Alcohol abuse is a major public health problem in the United States and the rewarding and aversive effects of ethanol play an important role in the transition from use to abuse. It has proven difficult, however, to identify the relative contribution of the rewarding and aversive properties of ethanol. Moderate to high doses of ethanol consistently produce conditioned place aversion in rats. A few studies report conditioned place preference with low doses of ethanol under certain experimental conditions. This proposal will use a series of manipulations found effective in dissociating the rewarding properties of morphine and cocaine from the aversive properties of LiCl to determine which properties (aversive or rewarding) mediate avoidance of a taste cue following pairings with a range of doses of ethanol. Ethanol will be administered orally, rather than IP. This procedural change matches that used in the study of the comparison of disparate natural rewards (i.e., anticipatory contrast) and provides face validity as the oral route is the mode of ethanol self-administration in humans. In so doing, it will be possible to determine whether rats avoid intake of the taste cue when paired with ethanol and whether, as occurs with cocaine self-administration, greater avoidance of the taste cue is associated with greater ethanol self- administration. The contribution of rewarding and aversive drug properties to cue-induced craving, ethanol-induced devaluation of a natural reward, and ethanol self-administration will be identified experimentally. Accurate identification of these properties will provide insight into the addictive nature of ethanol and, thereby, will facilitate the development of more effective strategies for prevention and treatment. The proposed experiments: (I) Use intake measures and ultrasonic vocalizations to test whether ethanol-induced suppression of saccharin intake is mediated by rewarding or aversive properties. (II) Use progressive ratio to verify the rewarding properties of ethanol. (III) Test whether asymmetric ibotenic acid lesions of the gustatory thalamus and gustatory cortex will prevent ethanol-induced suppression of saccharin intake. Alcohol abuse is a major public health problem in the United States and the rewarding and aversive effects of ethanol play an important role in the transition from use to abuse. It has proven difficult, however, to identify the relative contribution of the rewarding and aversive properties of ethanol. Accurate identification of these properties will provide insight into the addictive nature of ethanol and, thereby, will facilitate the development of more effective strategies for prevention and treatment. ? ? ?
| Liu, Chuang; Showalter, John; Grigson, Patricia Sue (2009) Ethanol-induced conditioned taste avoidance: reward or aversion? Alcohol Clin Exp Res 33:522-30 |
