TIGHT JUNCTIONS BETWEEN THE AXON AND SCHWANN-CELL DURING PNS REGENERATION

WE report here that during PNS regeneration, short focal tight junctio ns are present at the interface of regenerating axons and Schwann cell s in the distal part of the transected nerve. When regrowing axons wer e seen in the distal segment, focal fusions of axonal and Schwann cell membranes were observed on electron microscopy. Freeze-fracture study showed short arrays of intramembrane particles in the contacting memb rane of axons and Schwann cells. Immunohistochemical study revealed th e localization of ZO-1 tight junction associated protein at discrete s ites of axon-Schwann cell contact. These results suggest that mechanic al links of the axon and Schwann cell by means of short tight junction s are involved in axon-Schwann cell contact events during PNS regenera tion.