FIGURE 5.

Lack of IL4 has no impact on the susceptibility toward 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurodegeneration. (A) Scheme for MPTP injections and time points used for qPCR, HPLC and immunohistochemistry. (B) Expression of IL4 in total tissue samples from substantia nigra (SN) and caudate putamen (CPu) of wild type (WT) mice 1 and 2 days after MPTP injections. qPCR results were normalized to Gapdh and are given as fold changes (n = 3 PBS, n = 3 MPTP). (C) Immunohistochemical detection of TH⁺ neurons in the SN 7 days after injections with PBS and MPTP. Scale bar indicates 300 μm. (D) Striatal dopamine levels in PBS- and MPTP-injected mice after 7 days. Equal reductions in dopamine levels were observed in both genotypes. (E) Quantification of TH⁺ neuron numbers in the SN of PBS- and MPTP-injected mice. No significant changes in neurodegeneration were detected between WT and mutant (IL4 KO) mice. (F) Immunohistochemical detection of TH⁺ neurons in the SN 90 days after injections with PBS and MPTP. (G) Striatal dopamine levels in PBS- and MPTP-injected mice after 90 days. Similar recoveries of dopamine levels were observed in WT and IL4 KO mice. (H) TH⁺ neuron numbers in the SN of PBS- and MPTP-injected mice after 90 days were not significantly different between WT and IL4 KO mice, indicating normal regeneration of mDA neurons in IL4-deficient mice. Scale bars indicate 300 μm. Data are given as mean ± SEM from at least three mice per genotype and time point. P-values derived from one-way ANOVA followed by Bonferroni’s multiple comparison post-test are ^∗p < 0.05 and ^∗∗p < 0.01.