Molecular and Physiological Diversity of Nicotinic Acetylcholine Receptors in the Midbrain Dopaminergic Nuclei

摘要: Nicotinic acetylcholine receptors (nAChRs) on dopaminergic (DA) and GABAergic (Gaba) projection neurons of the substantia nigra (SN) ventral tegmental area (VTA) are characterized by single-cell RT-PCR patch-clamp recordings in slices rat wild-type, beta2-/-, alpha4-/-, alpha7-/- mice. The eight nAChR subunits expressed these nuclei, alpha3-7 beta2-4, contribute to four different types nAChR-mediated currents. Most DA SN VTA express two subtypes. One is inhibited dihydro-beta-erythroidine (2 microm), alpha-conotoxin MII (10 nm), methyllycaconitine (1 nm) but does not contain alpha7 subunit; it possesses a putative alpha4alpha6alpha5(beta2)(2) composition. other subtype microm) has alpha4alpha5(beta2)(2) Gaba exhibit third with (alpha4)(2)(beta2)(3) composition, whereas have either oligomer or oligomer. fourth subtype, (alpha7)(5) homomer, encountered less than half neurons, as well VTA. Neurons nuclei thus diversity nAChRs that might differentially modulate reinforcement motor behavior.