Ultrastructural study of the cellular components of the organum vasculosum lamina terminalis of the rabbit (Oryctolagus cuniculus)

We studied the organum vasculosum of the lamina terminalis (OVLT), under the electron microscope (transmission and scanning) to determine its ultrastructural features. Two cell types are differentiated. Type I cells are typical ependymal cells bearing few cilia. Type II cells present a tanycytic morphology. The latter present a long basal process which travels from the perikarya and intermingles with other neuronal components, finally reaching the perivascular spaces where it comes into close contact with fenestrated capillaries.