Nicotine and brain-stimulation reward: interactions with morphine, amphetamine and pimozide.
Using a rate-independent discrete trial method of determining thresholds for rewarding electrical intracranial stimulation in rats, we evaluated the pharmacological interaction of nicotine plus morphine, d-amphetamine, or the D2 receptor antagonist, pimozide. Both morphine and amphetamine shifted the dose-response curve for nicotine down and to the left, indicating increased efficacy and potency, respectively. Pimozide at doses that have no effect on performance and only minimal effect on brain-stimulation reward blocked the effect of nicotine. These data suggest that the same dopaminergic substrate that supports the positive reinforcing effects of other drugs of abuse also supports nicotine reward.
Huston-Lyons
D
D
Laboratory of Behavioral Pharmacology, Boston University School of Medicine, MA 02118.
Sarkar
M
M
Kornetsky
C
C
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000502:physiology*; D065127:Dopamine D2 Receptor Antagonists; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004558:Electric Stimulation; D008297:Male; D008474:Medial Forebrain Bundle / Q000033:anatomy & histology / Q000502:physiology; D009020:Morphine / Q000494:pharmacology*; D009538:Nicotine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010868:Pimozide / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D012201:Reward; D012653:Self Stimulation / Q000187:drug effects*
D065127:Dopamine D2 Receptor Antagonists; D010868:Pimozide; D009538:Nicotine; D009020:Morphine; D000661:Amphetamine