Interactions between pre- and postnatal ethanol experiences: Participation of Endogenous Opioid System upon newborn and infantile responsiveness to ethanol.

MIRANDA-MORALES RS; MOLINA JC; ABATE P

Buenos Aires, Argentina

Congreso; 14th Biennial Scientific Meeting of the International Society for Comparative Psychology.; 2008

International Society of Comparative Psychology

<!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 415 0;} @font-face {font-family:Verdana; panose-1:2 11 6 4 3 5 4 4 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1593833729 1073750107 16 0 415 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman"; mso-fareast-language:ES;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Responsiveness to ethanol’s reinforcing properties, mediated by the opioid system, is affected by early experiences with the drug. In this study, we analyzed the involvement of the Opioid System in the generation of pre- and postnatal ethanol-related memories. We also evaluated alcohol self-administration in newborn and infant rats as a function of such experience. Pregnant dams received (GDs17–20) one daily administration of ethanol (0 or 2g/kg) in conjunction with naloxone (10mg/kg) or saline. On PD1, newborns were trained in an operant task (FR=1) receiving ethanol or milk as reinforcers. Yoked-controls received reinforcement with no contingence with its behavior. An extinction session was also performed. Infantile intake of ethanol (5%v/v) was assessed during PDs14 and 15. On PD14, before intake, pups received naloxone (1mg/kg) or saline; a third group remained untreated. In the operant task, animals belonging to prenatal ethanol groups and reinforced with ethanol, exhibited significantly more resistance to extinction when comparing with the remaining groups. The interaction between ethanol pre- and postnatal treatment resulted in heightened ethanol intake scores (PD15). Intake scores were diminished by naloxone administration (PD14). Nevertheless, prenatal naloxone failed to affect either, neonatal or infantile Responsiveness to the drug. These results support the hypothesis of a conditioned ethanol-preference acquired in utero. Furthermore, ethanol experiences during gestation and nursing, promote subsequent appetitive responses to the drug.