Conclusions
Our study thus provides a novel method to generate human brain organoids, which is promising in various applications of disease models and therapies.
Methods
Instead of applying mature organoids, we innovatively developed human brain organoids in vivo by injecting small premature organoids into corpus striatum of adult SCID mice. Two months after injection, single-cell transcriptome analysis was performed on 6131 GFP-labeled human cells from transplanted mouse brains.
Results
Eight subsets of cells (including neuronal cells expressing striatal markers) were identified in these in vivo developed organoids (IVD-organoids) by unbiased clustering. Compared with in vitro cultured human cortical organoids, we found that IVD-organoids developed more supporting cells including pericyte-like and choroid plexus cells, which are important for maintaining organoid homeostasis. Furthermore, IVD-organoids showed lower levels of cellular stress and apoptosis. Conclusions: Our study thus provides a novel method to generate human brain organoids, which is promising in various applications of disease models and therapies.