Appetitive, Aversive And Negative Reinforcing Effects Of Ethanol In Infant Rats

PAUTASSI RM

Washington, DC, USA

Congreso; Joint Scientific Meeting of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism; 2008

Research Society on Alcoholism

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES-MX; mso-fareast-language:ES-MX;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> The presentation describes our current understanding of the motivational or hedonic properties of ethanol in preweanling rats. An analysis of early sensitivity to ethanol in neonates and infant rats serves as a fast, economical and highly analitical model of the effects of the drug in humans. Recent experimental evidence gathered in our lab by means of Pavlovian and operant conditioning procedures will be analyzed. Pups exhibit place aversion and reduced emission of instrumental responses when intraorally stimulated with ethanol. However, appetitive postabsorptive effects of ethanol are evident when using first- and second order tactile conditoning. Ethanol also interacts with the acquisition and expression of aversive conditioning in infants, an effect not related to GABA-A mechanisms. Specifically, ethanol devalues the representation of an aversive US and, hence, the magnitude of the conditioned aversion to this stimulus. Taken together, these results suggest that infancy in the rat is a developmental period characterized by high sensitivity to not only the aversive motivational effects of ethanol but also to its positive rewarding and negative (anti-anxiety) reinforcing capabilities.