RESUMO
We have investigated the growth and interactions between dissociated cells from different visual structures obtained from neonatal albino rats, namely, retina (R), superficial gray of the tectum (T), the lateral posterior portion of the dieneephalon (G), and occipital cortex (C). Dissociated cells obtained were either cultured separately or mixed with another cell type in 24-well plates coated with laminin. After 3 days of culture surviving cells were quantified by the MTT colorimetric microassay.The optical densities obtained from mixed cultures with cells from any two of the four types (G, R, T, C) of brain tissues were 1.3 to 3 times higher than the sum of their corresponding individual cultures except for those of G+C and T+G. Among them R+T and R+G were the most active cultures, followed by R+C and T+C. Further, condition medium from tectal cells (Tc) increased the activities of R and G for 3 and 2 times, respectively, and condition medium from retinal cells (Re) increased the activities of G and C for 1.3 and 2 times, respectively. Therefore it is suggested that neuronotrophic factors may be present in Tc and Rc.
