VENTRAL TEGMENTAL INJECTION OF NICOTINE INDUCES LOCOMOTOR-ACTIVITY AND L-DOPA RELEASE FROM NUCLEUS-ACCUMBENS

Effects of nicotine administered systemically or locally on locomotor activity and L-3,4-dihydroxyphenylalanine (L-DOPA) release were studie d using microdialysis in the nucleus accumbens of freely moving rats. The basal L-DOPA release was Ca2+-dependent and tetrodotoxin-sensitive . Systemic nicotine (1 mg/kg s.c.) increased locomotor activity and L- DOPA release preferentially in the nucleus accumbens as compared with the striatum. Injection of nicotine (30 mu g) into the ventral tegment al area increased locomotor activity and L-DOPA release from the nucle us accumbens. These increases were antagonized by prior injection of m ecamylamine into the ventral tegmental area. Nicotine induces locomoto r activity and L-DOPA release from the nucleus accumbens via nicotinic receptors in the ventral tegmental area. The release may be relevant to behavioral actions of nicotine.