The role of Pavlovian cues in alcohol seeking in dependent and nondependent rats.

摘要

OBJECTIVE: Recent treatment approaches to substance use disorders have focused on reducing drug use by modifying drug-seeking behaviors in response to drug-associated cues. Understanding the effect of alcohol-related stimuli on alcohol-seeking responses is therefore of interest in the study of alcoholism. The present study examined the impact of ethanol- (ETOH) associated cues on selective ETOH-seeking behavior, using a Pavlovian-instrumental transfer design in groups of alcohol-dependent and nondependent rats. METHOD: Rats (N = 24) received Pavlovian conditioning in which each of two stimuli, a tone and white noise, was paired alternately with a 10% sweetened ETOH solution and a polycose-quinine solution. The rats were trained to perform two instrumental actions, with one action earning access to the sweetened ETOH and the other to the polycose-quinine. After training, half of the animals were made ETOH-dependent by intragastric administration of 36 g/kg of ETOH over 4 days, whereas the remainder received intragastric administration of an isocaloric polycose solution. On the following day, subjects were given a choice extinction test in which they were free to choose between both actions with no outcomes being delivered. During this test, the ETOH- and polycose-associated Pavlovian cues were presented to assess performance of the two instrumental actions both in the presence and absence of these stimuli. RESULTS: Pavlovian cues associated with both the ETOH or the polycose exerted a nonspecific excitatory influence on reward-seeking behavior in both nondependent and alcohol-dependent rats. CONCLUSIONS: Responses through which rats gain access to ETOH appear to be subject to the general excitatory influence of the general motivational arousal induced by reward-related cues. It appears the rats' performance did not depend on encoding the specific consequences of their actions and thus was not affected by the selective retrieval or priming of those consequences in memory.