Additional file 1: Figure S1. of Brain radiation injury leads to a dose- and time-dependent recruitment of peripheral myeloid cells that depends on CCR2 signaling

Effect of head shielding during bone marrow depletion on immune cell infiltration. In this bone marrow transplant experiment, one set of animals experienced total body exposure to two doses of 6 Gy, while the other set was irradiated with head shielding. Both sets of animals were injected intravenously with 4 × 106 eGFP-expressing bone marrow cells via the tail vein. Six weeks were allowed for reconstitution, and then the animals were anesthetized intravenously with a ketamine/xylazine (90 mg/kg/8 mg/kg) mixture and brought down to the irradiator in a similar manner to those animals that were cranially irradiated (sham irradiated). Animals were returned to the vivarium and sacrificed at 6 months post-anesthetization. The numbers of eGFP+ cells per square millimeter were calculated for the fimbria/fornix, the corpus callosum/extreme capsule, and the hippocampus. The average numbers of cells for section were compared using two-tailed t tests. HS = Head Shielded; TBI = Total Body Irradiated. Graph bars represent means ± SEM, n = 6 mice per condition: *p ≤ 0.05, **p ≤ 0.01, and ***p ≤ 0.001. (TIFF 2826 kb