The distribution of stellate cell descending axons in the rat cerebellum: a Golgi and a combined Golgi-electron microscopical study.

Axonal descending branches of stellate cells in the molecular layer of the cerebellar cortex of the rat were studied by means of Golgi and combined Golgi-ultrastructural methods. Special attention was paid to those branches from more superficially located cell bodies. With the Golgi method, it was observed that the number of axons from stellate cells forming pericellular baskets and 'pinceaux' increases as their cell bodies come to lie deeper in the layer. With the combined Golgi-ultrastructural method, it was verified that the synaptic contacts established by these axons are identical to those of axons from basket cells, either contacting Purkinje cell bodies or lying around the axon initial segments, where they establish septate-like junctions. This overlapping of axonal territories between stellate and basket cells is in accordance with the hypothesis that these interneurons, although situated at different levels of the cerebellar molecular layer, may be genetically identical cells. Their diversity of form would depend on the cellular microenvironment present at the time of differentiation.