Ethanol decreases choice accuracy in a radial maze delayed test.

1. The effect of acute ethanol on memory was studied in an eight-arm radial maze by interposing a 15-s or 1-h delay between the rat's fourth and fifth arm choices. 2. Ethanol (1.0 g/kg) was injected intraperitoneally 5 min prior to the first set of 4-arm choices, therefore being present since the acquisition of the trial-unique event. 3. The results showed 1) a decrease in choice accuracy only in the final 4 arm choices after the 1-h delay, and 2) that errors consisted of re-entries into arms chosen before the delay was imposed. The data further support the contention that ethanol impairs retention of working memory.