Fig. 5

CCR2 deletion blocks nigral CCR2⁺ monocyte infiltration in MPTP mice but does not affect loss of DA neurons. a Quantification of the effect of CCR2 deletion on the number of CCR2-GFP⁺ cells infiltrating the SNpc of MPTP treated CCR2-GFP mice. Compared to CCR2-GFP mice with normal CCR2 content (CCR2^+/+/CCR2-GFP), CCR2 deletion in CCR2-GFP mice (CCR2^−/−/CCR2-GFP) leads to blockage of nigral infiltration of CCR2-GFP⁺ cells (measured at 24 h after MPTP intoxication). Counts represent the estimated total of CCR2-GFP⁺ cells within the entire SNpc (individual mice are shown; red bars, mean; n = 4 mice per condition; **P = 0.004, Holm-Sidak method). b Quantification of the effect of CCR2-deletion on the amount of DA neuronal loss in MPTP mice. Robust MPTP-induced death of DA neurons is measurable in both wild-type (CCR2^+/+, n = 8) and CCR2 deleted (CCR2^−/−, n = 9) mice (28 and 32%, respectively, compared to saline controls; **P = 0.002, ANOVA with Holm-Sidak test). However, CCR2 deletion does not affect MPTP-induced death of DA neurons (n.s., non-significant, P > 0.05). Counts represent the estimated total of TH⁺ DA neurons within the entire SNpc, 7 days after acute MPTP intoxication (individual mice are shown; red bar, mean)