Fig. 2. Morphological changes induced by ß-bungarotoxin in intoxicated primary neuronal cultures. CGNs (A,B) and cortical (C,D) neurons at 6 days in vitro or hippocampal neurons (E,F) at 15 days in vitro were examined by Nomarski optics after incubation for 1 hour in either control medium (A,C,E) or medium with 5 nM ß-BTx. Notice the presence of many bulges in the neuronal extensions of the toxin-treated samples. Scale bars, 50 µm (A-D), 10 µm (E,F). Insets are higher magnifications of the areas indicated by the square.