Rapid induction of Pavlovian approach to an ethanol-paired visual cue in mice
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Although many studies have shown Pavlovian conditioned approach to cues paired with natural reinforcers, it has been quite difficult to induce such behavior with drug reinforcers.
This experiment tested a novel Pavlovian procedure for inducing approach to a conditioned stimulus (CS) paired with ethanol.
Mice (NZB/B1NJ, DBA/2J) received intraperitoneal injections of ethanol (2 g/kg) immediately before 10-min exposure to a rectangular chamber that contained a distinctive visual cue (star) at one end (Paired group, CS+ trials). On alternate days, saline injection preceded apparatus exposure with no distinctive cues (CS− trials). Unpaired control mice received ethanol in the home cage 60–75 min after each CS+ trial.
NZB/B1NJ Paired group mice spent increasing amounts of time (>85% of the session) in proximity to the star, whereas Unpaired group mice did not. DBA/2J Paired group mice spent slightly more time on the star side than Unpaired group mice but did not show an acquisition curve. Postconditioning tests showed a strong preference for the star side in Paired groups from both strains after saline injection. However, only NZB/B1NJ mice showed a preference after ethanol.
This study provides the first unambiguous demonstration of Pavlovian conditioned approach to an ethanol-paired visual stimulus in the absence of any contingency between the animal’s behavior and drug exposure. This effect, which is remarkable both in terms of its magnitude and the rapidity with which it was produced (within 2–3 trials), may be related to the cue-associated craving that accompanies alcohol and drug addiction.
KeywordsEthanol Autoshaping Sign-tracking Conditioned approach Place conditioning Reward Locomotor activity Inbred mice (NZB/B1NJ, DBA/2J)
- Cardinal RN, Parkinson JA, Lachenal G, Halkerston KM, Rudarakanchana N, Hall J, Morrison CH, Howes SR, Robbins TW, Everitt BJ (2002) Effects of selective excitotoxic lesions of the nucleus accumbens core, anterior cingulate cortex, and central nucleus of the amygdala on autoshaping performance in rats. Behav Neurosci 116:553–567PubMedCrossRefGoogle Scholar
- Cunningham CL, Okorn DA, Howard CE (1997) Interstimulus interval determines whether ethanol produces conditioned place preference or aversion in mice. Anim Learn Behav 25:31–42Google Scholar
- Gremel CM, Cunningham CL (2007) Role of test activity in ethanol-induced disruption of place preference expression in mice. Psychopharmacology (in press). DOI 10.1007/s00213-006-0651-5
- Grusser SM, Wrase J, Klein S, Hermann D, Smolka MN, Ruf M, Weber-Fahr W, Flor H, Mann K, Braus DF, Heinz A (2004) Cue-induced activation of the striatum and medial prefrontal cortex is associated with subsequent relapse in abstinent alcoholics. Psychopharmacology 175:296–302PubMedCrossRefGoogle Scholar
- Hearst E, Jenkins HM (1974) Sign tracking: the stimulus-reinforcer relation and directed action. The Psychonomic Society, Austin, TXGoogle Scholar
- Ludwig AM (1988) Understanding the alcoholic’s mind: the nature of craving and how to control it. Oxford University Press, New YorkGoogle Scholar
- Tomie A, Brooks W, Zito B (1989) Sign-tracking: the search for reward. In: Klein SB, Mowrer RR (eds) Contemporary learning theories: Pavlovian conditioning and the status of traditional learning theory. Lawrence Erlbaum Associates, Publishers, Hillsdale, NJ, pp 191–223Google Scholar
- Yokel RA (1987) Intravenous self-administration: response rates, the effects of pharmacological challenges, and drug preference. In: Bozarth MA (ed) Methods of assessing the reinforcing properties of abused drugs. Springer, Berlin Heidelberg New York, pp 1–33Google Scholar