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Role of the Ventral Pallidum in the Regulation of Social Play Behavior in Juvenile Rats |
Abstract
Social play behavior is a rewarding behavior and displayed by juveniles of many mammalian species. Engagement in social play behavior is important for the development of social competence throughout life. Children diagnosed with neurodevelopmental disorders such as autism spectrum disorder (ASD) show social play deficits, which may contribute to their life-long social deficits.
Therefore, it is essential to understand how the brain modulates the expression of typical and impaired social play behavior. In the present study, we aimed to determine the role of the ventral pallidum (VP) in modulating social play behavior in male and female juvenile rats. The VP is a brain region that regulates adult social behaviors such as maternal behavior and pair-bonding, but its role in regulating juvenile social behaviors, such as social play, is unknown. We first determined whether activation of the VP is required for the expression of social play by temporarily inactivating the VP via local infusion of the GABAA receptor agonist muscimol. We found that pharmacological inactivation of the VP decreased social play behaviors in male and female rats. Next, we determined whether exposure to social play altered neuronal activation of the VP using fos as measure of cellular activity. We observed that social play exposure increased the number of fos-positive cells in the VP in males while no changes in fos-positive cells were observed in females. Together, these findings provide first evidence that activation and sex-specific recruitment of VP cells is essential for the expression of social play behavior in juvenile rats.