Fewer neutrophils extravasate in acute peritonitis, lung inflammation, and skin wounds in the absence of non-neuronal serotonin. (A) Gr-1 and CD11b-positive neutrophils in abdominal lavages of WT and Tph1^−/− mice 4 hours after intraperitoneal injection of thioglycollate (n = 10) or zymosan (n = 4). (B) Neutrophil recovery in bronchoalveolar lavage 24 hours after inhalation with LPS (n = 6). (C) Tissue MPO concentration and hematoxylin-eosin staining in 24-hour-old skin wounds (n = 10). (D) Time to closure of skin wounds (n = 10).