Fig. 1.

Sensory axon growth is rudimentary in the absence of neurotrophins. Photomicrographs of neuronal cultures plated at moderate densities (2000 neurons per well) and grown for 72 hr in the presence or absence of 50 ng/ml NGF are shown.a, Neurons from Bax+/+ mice extend long, fasciculated axons in the presence of NGF.b, Neurons from Bax−/− mice in the absence of neurotrophins (no NT) extend short, branched axons that do not form fascicles. c, In the presence of NGF, cultures from Bax−/− mice look indistinguishable from controls.