Microcircuits in a folium
If we enlarge a single fold of cerebellum, or a folium, we can begin to see the organization of cell types.

molecular layer, and is nearly cell-free. Instead it is occupied mostly by axons and dendrites.

Purkinje cells, central players in the circuitry of the cerebellum.

Below the Purkinje cells is a dense layer of tiny neurons called granule cells.

Finally, in the center of each folium is the white matter, all of the axons traveling into and out of the folia.

These cell types are hooked together in stereotypical ways throughout the cerebellum.