Differentiation and apoptosis without DNA fragmentation in cultured Schwann cells derived from wallerian-degenerated nerve.

The Schwann cell cables provide particularly favorable sites for the growth of regenerating axonal sprouts. However, if they remain denervated, endoneurial fibrosis takes place with the Schwann cells atrophying and total Schwann cell number gradually decrease with time. Even when regenerating axonal sprouts invade into the cables, Schwann cells do not survive for long periods if they fail to make axonal contact.

Repair of nerve gap with the elongation of Wallerian degenerated nerve by tissue expansion.

We have found previously that expansion of the Wallerian degenerated nerve was accompanied by accelerated Schwann cell proliferation. In this study, we investigated the usefulness of the elongation of Wallerian degenerated nerve for the repair of short nerve gap. Male Wistar rats were used.

Expression of gp145trkB in the early stage of Schwann cell tube formation.

We investigated the expression of tyrosine kinase receptors (trkBs) and their ligand, brain-derived neurotrophic factor (BDNF), in isolated sciatic nerve segments of rat in a silicone chamber model devoid of axonal contact, using an immunohistochemical technique. The receptor gp 95trkB was not detected during the first 3 weeks but was strongly expressed in the nerve stumps on day 21. In contrast, gp 145trkB immunoreactivity was readily detected in the Schwann cells in the nerve stumps between days 1 and 7 after isolation.

Nerve expansion in nerve regeneration: effect of time on induction of ornithine decarboxylase and Schwann cell proliferation.

We studied the effect of initiation time of nerve expansion after nerve transection on the induction of ODC activity and Schwann cell proliferation in nerve tissue under Wallerian degeneration. The levels of ODC activity and Schwann cell proliferation decreased as the initiation time of nerve expansion was delayed after nerve transection, and peak levels of ODC activity following nerve expansion preceded peak levels of Schwann cell proliferation.