Figure 1. Spatial transcriptomics gene expression profiles were consistent with the known transcriptional signatures of dSPNs and iSPNs.

(A) Schematic coronal section adapted from the Allen Brain Reference Atlas (image 53; 0.14 mm from bregma) depicting the striatal sampling region.

(B) Representative micrographs depicting the coronal section of striatum used for sample collection. Nuclei were visualized with Syto83 (gray), dSPNs were identified by fluorescent in situ hybridization for the D1 dopamine receptor (Drd1; aqua), and iSPNs were identified by fluorescent in situ hybridization for the adenosine A2a receptor (Adora2a; purple). White boxes in the merged micrograph demarcate the dorsomedial (DM), dorsolateral (DL), and ventrolateral (VL) striatal subregions used for sample collection. Scale bar represents 1 mm.

(C) Higher power images of the sections shown in (B). Scale bar represents 200 μm.

(D) Number of genes detected in each sample (n = 6, three striatal subregions/mouse). Each point represents an individual mouse, and bars represent means. There was an effect of striatal subregion, with the greatest number of genes detected in the ventrolateral striatum, but the number of genes detected was comparable between dSPNs and iSPNs (two-way RM ANOVA, main effect of region, F_2,20 = 12.7, p = 0.0003; main effect of cell type, F_{1, 10} = 0.9641, p = 0.3493).

(E) Volcano plot depicting genes differentially expressed in dSPNs and iSPNs collapsed across regions. Genes enriched in dSPNs (FC < −1.25, n = 39) are indicated by aqua dots, and genes enriched in iSPNs (FC > 1.25, n = 31) are indicated by purple dots (unpaired t tests with Benjamini-Hochberg correction for multiple comparisons p-adj <0.1). All other genes are represented by light gray dots.

(F) The 10 most-enriched genes in dSPNs (aqua) and iSPNs (purple), based on log₂ fold change.