[Accelerated forgetting and increased proactive interference after long-term alcohol consumption in the mouse].

Abstract

Male Mice of the BALB/c strain were given a solution of 15% ethanol as its only source of fluid for 8 months. 2 months after alcohols was omitted from the diet they were tested for memory and compared to two control groups which received either an isocaloric solution of sucrose or tap water. Memory was tested by using spontaneous alternation (S.A.) in a T maze as a learning paradigm involving two forced trials (acquisition) followed by a free trial (retention). The 1st experiment was aimed at studying the spontaneous alteration rate as a function of the acquisition-test interval. It was found that for a short interval (5 min) the S.A. rate did not differ between the experimental aid control subjects but that it decreases more rapidly over time (1 h and 24 h) in alcohol treated subjects. The second experiment was aimed at determining whether this accelerated forgetting might not be explained by an excess of proactive interference. Results showed that when experimental subjects remembered for 1 h informations associated with a first acquisition, they were no longer able to remember those associated with a second acquisition when the interval between the two acquisitions was 5 h. Such proactive interference was not found in control subjects. These results suggest that, as in humans, prolonged alcohol consumption results in accelerated forgetting and increased proactive interferences.