Preferential stimulation of locomotor activity by ventral tegmental microinjections of (-)-nicotine.
In the present study the effect of acutely administered (-)-nicotine on locomotor activity was measured after direct bilateral microinjections into the nucleus accumbens (Acb) or into the ventral tegmental area (VTA) of rats. Intrategmental (-)-nicotine (either 0.02 or 2 micrograms/side) increased locomotor activity, the effect being greatest after the lower dose. The stimulation began almost immediately and was shortlasting with peak activity occurring at 30 min. After injection. Intra-accumbal (-)-nicotine (either 0.02, 2 or 20 micrograms/side) caused only a marginal short enhancement of activity which was not dose-dependent. The time course of enhanced activity was similar to that observed after intrategmental injection. Our results indicate that the nicotine-induced hyperlocomotion may arise primarily from activation of VTA nicotinic cholinoceptors (nAchRs), whereas activation of the accumbal nAchRs is less significant in regard to this effect.
Leikola-Pelho
T
T
Department of Pharmacology, University of Sydney, NSW, Australia.
Jackson
D M
DM
D000818:Animals; D008297:Male; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects*; D009538:Nicotine / Q000008:administration & dosage* / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013681:Tegmentum Mesencephali / Q000187:drug effects
D009538:Nicotine