Fig. 1

Macrophages contribute to sensory recovery in the lower lip after inferior alveolar nerve (IAN) transection. A Photographs showing the rat mandibular region (top) and IAN in sham rats (middle) and inferior alveolar nerve-transected (IANX) rats (bottom). The IAN is located under the bone in the area enclosed by the solid line (top). B Time course of head withdrawal threshold (HWT) of sham and IANX rats post-surgery. n = 5, Friedman test post hoc Dunn’s test, *P < 0.05 vs. day 2. C Time course of HWT of IANX rats that were administered with control liposome (Lipo) or clodronate liposome (Clo). IANX + Lipo (n = 6); IANX + Clo (n = 7), Friedman test post hoc Dunn’s test, **P < 0.01 vs. day 2; GEE post hoc Bonferroni’s test. D Images showing IBA1 immunofluorescence at the site of IAN injury 14 day post-IANX. E Columns represent the average values of the area occupied by IBA1 immunofluorescence at the injured site. n = 5–6, one-way ANOVA post hoc Tukey’s test. **P < 0.01, ***P < 0.001. F Images showing Fluoro-Gold (FG)-labeled trigeminal ganglion (TG) neurons at 14 day post-IANX. G Columns represent the average number of FG-labeled TG neurons out of the total TG neurons. n = 5 in each, unpaired t test. **P < 0.01, ***P < 0.001. H Images showing c-Jun immunofluorescence at the injured site 14 day post-IANX. I Columns represent the average number of c-Jun-positive cells at the injured site. n = 5–7, one-way ANOVA post hoc Tukey’s test. ***P < 0.001. J Images showing c-Jun and S100β immunofluorescence at the injured site 14 day post-IANX. K Pie chart showing the percentage of c-Jun-positive cells out of S100β-positive cells at the injured site 14 day post-IANX. n = 5