Axon-glia exchange of macromolecules

The periaxonal and perineurial glia of crayfish and squid are strategically situated to regulate the neuronal microenvironment. Diverse molecules rapidly traverse the periaxonal sheath and a fraction of them enters the axons from glia or the glia from axons. The significance of these intercellular exchanges has not been tested directly. However, recent reports suggest that stress proteins, which probably are synthesized by both types of glia and transferred to axons, may be essential components by which the glia directly and indirectly assist neurons in tolerating ambient stress.