Competition between ethanol-induced reward and aversion in place conditioning.
Previous place conditioning studies in mice have shown that injection of ethanol immediately before a conditioned stimulus (CS+) produces conditioned preference, whereas injection of ethanol immediately after CS+ produces conditioned aversion. In the present experiments, we examined the learning that occurs when ethanol is injected in "ambiguous" procedures that provide the opportunity for both types of conditioning. When ethanol was given midway through the CS (Experiments 1 and 2) or both before and after the CS (Experiment 3), the direction of place conditioning was the same as when mice were exposed only to whichever contingency occurred first (a primacy effect). That is, injection of ethanol in the middle of the CS conditioned aversion, whereas injection both before and after the CS conditioned preference. Because these results support the idea that ethanol elicits both aversive and rewarding effects, they are most consistent with conditioning theories that conceptualize unconditioned stimuli (USs) as events that can activate multiple representational components.
Department of Behavioral Neurosciences L470, Oregon Health & Science University, Portland, Oregon 97239-3098, USA. cunningh@ohsu.edu
Christopher L
CL
Cunningham
Rachel
R
Smith
Carrie
C
McMullin
D000818:Animals; D001522:Behavior, Animal; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003163:Competitive Behavior / Q000187:drug effects*; D003213:Conditioning, Psychological / Q000187:drug effects*; D000431:Ethanol / Q000494:pharmacology*; D006185:Habituation, Psychophysiologic; D008297:Male; D051379:Mice; D011897:Random Allocation; D012201:Reward
D000697:Central Nervous System Stimulants; D000431:Ethanol