Figure 6: Alex3 protein levels regulate axonal transport of mitochondria in hippocampal neurons.

(a,c) Series of four representative confocal images, taken every 30 s, of live axons overexpressing the mitochondrial-tagged protein MitDsRed or Alex3–GFP fusion protein (a), or MitDsRed plus a control shRNAi or a specific Alex3 shRNAi (c). Coloured arrows identify the same mitochondria through the different acquisitions. (c) The upper panel identifies the imaged axon expressing GFP after infection. (b,d) Representative kymographs (two per condition) showing the full-time acquisition periods (that is, 15 min of movie) in overexpressing (c) and in silencing experiments (d). All kymographs are arranged with the distal axonal end to the right. (e,f) Graphical representation of the percentage of motile mitochondria, velocity and distance covered by individual mitochondria measured in kymographs for the overexpression (e) or silencing (f) experiments. Data were analysed using the Student's t-test and represent the mean±s.e.m of 22–42 axons (neurons) per experimental group, from at least eight independent experiments. ***P<0.001; **P<0.01; *P<0.05 (For individual P see text). Scale bars: 10 μm.