Figure 2. Effects of AOE on morphological and functional properties of the AN. a, Electron microscopy showing that AOE decreases the myelin thickness (a1, a4, left), decreases the number of lamella wraps (a1, a4, right, double-arrowed lines), elongates the node of Ranvier (a2, a5, asterisks between the dotted lines) and increases the diameter of the paranodes (a2, a5, arrows). Arrows point to the paranodes identified by overlapping loops. a3, a6, Double immunolabeling of Kv1.1 (green) and Caspr2 (red) shows an elongation and a decreased width of the juxtaparanodes after AOE. Scale bars: a1 and a4 left, 1 μm; a1 and a4 right, 100 nm; a2 and a5, 1 μm; a3 and a6, 2 μm. b, Left, AOE decreases the myelin lamella number (n = 62 each, Mann–Whitney U test). b, Right, The Gaussian distribution of myelin thickness is shifted to the left after AOE (n = 450 each; unpaired t test). c, Summary histograms showing the properties of 28 (unexposed) and 62 (AOE) nodes, 56 (unexposed) and 72 (AOE) paranodes; 51 (unexposed) and 44 (AOE) juxtaparanodes. d, AOE decreases the conduction velocity along the AN as calculated by the slope of linear regressions and as shown by the increased latency per mm−1 to the CAP peak (n = 6 Unexposed r2 = 0.94; n = 7 AOE r2 = 0.8). The red dotted line points to the absence of CAP (conduction failure) for distances exceeding 1 mm. e, Modeling data show the contribution of each altered axonal domain property after AOE (c) towards the decreased conduction velocity. Data presented as mean ± SD (b, c, e) or mean ± SEM (d); *p < 0.05.