Abstract

The microenvironments of the brain consist of specialized cell types that together influence physiological functions in health and pathological outcomes in disease. Despite apparent differences in the density of neurons and oligodendrocytes in various milieus, such as gray matter (GM) and white matter (WM), the extent of structural and functional heterogeneity of other resident cells remains unclear. We profiled RNA in ~500,000 nuclei from 19 tissue types across the central nervous system of the healthy adult common marmoset (Callithrix jacchus) and mapped 87 identified subclusters (including neurons, glia, and vasculature) spatially onto a 3D MRI atlas. We performed cross-species comparison, explored regulatory pathways, surveyed cellular determinants of neurological disorders, and modeled regional intercellular communication. We found spatially segregated microglia, oligodendrocyte lineage cells, and astrocytes in WM and GM. WM-glia are diverse, are enriched with genes involved in stimulus response and biomolecule modification, and interact with other resident cells more extensively than their GM counterparts. GM-glia preserve the expression of developmental morphogens into adulthood and share 6 differentially enriched transcription factors that restrict the transcriptome complexity. Our work in marmoset, an experimentally tractable animal model with >5 times more WM volume and complexity than mouse, identifies novel WM-glia subtypes and their contributions to different neurological disorders. A companion Callithrix jacchus Primate Cell Atlas (CjPCA) is available through an online portal https://cjpca.ninds.nih.gov to facilitate data exploration.