Ultrastructural association of hyaluronan with rat unmyelinated nerve fibres.

A potential association between hyaluronan and unmyelinated nerve fibres in the PNS (rat skin and iris) and CNS (rat retinal inner plexiform and nerve fibre layers) was investigated at the ultrastructural level using two different hyaluronan-binding probes (link protein-gold and aggrecan-gold). Neuronal and glial cell plasma membranes, as well as the periaxonal space in between, were specifically labelled, suggesting that hyaluronan is secreted by these cells and utilized locally. Intracelluarly, weak labelling of mitochondrial profiles was observed.