Laminin-immunoreactive sites are induced by growth-associated triggering factors in injured rabbit optic nerve.

We have previously demonstrated that application of soluble growth-associated triggering factors (GATFs) from regenerating fish optic nerve or neonatal rabbit optic nerve to a non-regenerative crushed adult rabbit optic nerve provokes regeneration-like changes in the adult rabbit. In this study we show that the responses initiated by GATFs also include a change in pattern of appearance of an extracellular matrix component, laminin, known to play a role in neurite outgrowth and elongation. These findings suggest a mechanism whereby GATFs activate the adult rabbit glial cells to produce or to accumulate laminin and thereby allow partial compensation for the low inherent regenerative ability of the adult rabbit optic nerve.

Effects of low-energy He-Ne laser irradiation on posttraumatic degeneration of adult rabbit optic nerve.

Axons of the mammalian peripheral and central nervous systems degenerate after nerve injury. We have recently found that He-Ne laser irradiation may prevent some of the consequences of the injury in peripheral nerves of mammals. In the present study, the efficacy of the laser in treating injured neurons of the mammalian CNS was tested. Optic nerves of adult rabbits were exposed daily for 8-14 days to He-Ne laser irradiation (14 min, 15 mW) through the overlying muscles and skin. As a result of this treatment, the injured nerves maintained their histological integrity, which is invariably lost in injured mammalian CNS neurons.

Optic nerve regeneration--new aspects.

Injury to the optic nerve and its environment provokes a process of degeneration that leads to a degenerative process resulting in an irreversible loss of visual function. We succeeded in stimulating regeneration in injured optic nerves of adult rabbits. The stimulus to regeneration was achieved by implanting in injured optic nerves of adult rabbits substances originating from growing (regenerating) optic nerves of fish or developing optic nerves of neonatal rabbits, and by delaying the degenerative process by irradiating the injured optic nerve with a low energy laser. The effect was manifested by abundant growth of new fibers across the injury site and by other manifestation of regeneration characteristics.