Fig. 3.
Effect of NGF on neuronal development. NGF (200 ng/ml) was added to cultures immediately after the coverslips containing the neurons were placed in multiwell dishes containing a glial monolayer. Neuronal morphology was analyzed after 18 hr. Theleft panel shows the percent of cells in each developmental stage as means for three different cultures in which 50 cells per coverslip were analyzed for four coverslips per treatment: stage 1 (filled bars), stage 2 (spotted bars), and stage 3 (striped bars). The distribution of control cells is statistically different from that of NGF-treated cells (p = 0.0001; χ2 test). The right panel shows camera lucida drawings obtained from distinct fields of typical control and NGF-treated cells and gives examples of each developmental stage.