Spontaneous recovery and dishabituation of ethanol-reinforced responding in alcohol-preferring rats.
This study examined whether habituation, a decrease in responsiveness to a repeatedly presented stimulus, occurs to ethanol reinforcers in alcohol-preferring (P) rats. Three fundamental properties of habituation were evaluated: generality, spontaneous recovery, and dishabituation. In each experiment, P rats' lever pressing was reinforced by 10% ethanol on a variable-interval 15-s schedule during 50-min sessions. Experiment 1 evaluated the generality of habituation to repeatedly presented stimuli by using ethanol and water reinforcers. Rates of responding were higher for ethanol than they were for water. Additionally, the within-session patterns of responding differed for each reinforcer, suggesting that the pattern of responding was specific to the exact nature of the repeatedly presented reinforcer. Experiment 2 examined spontaneous recovery, an increase in responsiveness to a habituated stimulus when that stimulus is not presented for a time, by separating experimental sessions by 5 min, 2 hr, or 24 hr. Early-session rates of responding during Session 2 were slower than the corresponding rates during Session 1 when sessions were separated by 5 min or 2 hr. Response rates and within-session patterns of responding during Sessions 1 and 2 were similar when sessions were separated by 24 hr. Experiment 3 tested for dishabituation, a restoration of responsiveness following the presentation of an extraneous stimulus, by presenting a tone or a light 24 min and 55 s into the session. Rates of responding temporarily increased after the tone was presented. The results of these experiments support the idea that habituation contributes to the regulation of ethanol consumption.
Murphy
Eric S
ES
Department of Psychology, Washington State University, Pullman, WA 99164-4820, USA. afesm@uaa.alaska.edu
McSweeney
Frances K
FK
Kowal
Benjamin P
BP
McDonald
Jennifer
J
Wiediger
Roberta V
RV
D000428:Alcohol Drinking / Q000235:genetics* / Q000523:psychology*; D000818:Animals; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology*; D005793:Generalization, Psychological / Q000187:drug effects; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012054:Reinforcement, Psychology; D013395:Sucrose / Q000494:pharmacology
D002492:Central Nervous System Depressants; D000431:Ethanol; D013395:Sucrose