There is an increasing recognition of the role of neurotrophins in the mature gastrointestinal tract both at the physiological and pathological levels. However, their expression and role in smooth muscle in the GIT system is under investigated. The aim of this study is to elucidate the expression of the four neurotrophins in smooth muscle tissue of the rat colon and to test the effect of dextran sodium sulphate (DSS) - induced colitis on the expression pattern of these factors. Using specific ELISA kits for each neurotrophin revealed that the four neurotrophins are differentially expressed in the longitudinal and circular muscle layers of the rat colon and that DSS-induced colitis alters this expression pattern. These results indicate that smooth muscle tissue contributes to the pool of neurotrophins in the GIT and might play a role in the pathogenesis of colitis. Understanding the interactions of neurotrophins produced from smooth muscle and colitis could provide new avenues to tackle the dysfunction associated with inflammatory bowel diseases such as colitis.