EFFECTS OF ETHANOL ON NONSPATIAL WORKING-MEMORY AND ATTENTION IN RATS

Investigation into the neural basis for ethanol-induced cognitive dysf unction requires the use of valid animal models. An operant signal det ection procedure was developed to assess simultaneously the processes of sustained attention and working memory in rats, and to determine th e effects of ethanol on these cognitive functions. Ethanol, at 0.75 g/ kg ip, produced delay- and stimulus length-dependent decreases in choi ce accuracy, effects that are consistent with deficits in both working memory and sustained attention. Local infusion of ethanol directly in to the medial septal area resulted in a selective loss of choice accur acy at the long delay. The impairment by intraseptal ethanol did not i nteract with stimulus length. Thus, the working memory impairment, but not the decrement in sustained attention, was mimicked by intraseptal ethanol. The current model provides a foundation for studying the neu ral basis of ethanol's cognitive effects.