Differential Effects of Dopamine D1 and D2 Receptor Antagonists on Conditioned Orienting Behavior in the Rat

Yea-Huey Chang ； Ruey-Ming Liao

《The Chinese Journal of Physiology》 46卷4期 (2003/12) Pp. 159-168

並列摘要

Brain dopamine (DA) systems are known to be important in regulation of behavior conditioned to appetitive stimuli. Nevertheless, despite a large body of evidence showing behavioral deficits in the operant conditioning paradigm produced by DA receptor blockade, there have been relatively few studies directly assessing behavioral changes in classical conditioning paradigm under this drug treatment. By employing an appetitive Pavlovian conditioning task, the present work investigated the effects of selective D1 and D2 receptor antagonists on the expression and acquisition of the conditioned orienting response (COR) and food-cup approach. SCH23390 (0, 0.05, and 0.10 mg/kg) and raclopride (0, 0.1, and 0.2 mg/kg) were administered via an intra-peritoneal route in a between-group design. Data from Experiment 1 showed that both SCH23390 and raclopride suppressed expression of the COR and food-cup approach, but only the impairment produced by raclopride reached a significant level. In Experiment 2, with SCH23390 being administered during the acquisition phase, the suppressed COR was completely restored in a subsequent (24 h later) drug-free session. In contrast, the suppressed COR in raclopride-pretreated groups was only partially restored. These findings support the view that the DA system plays a role in the neural substrates underlying this appetitive conditioning. In addition, D2 receptors are more likely involved in the modulation of learning process of the COR than D1 receptors.

並列關鍵字

SCH23390 ； raclopride ； appetitive Pavlovian conditioning ； associative learning ； acquisition ； expression

參考文獻

Ahveninen, J.,Kahkonen, S.,Tiitinen, H.,Pekkonen, E.,Huttunen, J.,Kaakkola, S.,Ilmoniemi, R.J.,Jaaskelainen, I.P.(2000).Suppression of transient 40-Hz auditory response by haloperidol suggests modulation of human selective attention by dopamine D2 receptors.Neurosci. Lett.292,29-32.

Anderson, K.G.,Haaren F.(2000).Effects of SCH23390 and raclopride on cocaine discrimination in male and female Wistar rats.Pharmacol. Biochem. Behav.65,671-675.

Balleine, B.W.,Mowrer, R.R. (edited),Klein, S.B.(2001).Handbook of Contemporary Learning Theories.Hillsdale, NJ:Lawrence Erlbaum Associates.

Beninger, R.J.(1989).Dissociating the effects of altered dopaminergic function on performance and learning.Brain Res. Bull.23,365-371.

Beninger, R.J.(1992).D-1 receptor involvement in reward-related learning.J. Psychopharmacol.6,34-42.