Microglia depletion

Microglia were depleted by administering PLX5622, an inhibitor of the colony-stimulating factor 1 receptor, in the chow (Elmore et al., 2014). PLX5622 was purchased from Chemgood LLC and formulated in irradiated AIN-76A standard rodent chow by Research Diets, Inc. at 1200 ppm, equivalent to 0.2 mg/kg/day/mouse. Mice were placed on the PLX5622 diet for 3 weeks before injection of microbeads. Control animals received the standard rodent chow without the inhibitor. Microglia depletion was monitored by including a group of 6 sentinel heterozygous B6.Cx3cr1-GFP mice. Normal (undepleted) microglia were counted from 7 B6.Cx3cr1-GFP mice that had received the control diet.