Fig. 6

Impact of demyelination on axonal mitochondria ATP and H₂O₂. a CARS imaging is used to visualize myelin. At week 0, before injection of LPC, most axons are myelinated. 1 week after LPC injection, axons are demyelinated and myelin debris and ovoids are observed. At week 2, thinly myelinated axons are observed in between the myelin debris (arrowheads) and at week 3, almost all axons are myelinated again, thus resembling a healthy nerve. PBS injection induces small conformational changes, but no formation of ovoids or debris. Inserts show that neuronal mitochondria remain visible throughout the whole process. b Graph showing mito-ATeam fluorescence ratio (R) in axonal mitochondria normalized on pre-demyelination values (R0) following demyelination. Following LPC injection, ATP levels are unchanged after 1 week (p = 0.085; n = 5 mice; 27 axons), decreased after 2 weeks (p = 0.019; n = 3 mice, 24 axons) and restored after 3 weeks (p = 0.491; n = 5 mice; 31 axons). PBS injection results in no significant change (p = 0.799; n = 3 mice; 23 axons). c Graph showing mito-roGFP-Orp1 fluorescence ratio (R) in axonal mitochondria normalized on pre-demyelination values (R0) following demyelination. Following LPC injection, H₂O₂ levels are increased after 1 week (p = 0.031; n = 10 mice, 17 axons), and unchanged after 2 weeks (p = 0.663; n = 5 mice, 9 axons) and after 3 weeks (p = 0.450; n = 8 mice, 13 axons). PBS injection results in no significant change (p = 0.121; n = 3 mice, 5 axons)