The proportion of nNOS-IR neurons to the total number of neurons 24 hours post induction of colitis was greater in TNBS-only (31.9±1.8%) and UCM-treated (31.7±1.2%) guinea-pigs compared to sham (20±0.5%), MSC (21±1%), and CM-treated (22±1%) animals (P<0.001 for all; Fig 11B). This evidence concerns the gene NOS1 and colitis.