Intracortical dentate fascia grafts in the adult rat hosts. Ultrastructure of the graft/host interface.
The ultrastructure of cellular composition of the graft/host interface and its permeability for the connecting nervous fibers was investigated in the heterotopic intracortical grafts of the dentate fascia. The areas of interface, where definite border between the graft and host tissues was detected at the semithin sections, were analyzed. Three types of the graft/host interface were distinguished: i) astrocytic; ii) ependymal; and iii) perivascular. The astrocytic interface was crossed by bundles of thin unmyelinated axons (similar to the dentate mossy fibers), by fascicles of thick myelinated axons (resembling those of the neocortex), and by dendrites. Ependymal sheath, which was overdeveloped in the grafted dentate tissue, was perforated by axonal and axo-dendritic bundles, but only if they were accompanied by fibrous astrocytic processes. Wide perivascular spaces of thick-walled interface blood capillaries, where processes of perivascular glia were intermingled with numerous basal laminae, were impermeable for the nervous fibers. The data show, that extensive exchange by the nervous fibers exits between dentate and surrounding neocortex, and that various types of glial cells have different roles in supporting, or preventing development of the graft/host nervous integration.
Zhuravleva
Z N
ZN
Institute of Biophysics, USSR Academy of Sciences, Puschino-on-Oka.
D000818:Animals; D001253:Astrocytes / Q000648:ultrastructure; D016380:Brain Tissue Transplantation / Q000502:physiology*; D005260:Female; D016332:Fetal Tissue Transplantation / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology / Q000637:transplantation* / Q000648:ultrastructure; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000648:ultrastructure