Figure 8. Normal morphology of unmyelinated and myelinated axons.

Electron microscopy of sciatic nerves of 8-week-old mice A: L1^WT, B: L1^KO, C: L1^Y1176A, D: L1¹¹⁸⁰, E: L1¹¹⁵². Schwann cells compactly ensheathe multiple unmyelinated axons in L1^WT and in all L1CD mutant mice, although L1^KO showed abnormal Remak bundles. Myelin membranes were tightly packed around large axons in L1^WT and in all L1CD mutant mice. Scale bar = 3 μm. F-G) Classification scheme of unmyelinated axons depending on the degree of ensheathment.

(a) not ensheathed; (b) partially ensheathed; (c) completely ensheathed.

H) The percentage of completely ensheathed unmyelinated axons was almost identical between L1CD mutant mice and L1^WT mice, while significantly reduced in L1^KO mice. * p <0.01, ** p < 0.005 (B-2).

I) G-ratio averages. There is no significant difference in the average g-ratio of L1CD mice compared to L1^WT mice.

J-M) Distribution of g-ratios. There is no significant difference in the distribution of g-ratio in L1CD mice compared to L1^WT mice, although L1^KO mice have a larger proportion of axons with large g-ratios. *p <0.05, **p <0.01