Project description:IntroductionHuman cerebral organoids (hCOs) derived from pluripotent stem cells are very promising for the study of neurodevelopment and the investigation of the healthy or diseased brain. To help establish hCOs as a powerful research model, it is essential to perform the morphological characterization of their cellular components in depth.MethodsIn this study, we analyzed the cell types consisting of hCOs after culturing for 45 days using immunofluorescence and reverse transcriptase qualitative polymerase chain reaction (RT-qPCR) assays. We also analyzed their subcellular morphological characteristics by transmission electron microscopy (TEM).ResultsOur results show the development of proliferative zones to be remarkably similar to those found in human brain development with cells having a polarized structure surrounding a central cavity with tight junctions and cilia. In addition, we describe the presence of immature and mature migrating neurons, astrocytes, oligodendrocyte precursor cells, and microglia-like cells.DiscussionThe ultrastructural characterization presented in this study provides valuable information on the structural development and morphology of the hCO, and this information is of general interest for future research on the mechanisms that alter the cell structure or function of hCOs.
Project description:Cerebral organoids (COs) are rapidly accelerating the rate of translational neuroscience based on their potential to model complex features of the developing human brain. Several studies have examined the electrophysiological and neural network features of COs; however, no study has comprehensively investigated the developmental trajectory of electrophysiological properties in whole-brain COs and correlated these properties with developmentally-linked morphological and cellular features. Here, we profiled the neuroelectrical activities of COs over the span of five months with a multi-electrode array (MEA) platform and observed the emergence and maturation of several electrophysiologic properties, including rapid firing rates and network bursting events. To complement these analyses, we characterized the complex molecular and cellular development that give rise to these mature neuroelectrical properties with immunohistochemical and single-cell transcriptomic analyses. This integrated approach underscores the value of COs as an emerging model system of human brain development and neurological disease.
Project description:Cerebral organoids (CerOrgs) derived from human induced pluripotent stem cells (iPSCs) are a valuable tool to study human astrocytes and their interaction with neurons and microglia. The timeline of astrocyte development and maturation in this model is currently unknown and this limits the value and applicability of the model. Therefore, we generated CerOrgs from three healthy individuals and assessed astrocyte maturation after 5, 11, 19, and 37 weeks in culture. At these four time points, the astrocyte lineage was isolated based on the expression of integrin subunit alpha 6 (ITGA6). Based on the transcriptome of the isolated ITGA6-positive cells, astrocyte development started between 5 and 11 weeks in culture and astrocyte maturation commenced after 11 weeks in culture. After 19 weeks in culture, the ITGA6-positive astrocytes had the highest expression of human mature astrocyte genes, and the predicted functional properties were related to brain homeostasis. After 37 weeks in culture, a subpopulation of ITGA6-negative astrocytes appeared highlighting the heterogeneity within the astrocytes. The morphology shifted from an elongated progenitor-like morphology to the typical bushy astrocyte morphology. Based on the morphological properties, predicted functional properties, and the similarities with the human mature astrocyte transcriptome, we concluded that ITGA6+ astrocytes have developed optimally in 19-week-old CerOrgs.
Project description:The human brain has changed dramatically from other primate species, but the genetic and developmental mechanisms behind the differences remains unclear. Here we used single cell RNA sequencing based on 10X technology to explore temporal transcriptomic dynamics and cellular heterogeneity in cerebral organoids derived from human and non-human primates chimpanzee and rhesus macaque stem cells. Using cerebral organoids as a proxy of early brain development, we detect a delayed pace of human brain development relative to the other two primate species. Additional human-specific gene expression patterns resolved to different cell states through progenitors to neurons are also found. Our data provide a transcriptomic cell atlas of primate early brain development, and illustrate features that are unique to humans.
Project description:The human brain has changed dramatically from other primate species, but the genetic and developmental mechanisms behind the differences remains unclear. Here we used single cell RNA sequencing based on 10X technology to explore temporal transcriptomic dynamics and cellular heterogeneity in cerebral organoids derived from human and non-human primates chimpanzee and rhesus macaque stem cells. Using cerebral organoids as a proxy of early brain development, we detect a delayed pace of human brain development relative to the other two primate species. Additional human-specific gene expression patterns resolved to different cell states through progenitors to neurons are also found. Our data provide a transcriptomic cell atlas of primate early brain development, and illustrate features that are unique to humans.
Project description:Pluripotent stem cells (PSC) can differentiate inot any cell type of an organism. Their remarkable capability of self-organization enables the formation of three-dimensional structures that resembles miniature organs, including cerebral organoids. These organoids can recreate early steps of the human cerebral cortex development, and show great potential for modeling human diseases, particularly for those with a developmental component. This data evidences stem cell-derived cerebral organoids as a key model to study brain development and neurodevelopmental, neurodegenerative and neuropsychiatric diseases.