Disrupting peripheral serotonin synthesis drives sex-specific alterations in sociability and cognition, and reshapes the gut-immune-brain axis.
Serotonin (5-HT) regulates neurodevelopment and behavior. Whereas central 5-HT is synthesized by tryptophan hydroxylase (TPH)-2, the TPH1 isoform produces 5-HT peripherally. Although these systems are anatomically segregated, TPH1 gene polymorphisms have been linked to neuropsychiatric vulnerability, suggesting that pe...