Abstract: OcjectiVe The study was to eXamine structural features of the choroid pleXus and epipleXus cells of the rat lateral ventricles. Methods Five adult male SD rats were anesthetized deeply with 6% chloral hydrate intra-peritoneal cavity and aortic perfusion with 3% polyformaldehyde and 1%glutaraldehyde,the samples of the choroid pleXus were collected and observed with scanning electron microscope( SEM)and transmission electron microscope( TEM). Results SEM showed the surface of the choroid pleXus of the rat lateral ventricles was constituted by folds or crests in a kind of parallel way,the free surface of the cells presented microvilli. There were pseudopodial projections on the surface of epipleXus cells. TEM showed that fenestrated capillaries can be seen in choroid pleXus subepithelial cells, gap junctions can be observed between epithelial cells,a lot of mitochondria and endocytosis bubbles can be seen in cytoplasm of epithelial cells. There were pseudopodial projections on the surface of epipleXus cells. Secondary lysosome can be seen in epipleXus cells. Conclusion The study showed that the fine and ultra-structural features of the choroid pleXus and epipleXus cells of the rat lateral ventricles may provide a morphological basis for further research of the physiological and pathological significance.

Key words: choroid pleXus, lateral ventricles, cellular structures, rats