Extended Data Fig. 9 |. Analysis of striatal interneurons.

a, Clustering of an additional dataset of 2,718 marmoset striatal interneurons (acquired using 10X 3′ Chromium v.3 chemistry) confirms the existence of the large TAC3⁺ population and reveals additional diversity within the main striatal interneuron clusters. The marmoset TAC3⁺ population comprises two subtypes; markers distinguishing between the two included SULF1, ASB18, ANGPT1 and PLCXD3 (note these are also expressed at varying levels in some of the other striatal interneuron types). This dataset also identified additional markers for the TAC3⁺ population as a whole relative to other striatal interneurons, such as genes that encode the extracellular matrix protein LTBP2, corticotropin-releasing hormone receptor 2 (CRHR2), the transcriptional repressor PRDM8 and α-1D adrenergic receptor (ADRA1D). b, Scatter plots showing gene expression (log₁₀-transformed) between TAC3⁺ and PVALB⁺ or SST⁺ populations in marmoset striatum. Differentially expressed (>3-fold difference) neuropeptides and transcription factors are labelled. c, The analysis in Fig. 4a was repeated, but additionally included all mouse extra-striatal interneurons from a previous study¹⁵. For display, the t-SNE plot shows marmoset striatal interneurons (red), mouse striatal interneurons (blue) and any extra-striatal mouse interneuron that expressed Vip or Tac2 in the previously published dataset¹⁵ (grey). Circled cells indicate marmoset TAC3⁺ population. d, Liger integration of mouse and ferret striatal interneurons. Right, mouse interneurons in a mouse-only ICA-based t-SNE, with cells coloured according to their Liger clusters to confirm that clusters identified by Liger correspond meaningfully to clusters produced by a single-species analysis.