Activation by nicotine of striatal neurons receiving excitatory input fromthe substantia nigra via dopamine release

An electrophysiological study was per formed to elucidate the role of nicot inic receptors in the striatal neurons in chloral hydrate-anesthetized rats . The effects of microiontophoretic application of nicotine and other drugs were examined on the caudate nucleus (CN) neurons activated monosynaptical ly by stimulation of the substantia nigra pars compacta (SN). Application o f nicotine facilitated spontaneous firing. The nicotine-induced firing of t he CN neurons was inhibited by concomitant application of domperidone or he xamethonium. These findings suggested that nicotine enhances dopamine relea se from the SN-derived dopaminergic nerve terminals by activating the neuro ns via D2 receptors. (C) 2000 Elsevier Science B.V. All rights reserved.