Repeated Binge-Like Ethanol Administration During Adolescence cause Decreased C-Fos Immunoreactivity in Amygdala and Arcuate Nucleus in Adult Sprague-Dawley Rats

Abstract

LERMA-CABRERA, J. M.; CARVAJAL, F.; ALCARAZ-IBORRA, M.; SANCHEZ-AMATE, M. C.; DE LA FUENTE, L. & CUBERO, I. Repeated binge-like ethanol administration during adolescence cause decreased c-fos immunoreactivity in amygdala and arcuate nucleus in adult Sprague-Dawley rats. Int. J. Morphol., 32(2):575-582, 2014. SUMMARY: Binge alcohol drinking during adolescence has been associated with neurotoxicity and increased risk for the development of alcohol use disorders. There is evidence that acute and chronic ethanol administration alters c-fos expression, an indirect index of cellular activity, in different brain regions in adult rats. We evaluate here if a binge-like pattern of ethanol exposure during adolescence has a relevant impact on basal and/or ethanol-stimulated regional c-fos activity during adulthood. For that aim, Sprague-Dawley rats PND 25 were saline pre-treated, (SP group) or binge-ethanol pre-treated (BEP group) for two-consecutive days, at 48-h intervals, over a 14-day period (PND 25 to PND 38). At adult stage (PND 63) and following 25 ethanol-free days, we evaluated c-fos immunoreactivity in response to saline or acute ethanol (1.5 or 3.0 g/kg) in the hypothalamus and amygdala. We found that acute ethanol administration dose-dependently increased c-fos activity in the the Paraventricular nucleus of the hypothalamus (PVN). Interestingly, binge-ethanol exposure during adolescence significantly reduced basal c-fos activity during adulthood in the Central nucleus of the amygdala (CeA) and the Arcuate nucleus of hypothalamus (Arc). We conclude that binge-like ethanol administration during adolescence causes long-term disturbances in basal neural activity in brain areas critically involved with ethanol consumption. KEY WORDS: C-Fos; Immunoreactivity; Rats; Binge-like ethanol administration; Adolescent; Arcuate nucleus of hypothalamus (Arc); Central nucleus of the amygdala (CeA); Paraventricular nucleus of the hypothalamus (PVN).