The overarching goal of Dr. Bilbo's research is to understand the mechanisms by which the immune, endocrine, and nervous systems interact, and how these interactions influence complex behavior such as cognition and emotion. The developing brain in particular is exquisitely sensitive to both endogenous and exogenous signals, and increasing evidence suggests the immune system has a critical role in brain development and associated behavioral outcomes for the life of the individual. Notably, evidence from both animal and human studies implicates the immune system in a number of disorders with known or suspected developmental origins, including schizophrenia, anxiety/depression, and autism. A particular focus of my research is on microglia, the primary immunocompetent cells of the CNS, which are involved in multiple aspects of brain development and function. Microglia originate early in the life of the fetus and are potentially very long-lived, meaning they may have the capacity to reside in the brain for most of the life of the animal. Taken together, they have hypothesized that the developing brain is particularly sensitive to early-life immune activation and the associated risk of later-life neuropsychiatric disorders because (1) microglia are long-lived such that previously activated/functionally altered microglia (i.e. microglia exposed to an early-life immune challenge) may remain within the brain into adulthood, (2) immature microglia within the developing brain are functionally and/or immunologically different than microglia within the adult brain such that early-life immune activation can have greater consequences for neuroimmune function when compared to the adult brain, and (3) microglia and their inflammatory products are critical for normal cognitive function and behavior such that neuroimmune dysfunction results in mental health dysfunction.