INJECTIONS OF 6-HYDROXYDOPAMINE INTO THE VENTRAL TEGMENTAL AREA DESTROY MESOLIMBIC DOPAMINE NEURONS BUT SPARE THE LOCOMOTOR ACTIVATING EFFECTS OF NICOTINE IN THE RAT

The locomotor response to nicotine was assessed four weeks following d estruction of mesolimbic dopamine (DA) neurons in rats by infusion of 6-hydroxydopamine into the ventral tegmental area. Resulting depletion s of nucleus accumbens (N.Acc.) DA of up to 100% of control concentrat ions did not block the acute locomotor response to nicotine (0.4 mg/kg , base, s.c.). Such depletions also did not prevent the progressive en hancement of nicotine's locomotor effects when injections were repeate d daily for nine days. These results suggest that mesolimbic DA is not necessary for the elicitation of locomotor activation by nicotine.