COMPARISON BETWEEN THE EFFECTS OF ETHANOL ACID DIAZEPAM ON SPATIAL WORKING-MEMORY IN THE RAT

The present study compared the effects of ethanol and diazepam on a ta sk that allows for the assessment of both spatial working memory and t he acquisition of spatial information within each day. During the firs t trial of each day, subjects were shown the spatial location of a foo d reward on a six-arm radial-arm maze. During nine subsequent free-cho ice trials, subjects were reinforced for returning to that same spatia l location. The location of the food reward varied across days, Thus, choosing correctly on any given trial required subjects to remember wh ere food had been received during the previous trials of that day. The effects of ethanol and diazepam on working memory were assessed by an alyzing the overall number of errors committed during the nine free-ch oice trials of each day. The effects of ethanol and diazepam on within -day acquisition were assessed by comparing the number of errors commi tted during the first three trials of each day to the number of errors committed during the last three trials of each day. Ethanol and diaze pam both produced dose-dependent increases in working memory errors, a nd both did so without impairing within-day acquisition. The results o f the present study provide further evidence of the similarities betwe en the effects of ethanol and benzodiazepine receptor agonists on lear ning and memory, and are consistent with the hypothesis that ethanol's potentiation of GABA at GABA(A) receptors contributes to the learning and memory impairments produced by ethanol.