Efeitos comportamentais e neuroquímicos em filhotes de ratas expostas ao Etanol durante o período gestacional

Abstract

The work studied behavioral and neurochemical alterations in 21-day-old pups, from both sexes (26 g on average) born from female Wistar rats administered daily with ethanol (0.5 or 4.0 g/kg, p.o.), for 30 days before mating, and throughout their gestational period. Ethanol administration continued from delivery up to weaning. The open field, elevated plus maze and forced swimming tests were used to evaluate effects of ethanol on locomotion, anxiety and depression, respectively. Binding assays were used to identify dopaminergic (D1- and D2-like) and muscarinic (M1 plus M2) receptors. Results of the plus maze test indicated significant and dose- dependent increases in the number of entrances in the open arms and in the time of permanence in the open arms, in the prenatally ethanol-exposed offspring, as compared to controls, indicating an anxiolytic effect. In the open field test, this group presented decreases in spontaneous locomotor activity as well as in the occurrences of rearing and grooming. Offspring also showed dose-dependent increases in their immobility time in the forced swimming test, characterizing despair behavior. Decreases in the hippocampal (D2: 32%; D1: 25%) and striatal (D2: 30%; D1: 52%) dopaminergic binding were detected in ethanol-exposed offspring. On the other hand, significant increases were observed in muscarinic binding in the hippocampus (40%) as well as in the striatum (42%). This study shows evidence that in utero ethanol exposure produces a long-lasting effect on development and pharmacological characteristics of brain systems that may have important implications in behavioral and neurochemical responsiveness occurring in adulthood.