a t-SNE showing clustering of 746 cells grafted to striatum (683 cells of hESC origin, grafted rats n = 2; 63 cells of fetal origin, grafted rats n = 2). Cell type assignments are indicated: OL oligodendrocyte, N Neuron, AC astrocyte, VLMC vascular leptomeningeal cells. b–d Expression level per cluster for indicated genes. All indicated genes are significantly enriched and established markers for astrocytes, oligodendrocytes, and pan-neuronal cells, respectively. e Expression level per cluster for selected dopaminergic markers. f Expression level per cluster for genes that are significantly enriched in the VLMC cluster and established markers for barrier-forming fibroblasts including VLMCs. g t-SNE of grafted cells as shown in Fig. 2a. Cells are marked according to their origin from either hESC-derived (red circles) or fetal-derived (blue circles) transplants. h Staining using antibodies recognizing both rat and human COL1A1 or only hCOL1A1 as indicated in the core of a hESC-derived graft from the same experiment as used for scRNA-seq. Human nuclei were counterstained with HUNU. i Representative immunofluorescence micrograph of hCOL1A1-positive cells intermingled with host-derived COL1A1-positive cells in close association with blood vessels. Boxed area shows the localization of the close-ups. j–k Representative micrographs of hCOL1A1/HUNU immunostaining from a hESC-derived graft (j) and from a fetal-derived grafts from the same experiment as used for scRNA-seq. Scale bars, 200 µM (h), 20 µM (i), and 100 µM (j, k).