Self-administration of intravenous amphetamine: effect of nucleus accumbens CCKB receptor activation on fixed-ratio responding.
BACKGROUND
The mesolimbic dopamine (DA) system is implicated in psychostimulant drug self-administration. The neuropeptide cholecystokinin (CCK) is co-localised with DA and inhibits nucleus accumbens (NAcc) DAergic neurotransmission via CCKB receptors.


OBJECTIVE
The present experiment was designed to examine the effects of intra-NAcc CCKB receptor stimulation on fixed-ratio (FR) amphetamine self-administration.


METHODS
Wistar rats with intravenous catheters and NAcc cannulae were trained to self-administer amphetamine under a FR3 schedule of reinforcement. Animals performing stable self-administration were microinjected with pentagastrin and assessed during 3-h sessions.


RESULTS
Intra-NAcc pentagastrin dose dependently increased amphetamine intake.


CONCLUSIONS
These results are consistent with the notion that NAcc CCKB receptor activation attenuates amphetamine reward.
Bush
D E
DE
Department of Psychology, University of Toronto, Ontario, Canada.
DeSousa
N J
NJ
Vaccarino
F J
FJ
D000818:Animals; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D007267:Injections; D007275:Injections, Intravenous; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects*; D010418:Pentagastrin / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin / Q000819:agonists*; D012055:Reinforcement Schedule; D012646:Self Administration
D000697:Central Nervous System Stimulants; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin; D010418:Pentagastrin; D003913:Dextroamphetamine