Figure 9. Time course CARS microscopy of distal sciatic nerves following neurorrhaphy.

(a) At 3 days postoperatively, the myelin sheath anatomy suggests underlying structural chromatolysis and swelling of axons, continuing through day 6 (b). (c) At 9 days postoperatively, very little myelin signal is visualized as axons reach the nadir of degradation; macrophage-like cells with dark central nuclei begin to appear. (d) By 12 days postoperatively, lipid phagocytosis and possible metamorphosis of Schwann cells is observed. Double arrows denote myelin sheaths at early time points; the arrowhead denotes a macrophage-like cell at later time points.