Histological analyses using double-in situ hybridization of tdTom and Dat or Th mRNA and immunofluorescence of tdTOM show selective recombination in the ventral midbrain using constitutive and tamoxifen-inducible DAT-Cre mouse lines and identifies ectopic tdTOM-positive neurons in the amygdala. tdTom mRNA in coronal sections of ventral midbrain of tdTomDAT-Cre (A) and (B) tdTomDAT-CreERT2 mice 10 weeks of age. C, D, Double-FISH detecting tdTomato (red) and Dat (green) mRNA in the SNc and subregions of the VTA (IF, PBP, PN, and RLi) of the midbrain. Dat/tdTom mRNA overlap in the SNc and PBP shown in yellow (scale bar 500 μm). Higher magnification of insets of (C’–C’’’) tdTomDAT-Cre and (D’–D’’’) tdTomDAT-CreERT2 mice (scale bar: 25 μm). E, F, Double-FISH for tdTom (red) and Th (green) mRNA in the SNc and VTA with co-localization shown in yellow (scale bar: 500 μm). Higher magnification of insets of (E’–E’’’) tdTomDAT-Cre and (F’–F’’’) tdTomDAT-CreERT2 (scale bar: 25 μm). G, Immunofluorescent coronal section of ventral midbrain showing tdTOM in the SN and VTA but also in BLP (scale bar: 500 μm). tdTom, tdTomato mRNA; tdTOM, tdTomato protein; CA3, CA3 region of hippocampus; BLP, Basolateral amygdaloid nucleus posterior part; Dat, Dopamine transporter; IF, Interfascicular nucleus; PBP, Parabrachial pigmented area; PN, Paranigral nuclei; RLi, Rostral linear nucleus; SNc, Substantia nigra pars compacta; SNr, Substantia nigra pars reticulata; tdTom, tdTomato mRNA; tdTOM, tdTomato protein; Th, Tyrosine hydroxylase; VTA: Ventral tegmental area; CA3, CA3 region of hippocampus.