REVIEW ARTICLESThe complex role of serotonin and 5-HT receptors in chronic painBardin, Laurent Author Information Division of Neurobiology 2, Centre de Recherche Pierre Fabre, Castres, France Correspondence to Dr Laurent Bardin, Ph D, Division of Neurobiology 2, Centre de Recherche Pierre Fabre, 17, Avenue Jean Moulin, 81106 Castres, France E-mail: [email protected] Received February 22, 2011 Accepted May 18, 2011 Behavioural Pharmacology 22(5 and 6):p 390-404, September 2011. | DOI: 10.1097/FBP.0b013e328349aae4 Buy Metrics Abstract Serotonin [5-hydroxytryptamine (5-HT)] in the central nervous system and in the periphery has long been considered to have an important role in the control of pain, for example, through descending inhibition. In recent years, considerable research efforts have focused on the role played by 5-HT on acute or chronic pain states as well as on the identification of the respective 5-HT receptors involved. However, preclinical studies have reported conflicting observations, and numerous important questions remain unanswered. The purpose of this study is to provide an analysis of the recent developments in understanding the role of 5-HT both within the periphery and at the level of the spinal dorsal horn. We discuss the inhibitory or facilitatory influences exerted by 5-HT, through the descending 5-HT pathway, on spinal processing of nociceptive information in pathological pain states. Evidence with regard to the possible implication of the 5-HT1A, 5-HT2A, 5-HT3, and 5-HT7 receptors in pain modulation is also reviewed. Recent studies (both behavioral and clinical, relevant to these targets) have indeed demonstrated that 5-HT1A and 5-HT7 receptor agonists or 5-HT2A and 5-HT3 receptor antagonists may be promising therapeutic agents for the treatment of pain states. © 2011 Lippincott Williams & Wilkins, Inc.