Nonresolving low-grade inflammation is supposed to underly the basis of chronic disorders including cardiovascular diseases, cancer, diabetes, obesity, and psychiatric disorders such as depression and Alzheimer's diseases. There is increasing evidence suggesting that pathophysiology of psychiatric disorders is related to the inflammatory responses mediated by microglial cells. Elevation of intracellular Ca2+ is important for the activation of microglial cell functions, including proliferation, release of NO, cytokines, and BDNF. It has been shown that alteration of intracellular Ca2+ signaling underlies the pathophysiology of psychiatric disorders, including depression. BDNF induces a sustained intracellular Ca2+ elevation through the upregulation of the surface expression of TRPC3 channels in rodent microglial cells. Microglial cells are able to respond to BDNF, which may be important for the regulation of inflammatory responses and may also be involved in the pathophysiology and/or the treatment of psychiatric disorders. We also need to study the effect of proBDNF on microglial cells especially by focusing on the TRPC channels.
Keywords: BDNF; Depression; Inflammation; Microglia; TRPC3.