Moderate Prenatal Ethanol Exposure Leads to Attention Deficits in Both Male and Female Rats.

Abstract

BACKGROUND\nAttention deficits caused by prenatal ethanol exposure (PE) are a prevalent condition in fetal alcohol spectrum disorders (FASD). Importantly, the deficits are observed in individuals with FASD who have normal IQs and show no dysmorphic facial features caused by heavy PE. These observations suggest that even moderate PE could lead to attention deficits. This possibility was investigated using a rat model in the present study.\n\n\nMETHODS\nPregnant Sprague Dawley rats were administered with ethanol (3 g/kg/day) or vehicle via intragastric gavage on gestational days 8 - 20. The blood ethanol concentration (BEC) in ethanol-treated rats was 87.7 ± 1.2 mg/dL (1 h after the gavage), similar to the BEC levels reported in other moderate PE studies in rodents. Moderate PE did not produce teratogenic effects on birth weight or litter size. The adult offspring underwent a 2-choice reaction time task.\n\n\nRESULTS\nModerate PE led to augmented action impulsivity in both sexes, indicated by more rapid response initiation and increased premature responses. More marked deficits were observed in males than in females. No increases in lapse of attention, assessed by incorrect or relatively slow responses, were observed in rats of either sex with moderate PE. In addition, no deficits in learning or motor function were detected after moderate PE. Interestingly, rats with moderate PE completed more trials than controls.\n\n\nCONCLUSIONS\nOur results confirm that moderate PE indeed leads to attention deficits in both sexes, which is demonstrated by greater action impulsivity, but not increased lapses of attention. This effect is different from that of heavy PE observed in our previous study, which is manifested as impaired action impulsivity and lapses of attention in both sexes.