Figure 5

Local hydrogen peroxide exposure inhibits axonal transport. Neurons were cultured in Xona® microfluidic chambers, which permit independent control of the fluid environment surrounding the axonal and somato-dendritic compartments. (A). Neurons were seeded in the cell body chamber. After 5–10 days, their axons extended through the microchannels and into the axon chamber. The length of microchannels (450 μm) ensures that only axons extend far enough to enter the other side. Beta3-tubulin staining (green) and MAP2 staining (red) confirmed that cell bodies and dendrites were confined in the cell body chamber and only axons extended into the axon chamber (B). Mitochondrial transport was imaged in both the cell body and axon chambers before treatment. Then hydrogen peroxide (100 μM) was added into the axon chamber. Mitochondrial transport in axon chamber was severely inhibited 90 m after hydrogen peroxide treatment while transport in cell body chamber was largely intact (C). D. Quantification showed that transport in the axonal compartment was inhibited by more than 80% (*** P < 0.001 paired student t-test). Error bar indicates standard error.