Human epidemiologic studies implicate exposure to infection during gestation in the etiology of neurodevelopmental disorders. Animal models of maternal immune activation (MIA) have identified the maternal immune response as the critical link between maternal infection and aberrant offspring brain and behavior development. Here we evaluate neurodevelopment of male rhesus monkeys ( Macaca mulatta ) born to MIA-treated dams ( n =14) injected with a modified form of the viral mimic, Polyinosinic:polycytidylic acid (Poly IC) at the end of the first trimester. Control dams received saline injections at the same gestational time points ( n =10) or were untreated ( n =4). MIA-treated dams exhibited a strong immune response as indexed by transient increases in sickness behavior, temperature, and inflammatory cytokines. Although offspring born to control or MIA-treated dams did not differ on measures of physical growth and early developmental milestones, the MIA-treated animals exhibited subtle changes in cognitive ...