Figure 3.

Ccr2^−/− mice exhibit decreased inflammatory monocyte recruitment and are protected from early motor deficits. Because Ccr2^−/− mice have few circulating inflammatory monocytes, they were used to evaluate the functional and inflammatory effects of monocytes following ICH. A, Inflammatory monocytes are significantly less abundant in Ccr2^−/− brains following either blood injection ICH or collagenase ICH. Plots are representative from day 3 blood injection ICH and are gated on CD45^hi, CD3⁻, Ly6G⁻. N = 7–9 blood injection ICH; n = 3–4 collagenase ICH. B, The majority of CCR2⁺ cells in ipsilateral control brains are inflammatory monocytes. N = 3–9. C, One day following blood injection ICH, Ccr2^−/− mice display a decreased left forelimb deficit. N = 9–15 per group. D, In the collagenase ICH model, Ccr2^−/− mice also display a decreased forelimb deficit at day 1. N = 3–5. E, Three days following blood injection ICH Ccr2^−/− mice perform better on the beam balance test, indicating that mice with fewer inflammatory monocytes have abrogated secondary injury. Horizontal lines indicate median and bars show interquartile range. N = 8–14. F, Ccr2^−/− mice have similar lymphocyte and neutrophil numbers in blood compared with littermate controls. N = 11–17. G, Ccr2^−/− mice have many fewer inflammatory monocytes and slightly fewer Ly6C⁻ monocytes in blood. N = 13–17. Error bars in A–D, F, and G indicate SEM.