Mouse retina explants after long-term culture in serum free medium

The neonatal mouse retina remains viable as an explant in serum-supplemente d growth media for more than 4 weeks. Interpretation of drug effects on thi s tissue is compromised by the enigmatic composition of the serum. We sough t to remove this ambiguity by culturing neonatal as well as late postnatal mouse retina in serum-free nutrient medium. In this study three important o bservations were made, (1) there is histotypic development of neonatal as w ell as preservation of late postnatal mouse retinal structure during long-t erm culture in serum-free medium, although the late postnatal tissue tends to show some loss of cells in the outer nuclear layer. (2) Protein expressi on in explant photoreceptor cells was similar to that in the litter-matched ones, except for green cone opsin and interphotoreceptor retinoid-binding protein. although mRNA of the latter is present at similar amounts as in ag e-matched in vivo controls. (3) Cells of the inner retina stained by antibo dies to calcium-binding proteins display some novel sprouting of processes. The results show that the mouse retina can be cultured as an explant for m ore than 4 weeks in a serum-free medium. This represents an important step forward because, (1) the possibility of interference of drug effects by unk nown serum factors has been eliminated; and (2) the spent culture medium ca n be analyzed to investigate biomolecules released by the retina in vitro. (C) 2001 Elsevier Science B.V. All rights reserved.