Altered gene expression of kappa opioid system, bdnf and nociceptin system on mesolimbic brain areas after prenatal alcohol exposure.

WILLE-BILLE, ARANZA; DADARIO C.; PAUTASSI R.M.

Puerto Varas

Congreso; VIII LASBRA International meeting: Neurobiological basis of alcoholism: from molecules to behavior; 2017

Latin American Society for Biomedical Research on Alcoholism

Several experiments indicated that moderate prenatal alcohol exposure (PEE, 1-2 g/kg, gestational days 17 to 20) induces a significant, facilitatory effect on subsequent ethanol consumption in infant or adolescent rats. This effect may be the consequence of PEE enhancing or reducing the appetitive and aversive motivational effects of ethanol, respectively. The mechanisms underlying PEE effects are, however, still elusive. The endogenous opioid system has been proposed as an important target of alcohol?s actions and ethanol exposure seems to alter the developmental trajectory of opioid systems, possibly affecting the hedonic effect of ethanol. The aim of this study was to describe the effect of PEE on gene expression of mesocorticolimbic areas. Pregnant Wistar rats received daily intragastric administration of alcohol (0.0 or 2.0 g/kg). Female and male offspring were analyzed on gene expression levels of predynorphin (PDYN) and kappa opioid receptors (KOR), Brain-Derived Neurotrophic Factor (BDNF), nociceptin (NOC) and nociceptin receptor (NOP) in mesocorticolimbic areas of the brain (infants and dolescents). PEE induced enhanced gene expression levels of PDYN in Ventral Tegmental Area (VTA) during infancy and KOR in VTA and Prefrontal Cortex (PC) in both ages. Moreover, gene expression of NOC was significantly elevated in Nucleus Accumbens (NA). PEE induced elevated levels of NOP in PC, but reduced levels in VTA. Finally, VTA exhibited lower levels of BDNF in PEE rats. These results confirm that a moderate exposure to alcohol during the last days of pregnancy causes alterations on mesocorticolimbic system, that could lead to a vulnerability state and alcohol consumption.