Fig. 1.

A large population of DRG macrophage after injury derive from proliferation of resident macrophages. (A) Scheme of DRG macrophage depletion protocol and time points for examination. (B) Representative images showing macrophage numbers in the DRG at the indicated time after PLX administration. IBA1(red), TUJ1(blue). (Scale bars, 50 μm.) (C) Quantification of macrophage density (IBA1⁺ cells/mm²) in DRG in CD treatment and at the indicated time after PLX treatment. N = 5(CD), 3(D1), 3(D3), 4(D7), 7(D14) and 6(D21). (D) Scheme of genetically inducible fate mapping for DRG macrophages using the Cx3cr1^CreER::Ai14 mouse and nerve injury model. (E) Representative immunostaining images showing BrdU (yellow), tdTomato (magenta), IBA1 (green) and DAPI (blue) of L4 ipsilateral DRGs from the indicated treatment groups 3 d after SNC. (Scale bars, 50 μm.) (F–K) Quantification of the percentage of the indicated cells 3 d after nerve injury in the DRGs of mice treated with CD or PLX as indicated. IBA1⁺ to DAPI⁺ cells (F), tdTomato⁺ cells to DAPI⁺ cells (G), IBA1⁺tdTomato⁺ cells to IBA1⁺cells (H), BrdU-labeled IBA1⁺tdTomato⁺ cells in IBA1⁺tdTomato⁺ cells (I), BrdU-labeled IBA1⁺tdTomato^- cells in IBA1⁺ cells (J) BrdU-unlabeled IBA1⁺tdTomato⁺ cells in IBA1⁺tdTomato⁺ cells (K). N = 6 (CD+CD) and 7 (PLX+CD), respectively. (L) Representative immunostaining images of DRG 3 d after SNC showing IBA1 (green), tdTomato (magenta), and DAPI (blue). (Scale bars, 10 μm.) (M) Quantification of the percentage of the indicated cells in the DRG 3 d after nerve injury. N = 6. The data are presented as mean ± SD. N presented as mouse number.