Task-dependent ethanol effects on escape in rats bred for ethanol sensitivity.

Lines of rats selectively bred for differences in degree of locomotor depression by ethanol were tested for ethanol-induced impairment of jumping to a descending platform to escape 0.3 mA shock. The MA ("most affected") line showed greater decreases in height jumped than the LA ("least affected") line at IP doses of 1.25, 1.75, and 2.25, but not at 0.75 g ethanol/kg. MA rats also showed greater increases in latency to first jump (at 1.75 and 2.25 g/kg) which largely accounted for the line difference in decrease in height jumped. Males showed greater impairment than females on both measures. While extending the greater ethanol sensitivity of MA than LA rats to impairment of an escape response, the results contrast with previous studies of water escape where the LA line showed greater impairment than the MA line.