SNI causes a reduction in AIS length in the IL, an effect that is partially reversed by metformin. SNI causes a reduction in AIS length in the IL, an effect that is partially reversed by metformin. A, Representative 40× and 100× images showing AIS staining in the IL. B, Male SNI mice had significantly shorter AISs in the ipsilateral and contralateral IL, which was confined to cortical layers 5/6. C, Female SNI mice did not show a significant reduction in AIS length in the IL. There were no changes observed in AIS length in the PrL (D) or Cg1 (E) subregions of male SNI mice. F, Gabapentin treatment had no effect on AIS length in the IL. G, Metformin treatment reversed the loss in the ipsilateral IL, but not contralateral IL, when assessed 1 d after treatment but reversed it in both hemispheres when assessed 14 d after treatment. Two-way ANOVA with Bonferroni with all groups compared with the SNI + vehicle group: **p < 0.01; *p < 0.05. Stephanie Shiers et al. J. Neurosci. 2018;38:7337-7350 ©2018 by Society for Neuroscience