The vagus nerve projects to the hypothalamus where oxytocin and vasopressin are produced; severing this nerve decreased gene expression and prevented rescue of oxytocin levels and social behavior in mice.

“there's this nerve called the vagus nerve which is — it's I think it means the wandering nerve vagam it's for Vagabond yeah exactly right and even it's in the gut but it actually has a direct projection to the nuclei and the hypothalamus where oxytocin and vasor pressent are made how interesting yes and so when you sever the Vagas you then in this one study it's a neuron paper — I think it's like 2020 it's a super cool paper and then what you do is you decrease the gene expression and you don't see the rescue of the oxytocin levels or the social behavior in this model”