Socially mediated alcohol preferences in adolescent rats following interactions with an intoxicated peer.

This study focuses on "passive social influences" (alcohol-related information acquired by an organism that interacts with an intoxicated counterpart) that can potentially affect alcohol preference in adolescent rats. Five experiments were conducted to investigate whether repeated social interactions with an intoxicated peer can generate alcohol-related memories that lead an animal to exhibit heightened alcohol olfactory preference patterns. Juvenile experiences with alcohol were operationalized as follows: interactions with an alcohol-intoxicated peer (Experiment 1), with an alcohol-scented cotton surrogate (Experiment 2) or with an anesthetized alcohol-intoxicated partner (Experiments 3-5). Periadolescents were then evaluated in a two-way location olfactory test where they had the opportunity to investigate a hole scented with alcohol odor or vanilla (an odorant naturally preferred by the strain of rats here utilized). Only juveniles that interacted with an alcohol-intoxicated peer were found to exhibit a significant change in alcohol odor preferences when compared to appropriate controls that interacted with a non-intoxicated peer. Alcohol odor exposure alone or interactions with an anesthetized alcohol-intoxicated peer were not sufficient to establish changes in preference for alcohol sensory cues. Results indicate that social interactions with an intoxicated peer determine heightened preference for alcohol cues in periadolescents. The establishment of this preference seems to require behavioral manifestations of the intoxicated counterpart, instead of just being dependent on an olfactory pre-exposure to alcohol cues.

Adolescent rats discriminate a mild state of ethanol intoxication likely to act as an appetitive unconditioned stimulus.

Practically no information is available in relation to the capability of the adolescent animal in terms of discriminating postabsorptive effects of ethanol. Three experiments were conducted to analyze whether young, genetically heterogeneous rats discriminate different stages of the process of intoxication exerted by a low dose (0.5 g/kg) of ethanol. An ethanol pharmacokinetic profile was first examined to select two stages within the process of ethanol intoxication that, as a function of the corresponding blood ethanol concentrations (BECs), could represent two potentially discriminable drug states. In a second experiment, sucrose was available when the BECs of rats peaked or were of a lesser magnitude (5 and 30 min postadministration time, respectively). When animals were tested under similar or different drug states relative to the training procedure, no behavioral evidence indicative of differential sucrose expectancy was obtained. In Experiment 3, rats discriminated each of the previously defined ethanol states from a non-drug state. Unexpectedly, it was also found that the pharmacological effects of the 0.5-g/kg dose of ethanol are likely to support appetitive associative learning that involves the taste of sucrose as a conditioned stimulus. The apparent positive affective components of the state of ethanol intoxication have rarely been observed in genetically heterogeneous rats with rather brief experiences with the drug's effects.