Blockade of sensitisation-induced facilitation of appetitive conditioning by post-session intra-amygdala nafadotride.
Prior D-amphetamine experience has been reported to enhance appetitive Pavlovian conditioning. The present study assessed the involvement of the mesoamygdaloid dopamine projection in this effect. Bilateral post-session intra-amygdala infusions of the D3 dopamine receptor antagonist, L-nafadotride, or vehicle were given during acquisition of a Pavlovian association in sensitised and unsensitised rats. During these sessions, subjects received presentations of a stimulus (CS(+)) paired with 10% sucrose availability. A second stimulus (CS(-)) was also presented but never paired with sucrose. Sensitised animals infused post-session with vehicle acquired a Pavlovian conditioned approach response during CS(+) presentations more rapidly than controls, as we have shown previously. However, post-session intra-amygdala L-nafadotride selectively retarded conditioned responding to the CS(+) in both groups of animals, abolishing the difference between sensitised and unsensitised rats. These results, therefore, extend the evidence for the involvement of the mesoamygdaloid dopamine projection in Pavlovian conditioning, and the facilitation of associative learning following sensitisation.
Behavioural Neuroscience Laboratory, Department of Psychology, University of York, Heslington, York YO10 5DD, UK. g.phillips@psych.york.ac.uk
Gavin D
GD
Phillips
Catherine J
CJ
Harmer
Paul K
PK
Hitchcott
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D001066:Appetite / Q000187:drug effects*; D001245:Association Learning / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects; D009281:Naphthalenes / Q000008:administration & dosage / Q000494:pharmacology*; D011759:Pyrrolidines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D050637:Receptors, Dopamine D3
D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D018765:Dopamine Uptake Inhibitors; C493595:Drd3 protein, rat; D009281:Naphthalenes; D011759:Pyrrolidines; D050637:Receptors, Dopamine D3; C097285:nafadotride; D003913:Dextroamphetamine