Project description:In this study, we performed single-cell RNA sequencing of E16.5 and E18.5 mouse cerebella to analyze diversity in in Purkinje cells during development.
Project description:In this study, we performed single-cell RNA sequencing of E6, E7, E8 and E9 chick cerebella to analyze diversity in in Purkinje cells during development.
Project description:The emergence of functional cerebellar circuits is heavily influenced by activity-dependent processes. However, the contribution of intrinsic Purkinje cell activity to cerebellar development remains less understood. Here, we demonstrate that before synaptic networks mature, Purkinje cell intrinsic activity is essential for regulating dendritic growth, establishing connections with cerebellar nuclei, and ensuring proper cerebellar function. Disrupting this activity during the postnatal period impairs motor function, with earlier perturbations causing more severe deficits. Importantly, only early developmental disruptions lead to pronounced defects in cellular morphology, highlighting key temporal windows for dendritic growth and maturation. Transcriptomic analyses reveal that early intrinsic activity drives the expression of activity-dependent genes, including Prkcg and Car8, which are essential for dendritic development. Our findings emphasize the importance of temporally regulated intrinsic activity in Purkinje cells in guiding cerebellar circuit development, providing a potential unifying mechanism underlying cerebellum-associated disorders.
Project description:The signalling protein PKCγ is a major regulator of Purkinje cell development and synaptic function. We have shown previously that increased PKCγ activity impairs dendritic development of cerebellar Purkinje cells. Mutations in the protein kinase Cγ gene (PRKCG) cause spinocerebellar ataxia type 14 (SCA14). In a transgenic mouse model of SCA14 expressing the human S361G mutation, Purkinje cell dendritic development is impaired in cerebellar slice cultures similar to pharmacological activation of PKC. The mechanisms of PKCγ-driven inhibition of dendritic growth are still unclear. Using immunoprecipitation-coupled mass spectrometry analysis we have identified Collapsin Response Mediator Protein 2 (CRMP2) as a protein interacting with constitutive active PKCγ(S361G) and confirmed the interaction with the Duolink™ proximity ligation assay. We show that in cerebellar slice cultures from PKCγ(S361G)- mice, phosphorylation of CRMP2 at the known PKC target site Thr555 is increased in Purkinje cells confirming phosphorylation of CRMP2 by PKCγ. miRNA-mediated CRMP2 knockdown decreased Purkinje cell dendritic outgrowth in dissociated cerebellar cultures as did the transfection of CRMP2 mutants with a modified Thr555 site. In contrast, dendritic development was normal after wildtype CRMP2 overexpression. In a novel knock-in mouse expressing only the phospho-defective T555A-mutant CRMP2, Purkinje cell dendritic development was reduced in dissociated cultures. This reduction could be rescued by transfecting wildtype CRMP2 but only partially by the phospho-mimetic T555D-mutant. Our findings establish CRMP2 as an important target of PKCγ phosphorylation in Purkinje cells mediating its control of dendritic development. Dynamic regulation of CRMP2 phosphorylation via PKCγ is required for its correct function.
Project description:We analyzed Purkinje cell transcriptome dynamics in the developing mouse cerebellum during the first three postnatal weeks, a key developmental period equivalent to the third trimester in human cerebellar development. Our study represents the first detailed analysis of developmental Purkinje cell transcriptomes and provides a valuable dataset for gene network analyses and biological questions on genes implicated in cerebellar and Purkinje cell development.
Project description:Research on human cerebellar development and disease has been hampered by the need for a human cell-based system that recapitulates the human cerebellum's cellular diversity and functional features. Here, we report a human organoid model (hCerOs) capable of developing the complex cellular diversity of the fetal cerebellum, including human-specific rhombic lip progenitor populations that have never been generated in vitro prior to this study. Two months old hCerOs form distinct cytoarchitectural features, including laminar organized layering and create functional connections between inhibitory and excitatory neurons that display coordinated network activity. Long-term culture of hCerOs allows for healthy survival and maturation of Purkinje cells that display molecular and electrophysiological hallmarks of their in vivo counterparts, addressing a long-standing challenge in the field. This study therefore provides a physiologically relevant, all-human model system to elucidate the cell type specific mechanisms governing cerebellar development and disease.
Project description:Human cerebellar development is precisely orchestrated by molecular regulatory networks. Here, we combined single-cell transcriptomics, spatial transcriptomics and chromatin accessibility states to systematically depict an integrative temporal-spatial landscape of human fetal cerebellar development. The multiomic data reveal molecular networks, providing an informative regulatory map to show how and when cell fates are determined. Spatial transcriptomics illustrated the distinct molecular signatures of the progenitors, Purkinje cells and granule cells located in different regions of the developing cerebellar cortex. We identified RORB as a new marker of developing human Purkinje cells, which was not expressed in mice. In addition, the RL progenitors highly expressed the human-specific gene ARHGAP11B , and ARHGAP11B expression led to cerebellar cortex expansion and folding in mice. We finally mapped the genes and single-nucleotide polymorphisms (SNPs) of diseases related to cerebellar dysfunction onto cell types, indicating the cellular basis and possible pathogenesis mechanisms of neuropsychiatric disorders.