was a D1/D2-hybrid (D1/2) and shared many characteristics with a novel MSN type described in rodents (D1H or eccentric-SPN).15,17 Each MSN cluster was signified by groups of differentially expressed genes that were specifically enriched in that cluster (Figures 2C and 2D; Data S1; Table S1) (Methods). We used the Single Cell Clustering Assessment Framework (SCCAF) to quantify the robustness the MSN subtype clusters.27 For all nine clusters, the model predictions were robust: the areas under the receiver operating characteristic (AUROC) was more than 0.92 and 0.94, for monkeys P and F, respectively (Figure 2E and S3D).27 Together, these results indicate that the primate striatum contains at least nine transcriptionally distinct neuron subtypes that all feature characteristics of MSNs.
