Neural Retina Development in vitro

Publisher Website
Google Scholar
Abstract
Purified neuronal populations from 8-day chick embryo neural retina can be obtained on either polyornithine or highly adhesive collagen, with media containing either serum or serum-free ‘N1’ supplement. A system was developed for the morphological categorization of neuronal cells into six categories, based on cell polarities as defined by the number of sites at which neurites are seen to emerge from each cell soma. Different culture conditions could thus be quantitatively compared using as parameters not only total neuronal numbers, but also the relative contribution of each cell category to the total neuronal population. A qualitative and quantitative study of the effects of aqueous extracts from chick embryo optic lobe, telencephalon, heart or kidney on these cultured neurons was carried out. In addition to the six distinct morphological categories of process-bearing neurons mentioned above, a cell type appeared in cultures supported by optic lobe- or telencephalon-containing media on collagen, which could never be recognized under the other conditions tested. These ''G'' cells represent about 1% of the total number of neurons, and are characterized by having a very long neurite, approximately 20-fold longer than the neurites of other cell types. The appearance of G cells on collagen was the only effect of optic lobe and telencephalon that was unique to these two extracts. Both the total number of neurons and the average neurite development were higher in serum- or extract-containing cultures than in cultures supported by N1 medium alone. Moreover, sera and extracts shared the ability to render polyornithine substrata competent to support neuronal survival in serum-free medium - probably through the binding of materials to the substratum.