TY - JOUR T1 - Temporary Depletion of Microglia during the Early Postnatal Period Induces Lasting Sex-Dependent and Sex-Independent Effects on Behavior in Rats JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0297-16.2016 VL - 3 IS - 6 SP - ENEURO.0297-16.2016 AU - Jonathan W. VanRyzin AU - Stacey J. Yu AU - Miguel Perez-Pouchoulen AU - Margaret M. McCarthy Y1 - 2016/11/01 UR - http://www.eneuro.org/content/3/6/ENEURO.0297-16.2016.abstract N2 - Microglia are the primary immune cells of the brain and function in multiple ways to facilitate proper brain development. However, our current understanding of how these cells influence the later expression of normal behaviors is lacking. Using the laboratory rat, we administered liposomal clodronate centrally to selectively deplete microglia in the developing postnatal brain. We then assessed a range of developmental, juvenile, and adult behaviors. Liposomal clodronate treatment on postnatal days 0, 2, and 4 depleted microglia with recovery by about 10 days of age and induced a hyperlocomotive phenotype, observable in the second postnatal week. Temporary microglia depletion also increased juvenile locomotion in the open field test and decreased anxiety-like behaviors in the open field and elevated plus maze. These same rats displayed reductions in predator odor–induced avoidance behavior, but increased their risk assessment behaviors compared with vehicle-treated controls. In adulthood, postnatal microglia depletion resulted in significant deficits in male-specific sex behaviors. Using factor analysis, we identified two underlying traits—behavioral disinhibition and locomotion—as being significantly altered by postnatal microglia depletion. These findings further implicate microglia as being critically important to the development of juvenile and adult behavior. ER -