Figure 3. Transient Schwann cell ablation causes acute demyelination followed by remyelination of the ANFs.

(a,b) Representative electron micrographs of sections through the OSL show ANF in DTA(+/−):Plp1/Cre(+/−) cochlea are demyelinated at 1 week after tamoxifen injection, followed by partial remyelination 4 weeks later and complete remyelination at 16 weeks. Arrowheads show pathological myelin sheaths and asterisks show partially re-myelinated axons. (b) Quantitative analysis of myelinated axon density in the OSL at different times after tamoxifen treatment; n=10–16 from 3 individual animals in each group. *P<0.05 and ***P<0.001 by two-way analysis of variance (ANOVA) followed by Bonferroni's post-test. (c–g) ANFs of DTA(+/−):Plp1/Cre(+/−) cochlea have normal axon caliber and myelin thickness 16 weeks after tamoxifen induction. Axonal diameter (c,e) and g-ratio (d,f,g) are normal in DTA(+/−):Plp1/Cre(+/−) cochleae 16 weeks after tamoxifen treatment. g-ratio was calculated as axon diameter / (axon+myelin sheath diameter). For e–g, n=3 animals of each group with>300 axons per group. Data are expressed as mean±s.d.