Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social and communication deficits and repetitive patterns of behavior. We have previously found that male mice prenatally exposed to 600 mg/kg valproic acid (VPA) show reduced play solicitation at postnatal day 21. We hypothesized that these differences in behavior are
correlated with alterations in the activity and function of specific neuronal networks. Identification of such neurons may be relevant to our understanding of VPA effects on mouse behavior, and to ASD pathophysiology. To identify the brain structures involved in juvenile social play, we sacrificed VPA exposed and control animals 1.5h after a 30min session of play with a same-treatment, non littermate mouse. Animals were perfused with paraformaldehyde, and their brains processed for immunohistochemistry. We will analyze the expression of the early gene cFos in coronal sections throughout the brain. We will particularly focus on cFos expression in the prefrontal cortex (PFC) and the striatum, as previous reports have shown neuronal activation after social play in the anterior cingulate, prelimbic, infralimbic and orbitofrontal cortex, and in the dorsal striatum and nucleus accumbens. In addition, we will identify the type of neurons activated in each structure by co-immunofluorescence staining with the dopamine receptor 2 in the PFC and dopamine and cAMP-regulated phosphoprotein 32 (DARPP-32) in the striatum.