Reactive changes of glial cells after optic nerve axotomy in adult rats.

We have studied the glial response to optic nerve axotomy in vitro. Glial cells were obtained from normal and crush-axotomized optic nerves. In cultures from axotomized nerves, large numbers of astrocytes, oligodendrocyte progenitors and mature oligodendrocytes were found. Significantly fewer astrocytes and oligodendrocyte progenitors were present in cultures from normal nerves, mature oligodendrocytes did not occur. Proliferation and maturation of oligodendrocyte progenitor cells was only observed in cultures from axotomized nerves, suggesting the regulatory influence of blood-derived factors which are not present in normal nerves after in vitro axotomy. These data show that optic nerve injury enhances the ability of astrocytes, oligodendrocytes and their precursors to survive and/or proliferate in vitro.