REGULATION OF DOPAMINE RELEASE BY PRESYNAPTIC NICOTINIC RECEPTORS IN RAT STRIATAL SLICES - EFFECT OF NICOTINE IN A LOW CONCENTRATION

Rat striatal slices were continuously superfused with 3H-tyrosine to study the effect of a low concentration of nicotine on the spontaneous release of newly synthesized 3H-dopamine (3H-DA). Nicotine (10-6M) stimulated the calcium-dependent spontaneous release of 3H-DA. This effect was prevented by nicotinic blockers such as pempidine (10-5M) and d-tubocurarine (5×10-6M). The stimulatory effect of nicotine and its blockade by pempidine were still observed in the presence of tetrodotoxin (5×10-7M). This demonstrates for the first time that a low concentration of nicotine is effective in releasing DA by acting on presynaptic nicotinic receptors located on terminals of the nigro-striatal dopaminergic neurons. © 1979.