Additivity of nicotinic and muscarinic cholinergic stimulation of substantia nigra.
Microinjection of cholinergic agonists into the anterior substantia nigra increases behaviours for which there is a pre-existing tendency and a low current rate. Rats received microinjections of carbachol, nicotine or a combination of both into the anterior substantia nigra. Carbachol and nicotine both stimulated consumption of palatable food in a dose-dependent manner (F(3,24) = 3.99, p < 0.02 and F(3,33) = 7.07, p < 0.01 respectively). Addition of carbachol to each dose of nicotine caused a significant increase in feeding compared with nicotine alone (F(1,23) = 7.01, p < 0.015). This suggests muscarinic or nicotinic cholinergic stimulation of the anterior substantia nigra can have behaviourally similar effects and, at the doses used here, the effects of nicotinic and muscarinic stimulation are additive.
Parker
G C
GC
Department of Psychology, University of St Andrews, Scotland, UK.
Winn
P
P
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004435:Eating / Q000187:drug effects; D005731:Ganglionic Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008845:Microinjections; D009538:Nicotine / Q000494:pharmacology; D010275:Parasympathetic Nervous System / Q000187:drug effects*; D010277:Parasympathomimetics / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D013268:Stimulation, Chemical; D013378:Substantia Nigra / Q000187:drug effects*
D005731:Ganglionic Stimulants; D010277:Parasympathomimetics; D009538:Nicotine; D002217:Carbachol