Figure 2

Adult and neonatal sensory neurons elongate by stretching, but at a slower rate than embryonic neurons. Matched phase images of axons and fluorescent images of mitochondria during normal growth of (A.) neonatal rat, and (B.) adult rat sensory neurons. C & D. The kymographs (bar 20 µm, arrow 1 hour) illustrate the advance and spreading of mitochondria along the axons in each type of neuron (see Additional files 1 and 2). E. A quantitative comparison of low velocity mitochondrial transport. The error bars in the graphs are the 95% confidence intervals.