Figure 6.

Quantitative analysis of neurofilament protein accumulation proximal and distal to the constriction site after constriction for 2 h in the presence or absence of metabolic substrates. Each column represents the mean accumulation ratio for the number of cells indicated and the error bars represent the standard deviation about the mean as described in the legend to Fig. 5. For these experiments, the L-15-based culture medium was replaced with a simpler Dulbecco's PBS-based medium with or without 0.6% glucose and 0.055% sodium pyruvate (fed and starved, respectively). The mean proximal accumulation ratio in the presence of glucose and pyruvate was lower than for axons constricted for the same period of time in L-15-based medium (Fig. 5 A) but it was, nevertheless, reduced significantly when these two substrates were omitted (P = 0.01, t test).