Figure 6.

Diversity of Adult Dopaminergic Neurons

(A) Expression of selected genes across five adult dopaminergic cell types. Colors as in (5E). ^∗, indicates selected genes for validation in (C–K). #, indicates genes selected for in situ validation from Allen Mouse Brain Atlas found in Figure S6F.

(B) Projected schematic of five distinct dopaminergic populations in adult ventral midbrain.

(C) Anterior to posterior representation of dopaminergic neuron populations at P21. Detection of CALB1, ALDH1A1, and TH. Green dots, TH⁺/ALDH1A1⁺/CALB1⁻; Yellow dots, TH⁺/ALDH1A1⁺/CALB1⁺; Red/Pink (high/low expression) dots, CALB1⁺/TH⁺/ALDH1A1⁻; White dots, TH⁺. (scale bar, 200 μm; insets, 20 μm).

(D) Validation of dopaminergic neurons at P21. Open arrow, SOX6⁺/CALB1⁻ (SNC); solid white arrow, SOX6⁺/CALB1⁺ (VTA1); solid red arrow, SOX6⁻/CALB1⁺ (VTA2-4) (scale bar left, 200 μm; right, 20 μm).

(E) Validation of dopaminergic neurons at P21. Open arrow, SOX6⁺/ALDH1A1⁺ (SNC); solid white arrow, SOX6⁻/ALDH1A1⁻ (VTA3/4); solid red arrow, SOX6⁻/ALDH1A1⁺ (VTA2) (scale bar left, 200 μm; right, 20 μm).

(F) Validation of dopaminergic neurons at P21 in posterior section. Solid white arrow VIP+/CALB1+ (VTA3) (scale bar left, 200 μm; right, 20 μm).

(G) Validation of dopaminergic neurons at P21. Open arrow, FOXA2⁻/CALB1⁺ (VTA2/4); solid white arrow, FOXA2⁺/CALB1⁺ (VTA1/3) (scale bar left, 200 μm; right, 20 μm).

(H) SOX6⁺/ALDH1A1⁺ visible at P0. Insets: open arrow, SOX6⁺/ALDH1A1⁻ (putative VTA1); solid white arrow, SOX6⁺/ALDH1A1⁺ (SNC) (scale bar, 20 μm).

(I) Absence of CALB1⁺ in TH⁺/ALDH1A1 cells at P0 (scale bar, 20 μm).

(J) CALB1⁺ (open arrow) and CALB1⁺/ALDH1A1⁺ (solid arrow, VTA2) visible at P7 (scale bar, 200 μm; insets, 20 μm).

(K) VIP⁺/CALB1⁺ (solid arrow, VTA3) visible at midline at the posterior level of P7 (scale bar, 20 μm).