We identified 323 neuronal subclusters across 9 regions (Data S3). Here, we illustrate systematic neuron classification using three disease-relevant nuclei of the basal ganglia (Albin et al., 1989). Neurons of the striatum have been extensively characterized, yet neurons of the globus pallidus externus (GPe) and substantia nigra reticulata (SNr) have received less attention (Figure 1 & Data S1).