Many behavioral effects of @entity1239 result from activation of nigrostriatal and mesolimbic dopaminergic systems. @entity1239 regulates @entity935 release not only by stimulation of nicotinic @entity934 receptors (nAChRs) on @entity935 cell bodies within the substantia nigra and ventral tegmental area (SN/VTA), but also on presynaptic nAChRs located on striatal terminals. The @entity6786 subtype(s) present on both cell bodies and terminals is still a matter of controversy. The purpose of this study was to use double-labeling in situ hybridization to identify @entity6786 subunit mRNAs expressed within @entity935 neurons of the SN/VTA, by using a @entity1859 -labeled riboprobe for @entity669 hydroxylase as the @entity935 cell marker and @entity12486 -labeled riboprobes for @entity6786 subunits. The results reveal a heterogeneous population of @entity6786 subunit mRNAs within midbrain @entity935 neurons. Within the SN, almost all @entity935 neurons express alpha2, @entity1293 , @entity2263 , and @entity1093 @entity6786 mRNAs, with more than half also expressing alpha3 and alpha7 mRNAs. In contrast, less than 10% express @entity537 mRNA. Within the VTA, a similar pattern of @entity6786 subunit mRNA expression is observed except that most subunits are expressed in a slightly lower percentage of @entity935 neurons than in the SN. Within the SN, @entity1293 , @entity2263 , alpha7, and @entity537 mRNAs are also expressed in a significant number of nondopaminergic neurons, whereas within the VTA this only occurs for @entity537 . The heterogeneity in the expression of @entity6786 subunits within the SN/VTA may indicate the formation of a variety of different @entity6786 subtypes on cell bodies and terminals of the nigrostriatal and mesolimbic pathways.

Expression of neuronal nicotinic XXXX receptor subunit mRNAs within midbrain @entity935 neurons.

@entity935 :: ('MESH:D004298', 'Chemical') :: ['dopamine'] @entity1859 :: ('MESH:D004076', 'Chemical') :: ['digoxigenin'] @entity1239 :: ('MESH:D009538', 'Chemical') :: ['Nicotine', 'nicotine'] @entity1093 :: ('1934', 'Gene') :: ['beta3'] @entity537 :: ('10381', 'Gene') :: ['beta4'] @entity6786 :: ('1137', 'Gene') :: ['nAChR'] @entity12486 :: ('CHEBI:37983', 'Chemical') :: ['(35)S'] @entity1293 :: ('3476', 'Gene') :: ['alpha4', 'alpha4, alpha5, alpha6'] @entity2263 :: ('10242', 'Gene') :: ['beta2'] @entity669 :: ('CHEBI:18186', 'Chemical') :: ['tyrosine'] @entity934 :: ('MESH:D000109', 'Chemical') :: ['acetylcholine']
@entity934 :: (MESH:D000109,Chemical) :: ['acetylcholine']
