Fig. 4

Inflammation and oxidative stress induce changes in axonal mitochondrial transport. a Axonal mitochondrial content does not vary after neuroinflammation or oxidative stress, although there is a slight tendency for oxidative stress to diminish mitochondrial density (Kruskal-Wallis test). b Frequency analysis of the distribution of motile and stationary mitochondrial populations shows that neuroinflammation produces an increase in stationary mitochondria and a decrease in retrograde motile mitochondria, whereas oxidative stress induces a significant increase in retrograde motile mitochondria (chi-squared test). c Neither challenge altered the size of the stationary sites with respect to the controls, yet there is a difference between both stimuli as smaller mitochondrial stationary sites are associated with neuroinflammation than with oxidative stress (Kruskal-Wallis test and Dunn’s multiple comparisons post hoc test). d, e Both stimuli dramatically decrease the mean velocity of motile mitochondria compared to the controls, even when the population of motile mitochondria is considered in terms of the orientation of the movement (Kruskal-Wallis test and Mann Whitney U test plus Bonferroni’s correction for post hoc multiple comparisons). a-e Three different experiments were performed where n = 614 control mitochondria, 444 LPS-challenged mitochondria, and 398 H₂O₂-challenged mitochondria, from 14 control axons, 9 LPS-challenged axons, and 15 H₂O₂-challenged axons: mean ± SEM. **p < 0.01, ***p < 0.001