Fig. 4

Monosynaptic inputs onto DR neurons in different transgenic mouse lines. a Left: Schematic of viral injections for tracing monosynaptic inputs onto DR neurons using DAT-Cre, PITX3-Cre, SERT-Cre or ePET-Cre mice. Right: Fluorescence image showing GFP-positive (GFP+) cells in the striatum before (left) and after automated segmentation by pixel intensity (middle, positive pixels in white). Segmented pixels were semi-automatically assigned to anatomical structures (right); e.g. dorsal striatum (DStr), ventral pallidum (VP), nucleus accumbens medial shell (NAcMed). Red arrow indicates a manually removed image artifact (right, scale bar: 1 mm). b Graph showing correlation between manually counted input neurons and automated segmentation procedure. c Confocal images of DR starter cell populations in DAT-Cre (top) and PITX3-Cre (bottom) mice (green: RV-∆G-GFP, red: TVA-mCherry, blue: TH; scale bars 50 µm). Bar graphs (right) show colocalization between TH and starter cells (GFP+ TVA-mCherry-positive [mCherry+] cells), TVA+ non-starter cells (GFP-negative [GFP-] mCherry+ cells), and secondary cells (GFP+ mCherry- cells). d Confocal images of DR starter cells in SERT-Cre (top) and ePET-Cre (bottom) mice (green: RV-∆G-GFP, red: TVA-mCherry, blue: TpH; scale bars 50 µm). Bar graphs (right) show colocalization between TpH and starter cells, TVA+ non-starter cells, and secondary cells. e Bar graph showing quantification of inputs onto DR neurons targeted using DAT-Cre (n = 4; dark blue), PITX3-Cre (n = 3; light blue), SERT-Cre (n = 3; red) and ePET-Cre (n = 3; orange) mice. Data are presented as a percentage of total inputs (% pixels) counted in each brain. Inset shows data pooled into anatomical subdivisions indicated by dashed gray lines (two-way ANOVA on Box-Cox transformed data for DA-targeting lines: genotype-by-region interaction, F(9,50) = 3.336, p = 0.003; striatum: DAT-Cre vs PITX3-Cre, p = 0.002; septum: DAT-Cre vs PITX3-Cre, p = 0.04; two-way ANOVA on Box-Cox transformed data for 5HT-targeting lines: main effect of region, F(9,40) = 68.71, p < 0.0001; no main effect of genotype, no genotype-by region interaction, F’s < 2.351, p’s > 0.13, no other tests significant). Error bars represent SEM, *p < 0.05. See methods for definitions of anatomical abbreviations. f Horizontal and sagittal of brain-wide inputs to DR neurons in a representative mouse from each transgenic mouse line. Colors correspond to structures shown in e. Data provided as a Source Data file