Lateralized vagal oxytocin signaling separately controls feeding and socioemotional functions via hypothalamic oxytocin signaling
Oxytocin neurons in the paraventricular hypothalamus (PVHOxt) regulate feeding, anxiety, and social behaviors. Activation of Oxt receptor (Oxtr) -expressing vagal sensory neurons engages these PVHOxt neurons and improves hyperphagic obesity; however, their roles in anxiety and sociability remain unclear. Here, we activated vagal Oxtr-expressing neurons in male mice using a single intraperitoneal (IP) Oxt injection or chemogenetics. IP Oxt reduced anxiety-like behavior, enhanced social interaction, and suppressed feeding while activating both vagal sensory neurons and PVHOxt neurons. These effects were abolished by chemogenetic inhibition of PVHOxt neurons or central Oxtr blockade. Subdiaphragmatic vagotomy revealed lateralized functions: right-side vagotomy eliminated anxiolytic and prosocial effects, whereas left-side vagotomy blocked feeding suppression. Consistently, chemogenetic activation of left-sided neurons suppressed feeding, while right-sided activation reduced anxiety and increased sociability. These findings identify Oxtr-expressing vagal sensory neurons as a major peripheral pathway in which left- and right-sided inputs differentially control feeding and socioemotional behaviors.