Authors: Pia Bäckström Petri Hyytiä
Publish Date: 2007/03/09
Volume: 192, Issue: 4, Pages: 571-580
Abstract
Wistar rats were trained to selfadminister cocaine and associate a compound stimulus light and tone with the drug under an FR4FR5S secondorder schedule of reinforcement After extinction during which neither cocaine nor the compound stimulus was available responding was reinstated by contingent presentations of the compound stimulus The effects of the intraaccumbal AMPA/kainate receptor antagonist 6cyano7nitroquinoxaline2 3dione CNQX 0 001 and 003 μg/side the NMDA antagonist d2amino5phosphonopentanoate DAP5 0 1 and 2 μg/side and the mGluR5 antagonist 2methyl6phenylethynylpyridine MPEP 0 05 and 1 μg/side on reinstatement were examined in a withinsubjects designCNQX and DAP5 attenuated cueinduced reinstatement of cocaine seeking dosedependently MPEP however decreased cocaine seeking only relative to baseline because also the saline vehicle included in the withinsubjects series of injections decreased responding possibly reflecting conditioned anhedonic effects of MPEP In additional experiments none of the antagonists attenuated locomotor activity or responding for sucrose pelletsThe results suggest that cueinduced reinstatement of cocaine seeking after a period of withdrawal from cocaine is sensitive to AMPA/kainate and NMDA receptor antagonism in the nucleus accumbens core and give further evidence for the role of the accumbal glutamate transmission in modulation of drugseeking behavior
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