Fig. 5

Myelin protection in adult mouse RON. a Oligodendrocyte (Nuc = nucleus) and myelinated axons (e.g., arrows) in control RON have a normal healthy structure. b, c Following OGD there is glial disruption including nuclear condensation and process degeneration (e.g., short arrows) with myelin disruption in the axon population. Note that the inner myelin layers are often separated and may form bubbles. For example in (c) (higher power image of the boxed area in (b)) where a region of myelin on the left side of the axon has five layers (small arrows) and no bubbles but the inner layer has four layers with a series of bubble profiles on the right side (e.g., *). Note retention of microtubules within the axon profile (Ax). d–f Uniform protection of myelin structure (e.g., arrows) throughout RONs fixed after OGD + QNZ-46. Note that glial cell soma (d, e) and processes (f) also retain normal structure in this protocol. g–j Myelin thickness assessed as G-ratio under the three conditions, showing myelin expansion following OGD (ANOVA with Holm−Šídák post test; P = 0.0001) and prevention of this effect by perfusion with QNZ-46 (P = 0.0007). j, k Mean data showing the changes in G-ratio under these conditions (j); which are not accounted for by significant axonal shrinking (k). l Myelin stained with fluoroMyelin (FM) under these conditions (left) and (right) the mean FM intensity decline evoked by OGD (P = 0.00027), which is prevented by MK801 (P = 0.00062). Bar a, b, e, f = 1 μm; d = 5 μm; c, l = 100 nm