Glomerulus (cerebellum)

[1] The cerebellar glomeruli are the first "processing station" for afferent nerve fibers entering the cerebellum.

Glomeruli are centered on the large axonal terminals of glutamatergic afferent mossy fibers.

[5] Researchers Sanford Palay and Victoria Chan-Palay noted that the sheath does not penetrate into the deeper part of the glomeruli or come into contact with the mossy fiber.

[6] The purpose of the glial sheath is still unknown, though multiple functions have been proposed, including structural support, electrophysiological insulation, and chemical equilibrium maintenance in the interstitial fluid, while creating a chemical barrier to the further outgrowth of granule and Golgi cell fibers.

Research conducted by David Eagleman suggests that the glial sheath limits the supply of extracellular calcium to regulate signaling.