Restricted expression of Rgs6 in Pitx3-positive (Pitx3+) dopaminergic neurons of ventral SNc. (A) Rgs6 expression revealed by immunohistofluorescence (red) together with TH (green) in mDA neurons of SNc but not VTA. Scale bar 410 µm. (B) Co-immunofluorescence analysis of TH (green) and Rgs6 or Pitx3 (red, as indicated) in SNc and VTA of adult mice. Arrowheads point to Pitx3-negative or Rgs6-negative mDA neurons in dorsal SNc. Scale bar 100 µm. (C) Triple immunofluorescence staining for TH (green), Pitx3 (red) and Calb1 (blue) on tissue sections of adult mice indicates that the majority of TH+Pitx3− cells of dSNc (arrowheads) are positive for Calb1, while TH+Pitx3+ cells of vSNc are negative for Calb1, consistent with depiction in A. Scale bar 100 µm.