MILD STRESS INDUCED BY MATERNAL MANIPULATION DURING LATE GESTATION AND INFANTILE ETHANOL CONSUMPTION INDUCE CHANGES IN MU AND KAPPA OPIOID RECEPTORS, BUT NOT IN OPIOID LIGANDS PRECURSORS.

GUTTLEIN, L; MACCHIONE, A.F.; MÉNDEZ UBACH, M; MOLINA, JC; ABATE, P

Puerto Varas

Encuentro; VIII LASBRA INTERNATIONAL MEETING: Neurobiological basis of alcoholism: from molecules to behavior; 2017

Infant rats are vulnerable to ethanol?s motivational effects. Additionally, stress mediates sensitivity to ethanol?s postabsortive effects and consumption. The impact of mild stressors (i.e. maternal intubation during late gestation) remains scarcely understood during early ontogeny. This work sought to characterize changes in opioid ligands precursors and receptors gene expression in hypothalamus, after prenatal manipulation and infantile ethanol intake. Dams received an intragastric administration (i.g) of ethanol (2g/kg), water or were undisturbed, during gestational days 17-20. At postnatal days (PDs) 14-15, pups were evaluated in terms of 0% or 5% ethanol consumption. A third untreated group was added. After intake test (PD15), mRNA levels of opioid ligands precursors and receptors were measured, by real time PCR. The mRNA expression of ligand precursors did not appear to be affected by either, prenatal manipulation or postnatal intake of the drug. However, the mRNA expression of mu and kappa receptors seems to be sensible to prenatal mild stress and ethanol intake. Infantile ethanol intake seemed to up-regulate the expression of mu and kappa receptors in naïve pups. Nevertheless, ethanol consumption (PDs14-15) resulted in a down-regulation of opioid receptors when pups were exposed to mild prenatal stress. Our results suggest that the induction of a mild stress during late gestation is enough to make relatively permanent changes in mu and kappa expression on hypothalamus, when pups have the opportunity to intake the drug. This work was supported by grants from ANPCyT (PICT 2011-0130) CONICET and SECyT-UNC.