed. Experiment 1 showed that prod shock exposure per se reduced subsequent ethanol intake, as did access to burying material. In rats without burying material in the conditioning phase, subsequent access to ethanol resulted in reduced DB activity in the retest, pointing to some interference by ethanol on latent learning. Experiment 2 showed that there were no effects of anxiety as measured in the elevated plus-maze (EPM) on saccharin or ethanol intake. Behaviours in the EPM and DB test did not correlate. Rats entering the open arm on first entry into the EPM drank and preferred more ethanol than those choosing the closed arm. Saccharin intake was negatively related to burying latency, and positively related to initial ethanol intake. In conclusion, it is still questionable whether the DB test is measuring anxiety, but exposure to the test or performance of the DB activity appears to cause modifications, psychologically and perhaps physiologically, in rats. Ethanol intake may under certain conditions interfere with the acquisition of a defensive response. The testing of DB behaviour may be useful in studying drug effects on latent learning of prepared responses.