[Macrophagic and neuroglial reactions during axonic degeneration following transection of corpus callosum: a radioautographic and ultrastructural study].

The macrophagic and neuroglial reactions occurring in the corpus callosum following transection were studied by radioautography and electron microscopy in adult rats. The animals were killed at intervals ranging from two days to three months after operation. In the lesion itself and the immediately surrounding tissues an important proliferation of hematogenous macrophages was observed. Further away from the point of severance no significant numerical increase in the neuroglia could be noted. However the accumulation of glial filaments, lipid droplets and fragments of myelin sheath in the astrocytes seems to indicate that this type of cell plays a phagocytic role. As for the oligodendrocytes, there is no evidence of their participation in phagocytosis, whereas the microglia plays an important part. In the removal of the tissue debris the role and the origin of the macrophages and the microglia are discussed, as is the share of each type of cell in the phagocytic response depending on the extent of the lesion and the degree of axonal degeneration.