Abstract
Microglia are intrinsic immune cells which release factors, including proinflammatory cytokines, nitric oxide (NO) and neurotrophins, following activation after disturbance in the brain. There is increasing evidence suggesting that pathophysiology of neuropsychiatric disorders such as schizophrenia and depression is related to inflammatory responses mediated by microglia. Microglial activation might not be the primary cause of neuropsychiatric disorders but could be closely related to the pathophysiology of acute stage of neuropsychiatric disorders. We and other researchers have recently shown the inhibitory effects of some antidepressants as well as antipsychotics on the release of inflammatory cytokines and NO from activated microglia, possibly through the modulation of intracellular Ca2+ signaling. Brain- derived neurotrophic factor (BDNF) is a neurotrophin well known for its roles in the activation of microglia as well as in pathophysiology and/or treatment of neuropsychiatric disorders. BDNF also modulates microglial intracellular Ca2+ signaling and precursor BDNF (proBDNF) could play important roles in microglial functions and could also be involved in the pathophysiology of neuropsychiatric disorders.
