Fig. 5.

In vivo SRS imaging of myelin sheath degradation of a peripheral nerve after transection. (a) A branch of cranial nerve VII imaged before cutting. (b) The myelin sheath following disruption, losing its parallel structure 5 min after the cut. (c and d) 1 and 2 h after the cut, the damaged myelin can be seen to have slightly recovered. (e) Macrophages then migrated to the damaged region (red asterisk). (f) Myelin degradation starting at the distal end. (g) Myelin debris forming at both distal and proximal ends (red arrows). (h) Macrophages clearing up the myelin debris (red asterisk), and some myelin sheath is surviving following degradation (green arrows). For a better view of SRS images in the left panel, we enlarged the green rectangles about 50% to 100% in the right panel.