(A) The graph indicates the average number of collateral vessel connections in the brain and total number of animals for 129S1, B6, BALB/cJ, Il4rα-BALB/c WT, Il4rα-BALB/c Het, and Il4rα-BALB/c KO are 31, 37, 30, 16, 28, and 17 animals, respectively. (B) The graph shows the infarct volume for 129S1, B6, BALB/cJ, Il4rα-BALB/c WT, Il4rα-BALB/c Het, and Il4rα-BALB/c KO are 32, 32, 31, 21, 21, and 27 animals, respectively. (C, E, and G) Representative images are shown for Il4rα, wild-type (C), heterozygous KO (E), and homozygous KO strains (G). Scale bar: 1 mm. (D, F, and H) D, F, and H are three times magnified from C, E and G, respectively, and red arrowheads indicate vessel connections between the ACA and MCA. (I) The graph indicates the average number of collateral vessel connections in the brain. The total number of animals for Il4rα WT, -Het, and -KO are 19, 12, and 10 animals, respectively. (J – L) Serial brain sections (1 mm) for each genotype of Il4rα WT (J), Het (K), and KO (L) 24 h after MCAO. The infarct appears as white tissue after 2% TTC staining. Scale bar: 5 mm. (M) The graph shows the infarct volume for Il4rα WT, -Het, and -KO; 12, 20, and 14 animals, respectively. Data represent the mean ± SEM. Statistical analysis, 2-tailed Student’s t test (*** p<.001 vs. 129S1 and B6 (A and B), Il4rα WT and -Het (I and M); ### p<.001 vs. Il4rα WT (M)).