Abstract
Recently, the dietary intake ratio of n-3 fatty acids has dramatically decreased during several decade. Although the health influence in the change of these food habits has not been considered to be many topics until now, in a recent study, the functional relationship between n-3 fatty acids and pain or psychiatric disease or has been the focus of many studies. However, the detailed mechanisms of these disorders are fully not elucidated.
G-protein-coupled receptor 40/free fatty acid receptor 1 (GPR40/FFAR1) is activated by long-chain fatty acids such as docosahexaenoic acid (DHA) . This receptor is expressed predominantly in the central nervous system (CNS) and in β-cells of the pancreatic islets. Previously, we found that GPR40/FFAR1 is widely expressed in the CNS, and showed that the activation of GPR40/FFAR1 signaling relates to the modulation of the descending inhibition of pain. More recent our studies demonstrated that brain GPR40/FFAR1 is associated with anxiety- and depression-related behavior regulated by the increment of noradrenaline in the brain. Therefore, it is possible that brain n-3 fatty acid - GPR40/FFAR1 signaling may play a key role in the modulation of the endogenous pain control system and emotional function. In this review, we discuss the role of brain n-3 fatty acids - GPR40/FFAR1 signaling in a pain and an emotional behavior, and we review the current status and future prospects of brain GPR40/FFAR1.
