In vivo development and single-cell transcriptome profiling of human brain organoids in mouse corpus striatum

Human brain organoids are three-dimensional cultures that recapitulate in vivo cell diversity and organization, which provide a novel source for transplantation therapies of neurological disorders. However, some remaining technical problems including surgical lesions which still limit the application of brain organoid transplantation. Here instead of transplanting mature organoids, we performed development of organoids in vivo (IVD-organoids) by injecting small early organoids into the adult mice corpus striatum. Single-cell transcriptome analysis suggested that IVD-organoids contain pericyte-like and hippocampal cells. Similar to previous studies in cerebral organoid transplantation, IVD-organoids also showed reduced cellular stress and death. We further demonstrated that more choroid plexus (ChP) cells were generated in IVD-organoids, which were important for maintaining brain homeostasis. Together, our study provides a novel method that allows in vivo generation of human brain organoids, which may serve as a potential cell therapy for neurological disease involving different brain regions. mRNA profiles of in vivo development brain organoids at single-cell level were generated by deep sequencing