Chronic ethanol intake and object recognition in young and adult rats

Alcoholism is one of the most important problems today. Chronic alcohol intake produces many cognitive deficits in humans, especially in memory. To evaluate the memory deficits in alcoholism it is very common to use animal models. In the present work, rats receiving chronic alcohol intake and not submitted to withdrawal were evaluated in a spontaneous delayed nonmatching-to-sample test (EDNMS). Ninety-six male Wistar rats, 90 and 180 days old, were used in the experiment. Alcohol-treated rats (ALCM and ALGA) had free access to an aqueous ethanol solution as the only available liquid source from 21 days of age to the end of experiment for both groups (90 and 180 days). Animals were then evaluated in a nonspatial memory test based on the paradigm EDNMS using delays of 1, 15, and 60 min. The results show that chronic alcohol intake impairs the rats' performance, both at 90 and 180 days old, in this test of object recognition when the delay interval is of 1 h. Chronic alcohol intake with no withdrawal periods produces memory deficits and these effects of alcohol begin in the early period of intake. Moreover, we may state that the paradigm of EDNMS with a delay interval of 60 min is useful to evaluate several cognitive deficits such as hippocampal-derived memory impairment. (C) 2002 Elsevier Science Inc. All rights reserved.