Astrocytes play a key role in the development of retinal vessels by detecting hypoxia in
developing retina and secreting the hypoxia-induced angiogenic factor VEGF to induce
vessel formation. The astrocytes which play this role are themselves spreading over the
retina, just ahead of the growing vessels. To understand the mechanisms which keep
astrocytes in this strategicjust ahead'position we have studied the effects of hyperoxia and
hypoxia on astrocyte differentiation and movement in situ in neonatal rat retina and in …