COMPARISON OF RATS SELECTIVELY BRED FOR HIGH AND LOW ETHANOL INTAKE IN A FORCED-SWIM-TEST MODEL OF DEPRESSION - EFFECTS OF DESIPRAMINE

This investigation examined if there is a relationship between selecti ve breeding for high or low alcohol intake and immobility in a forced- swim-test (i.e., ''behavioral despair'') model of depression. Time spe nt immobile in a water-filled cylinder was measured in the alcohol-pre ferring (P) and nonpreferring (NP) lines of rats, and in the high-alco hol-drinking (HAD) and low alcohol-drinking (LAD) lines. Each rat was tested for 2 10-min trials administered 24 h apart, and pretreatment w ith saline or desipramine (10.0 or 20.0 mg desipramine/kg b.wt. IF) al so was evaluated. Drug was administered immediately after Trial I and again I h before Trial 2. When tested without pretreatment in Trial I or with saline pretreatment in Trial 2, NP rats spent significantly mo re time immobile than did P rats, but no comparable line differences w ere found when HAD and LAD rats were tested. Desipramine pretreatment reduced the time spent immobile in rats of the 2 alcohol-nonpreferring lines (i.e., the NP and LAD rats),but had no significant effect in ra ts of the 2 alcohol preferring lines (the P and HAD rats). These findi ngs do not support the hypothesis that there is a functional relations hip between high alcohol drinking and susceptibility to ''behavioral d espair'' as measured by the forced swim test. The results with desipra mine suggest that selection for high alcohol intake may be associated with insensitivity to desipramine. (C) 1997 Elsevier Science Inc.