Enzyme histochemistry of Wallerian degeneration in the immature optic nerve of rabbits.

A histochemical study was performed on the activity of several phosphatases, esterases and oxidoreductases in the immature optic nerve of rabbits undergoing Wallerian degeneration. Unilateral enucleations of the eye bulb were performed on 7 days old animals and the degenerated optic nerves were examined in rabbits, 5, 23, 63 and 173 days afterwards. The following results were obtained: 1. The reactive cells appearing in the immature optic nerve undergoing Wallerian degeneration exhibit distinctly increased activities of many hydrolytic and oxidoreductive enzymes. 2. The histoenzymic pattern of changes displayed by the reactive cells occurring in the immature, degenerating optic nerve is distinct from and bears no relation to that seen in the normally developing optic nerve. 3. The genetic formation contained in the oligodendroglial cells is not the sole factor safeguarding the transformation of immature and mature oligodendroglia into myelinating cells.