Short-term post-grafting morphological alterations of glia from an adult brain transplant.

Fragments of corpus callosum from adult rabbit have been implanted into the brain of newborn mice. Previous studies had shown that under such conditions transplant-derived astroglial cells differentiate in the host and survive for at least 2 months. The present study was devised to clarify the fate of the differentiated astrocytes present in the adult transplant by using combined ultrastructural and immunohistochemical approaches. These mature cells are shown to degenerate and die within 2 days after the implantation. Therefore, we suggest that stem cells present in adult tissue would account for the surviving population of transplant-derived glial cells.