Figure 9.

Model for the temporal generation of the cells that form the cerebellar local circuitry. A, Summary of the time points at which vz-derived cells are preferentially marked using Ascl1^CreER GIFM. The thickness of the line indicates the relative number of each cell type marked at different time points. B, During early embryogenesis (E10.5–E13.5), Pcs and neurons of the cn are born and begin to make contacts. During mid and late embryogenesis (E13.5–P0), a population of Bg and Golgi interneurons are born. Bg migrate to their final position within the Pc layer to guide newly differentiated gcs toward the igl. Golgi interneurons and gcs within the igl then form synaptic contacts within glomeruli. During early postnatal stages (P0–P5), basket interneurons are primarily generated and contact Pc apical dendrites. Finally, during late postnatal stages (P5–P15), stellate interneurons are mainly generated and occupy the outer region of the ml, and start making contacts with Pc dendrites. Astrocytes and oligodendrocytes are generated after birth and contact their target neurons. Thus, target neurons are generated before the neurons or glia that contact them are generated.