Glial repair in the cultured central nervous system of an insect

Summary

Insect glial cells are capable of division and repair in organ culture after selective damage with the toxin ethidium bromide. The repair is slower and less organised than seen in vivo after similar treatment and is still incomplete after one month. Granule-containing cells, which play an important role in the early stages of repair in vivo, are never seen in cultured connectives. This observation adds further support to the hypothesis that these cells are derived from haemocytes and that their presence is necessary for rapid and orderly repair. The uptake of ³H-thymidine into perineurial glial cells in vitro, both in control and ethidiumtreated connectives, shows that there is a considerable proliferation of cells in this region. Some uptake of thymidine is also seen in subperineurial glia but division alone cannot account for the large increase in the number of glial nuclei found at the early stages of repair in this region. Further, glial cells with diverse morphologies suggest that subpopulations are present. We conclude that cell migration from undamaged areas, as well as cell proliferation, is necessary for CNS repair in vitro.