A direct contact between astrocyte and vitreous body is possible in the rabbit eye due to discontinuities in the basement membrane of the retinal inner limiting membrane
AUTOR(ES)
Haddad, A., Salazar, J.J., Laicine, E.M., Ramírez, A.I., Ramírez, J.M., Triviño, A.
FONTE
Brazilian Journal of Medical and Biological Research
DATA DE PUBLICAÇÃO
2003-02
RESUMO
Different from most mammalian species, the optic nerve of the rabbit eye is initially formed inside the retina where myelination of the axons of the ganglion cells starts and vascularization occurs. Astrocytes are confined to these regions. The aforementioned nerve fibers known as medullated nerve fibers form two bundles that may be identified with the naked eye. The blood vessels run on the inner surface of these nerve fiber bundles (epivascularization) and, accordingly, the accompanying astrocytes lie mostly facing the vitreous body from which they are separated only by the inner limiting membrane of the retina. The arrangement of the astrocytes around blood vessels leads to the formation of structures known as glial tufts. Fragments (N = 3) or whole pieces (N = 3) of the medullated nerve fiber region of three-month-old male rabbits (Orictolagus cuniculus) were fixed in glutaraldehyde followed by osmium tetroxide, and their thin sections were examined with a transmission electron microscope. Randomly located discontinuities (up to a few micrometers long) of the basement membrane of the inner limiting membrane of the retina were observed in the glial tufts. As a consequence, a direct contact between the astrocyte plasma membrane and vitreous elements was demonstrated, making possible functional interactions such as macromolecular exchanges between this glial cell type and the components of the vitreous body.
Documentos Relacionados
- Changes in the retinal inner limiting membrane associated with Valsalva retinopathy
- THE INNER LIMITING MEMBRANE OF THE RETINA*
- Emigration of neural crest cells from macaque optic vesicles is correlated with discontinuities in its basement membrane.
- OBSERVATIONS ON THE HYDROGEN ION CONCENTRATION IN THE VITREOUS BODY OF THE EYE WITH REFERENCE TO GLAUCOMA
- Experimental posterior penetrating eye injury in the rabbit. II. Histology of wound, vitreous, and retina.