Short-term memory impairment following chronic alcohol consumption in rats

Abstract

Prolonged alcohol consumption (20 weeks), concomitant with adequate nutrition, was found to result in a residual short-term memory deficit after a 2-month alcohol-free period. Alcohol was administered in a liquid diet containing 35–37% ethanol-derived calories. One control group was pair-fed the same diet, except that sucrose was isocalorically substituted for ethanol. A second control group received pelleted laboratory food. After a 60-day alcohol-free period, short-term memory was assessed by training the rats on a discrete-trial temporal-alternation task in which bar presses were reinforced on alternate trials. Performance of the alternation problem was evaluated under conditions of short (20 sec) and long (50 sec) between-trial retention intervals. Although alcohol-treated-rats were relatively unimpaired when the retention interval was short, they were severely impaired with the long retention interval. In addition, the performance of alcohol-treated rats was severely disrupted when a distractor task was introduced during the short retention interval. The results were discussed relative to the similar short-term memory impairments of chronic alcoholic and alcoholic Korsakoff patients.