Figure 2.

(A) Maternal immune activation (MIA) offspring exhibit increased frequency of motor stereotypies and self-directed behaviors. Left panel: When observed alone in a large cage at 10 months of age, second trimester MIA (MIA²) animals produce significantly more repetitive behaviors than control animals (CON) (**p ≤ .01). The first trimester MIA (MIA¹) offspring also produce more repetitive behaviors than control animals, but this difference does not reach statistical significance at 10 months (p = .06). Middle panel: When observed alone at 22 months of age, MIA¹ offspring produce significantly more repetitive behaviors (*p ≤ .05). Second trimester MIA animals also produce significantly more repetitive behaviors than control animals at 22 months (**p ≤ .01). Right panel: When tested at 17 months of age in the Y-maze social preference assay, MIA² treatment animals produce significantly more repetitive behaviors than control animals (**p ≤ .01). (B) Maternal immune activation offspring display decreased affiliative vocalizations. Left panel: At 22 months, MIA² offspring produce significantly fewer coo calls than control animals (**p < .01). Right panel: When observed with a novel conspecific at 24 months of age, MIA¹ offspring produce significantly fewer coo calls than control animals (*p ≤ .05). (C) Maternal immune activation offspring exhibit inappropriate interactions with unfamiliar conspecifics. Left panel: First trimester MIA offspring demonstrate inappropriate social interactions with an unfamiliar animal, as indexed by high frequency of approaching (*p <0.05) and more frequently moving within arm’s reach of the unfamiliar animal (**p < .01). Right panel: First trimester MIA offspring remained near the unfamiliar animal, as indexed by the duration of time spent in physical contact or within arm’s reach of the unfamiliar animal (*p < .05)