Distribution of mRNA for GPR143, a receptor of 3,4-L-dihydroxyphenylalanine, and of immunoreactivities for nicotinic acetylcholine receptors in the nigrostriatal and mesolimbic regions

•We investigated the distribution of GPR143, a receptor of DOPA, and nAChR subunits.•GPR143 mRNA signals exist in the nigrostrial and mesolimbic dopaminergic systems.•In the CPu and NAc, GPR143 mRNA-positive cells are localized adjacent to TH.•In the SN and VTA, some GPR143 mRNA signals colocalize withn AChR subunit α4 or α7.•DOPA-GPR143 signaling may be involved in the nicotine action. Nicotine exerts its reinforcing actions by activating nicotinic acetylcholine receptors (nAChRs), but the detailed mechanisms remain unclear. Nicotine releases 3, 4-dihydroxyphenylalanine (DOPA), a neurotransmitter candidate in the central nervous system. Here, we investigated the distribution of GPR143, a receptor of DOPA, and nAChR subunits in the nigrostriatal and mesolimbic regions. We found GPR143 mRNA-positive cells in the striatum and nucleus accumbens. Some of them were surrounded by tyrosine hydroxylase (TH)-immunoreactive fibers. There were some GPR143 mRNA-positive cells coexpressing TH, and nAChR subunit α4 or α7 in the substantia nigra and ventral tegmental area. These findings suggest that DOPA-GPR143 signaling may be involved in the nicotine action in the nigrostriatal and mesolimbic dopaminergic systems.