Figure 5.

Minocycline prevented preconditioning SNI-induced increases in regenerative capacity. A–C, Neurite outgrowth of cultured DRGs without SNI [control (CTL); A] or after SNI with infusion of PBS (B) or minocycline (mino; C) via osmotic minipumps for 7 d. The culture duration was 15 h. Scale bars, 100 μm. D, E, GAP-43 immunostaining of L5 DRGs without SNI (CTL; D) or after SNI with infusion of PBS (E) or mino (F). Scale bars, 100 μm. G, H, Quantification of the mean neurite length per neuron (G) in DRG cultures and the number of GAP-43-positive neurons per 0.1 mm² in DRG tissue sections (H). n = 3 independent experiments for neurite outgrowth assays, and n = 4 animals per group for GAP-43 neuron counting. I, ELISA of cAMP levels in DRGs obtained at 7 d after injury. n = 4 animals per group. **p < 0.01 and ***p < 0.001 by one-way ANOVA, followed by Tukey's post hoc analysis.