Sl. Morutto et Gd. Phillips, Post-session intra-perifornical region quinpirole infusions retard the consolidation of an appetitive differential conditioning task, BEHAV PHARM, 10(1), 1999, pp. 113-118
We have shown previously that post-session infusions of the D2/D3 dopamine
receptor antagonist sulpiride within the perifornical region of the lateral
hypothalamus (PFH) greatly facilitated the acquisition of an appetitive di
fferential conditioning task. Here, we have examined the effects of the D2/
D3 dopamine receptor agonist quinpirole on acquisition of this task. Condit
ioning sessions consisted of an initially neutral stimulus (CS+) preceding
availability of a 10% sucrose reward (US), and a control stimulus (CS-), ne
ver associated with the US, were presented, followed by bilateral intra-PFH
infusions of quinpirole (0, 0.1, 10 nmol). The acquisition of a conditione
d approach response during the CS+ period was impaired by quinpirole admini
stration in a dose-dependent manner. No other behavioural measure,vas affec
ted. All groups subsequently acquired the conditioned approach response, fo
llowing cessation of the post-session infusion procedure. The present data
extends previous findings, suggesting that the level of activation of dopam
ine receptors in the vicinity of the PFH significantly influences the conso
lidation of appetitive Pavlovian associations. (C) 1999 Lippincott Williams
& Wilkins.