Basal neural activity in infralimbic cortex is reduced in adolescents exposed to ethanol during late gestation

FABIO M.C.; PAUTASSI RM; NIZHNIKOV ME; SPEAR, N.E.

Workshop; II International Workshop: Motivated behaviors, stress and addiction: from molecules to behavior?; 2012

Latin America Research Network in Drug Abuse

Epidemiological and pre-clinical data indicate that prenatal ethanol exposure is a risk factor for heightened alcohol use and abuse later in life. It is known that the fetus perceives the chemosensory properties of ethanol following maternal intoxication and can learn that these odor cues predict the rewarding effect of the drug, leading to heightened seeking and intake later in life. We have just observed that adolescents prenatally exposed to ethanol (PE) exhibited reduced neural activity (c-fos) in infralimbic cortex, an area associated with extinction of learned associations and inactivation. Nevertheless, in that experiment adolescents underwent substantial behavioral testing before c-fos assessment. Thus, it could be argued that this effect may be an artifact derived from the substantial manipulations experienced by the animals during behavioral tests. The aim of the present study was to analyze neural activation after PE without the confusing factor of behavioral testing. Pregnant Wistar rats were given intragastric administrations of ethanol (2 g/kg) or vehicle on gestational days 17-20. On postnatal day 37 the offspring were challenged with ethanol (2.5 or 0.0 g/kg) or remain untreated, and ninety-minutes later, the adolescent?s brains were preserved and stained for c-Fos protein expression in infralimbic cortex and nucleus accumbens (core and shell). C-fos expression remained similar across prenatal treatments in nucleus accumbens core and shell. Still, PE adolescents showed a reduced activation in infralimbic cortex, suggesting that moderate and brief prenatal ethanol exposure could result in extinction deficits during adolescence.