The Effects of Fastigial Nuclei Inactivation on Social Behavior in the Rat

Research has implicated the cerebellar deep nuclei in autism. This study questioned whether fastigial nuclei damage accounts for abnormal social behaviors seen in autism. Bilateral cannulation surgery was performed on 13 rats. An ABABAB reversal design was implemented. All animals received a microinfusion of saline during the A phases (baseline). Social interactions were tested using a social interaction chamber and an open field. Seven animals received microinfusions of bupivacaine in the B phase (treatment), which temporarily inactivated the fastigial nuclei. Six control animals received saline again, and social interaction was retested. This sequence was executed three times over six days to achieve an ABABAB design. Results indicate animals with inactivated fastigial nuclei engage in less intense social interactions and engage in more behaviors to prevent social interaction. Knowledge that the fastigial nuclei mediate social interaction can further the understanding of pathology in the autistic brain and lead to breakthrough treatments