Image analysis of CNS neurotrophic factor effects on neuronal survival and neurite outgrowth

We have developed a method for quantifying the effects of neurotrophic factors by using digital image processing techniques to enhance the morphometric analysis of cultured neurons. Dissociated cell cultures from rat embryonic cerebral cortex were selected as a model biological system. Binary images of neuronal neurites were extracted from gray images of cultured neurons stained with Coomassie brilliant blue. Pattern recognition techniques were used to estimate the number of neurons per culture dish and the average length of the neurites on each cell. In 4-day cultures, addition of extracts from 2-week-old rat cortices dose-dependently increased both parameters. The method proved suitable for use in bioassays of factors influencing neuronal survival and neurite promotion.