Microglial signal transduction as a target of alcohol action in the brain

Although alcohol is believed to exert deleterious effects on the nervous system in general, its specific effect on the brain's immune system remains poorly understood. In particular, the effects of alcohol consumption on the immune and inflammatory responses in the central nervous system (CNS) have not been extensively investigated. Here, reviewed is the recent progress on how ethanol influences the signal transduction pathways of the inflammatory activation of brain microglia, which are thought to function as the resident immune defense system of the brain. Microglia are the CNS representatives of macrophages, which have the ability to clean up cellular debris. Microglia participate in neuroinflammation in response to various intrinsic or extrinsic stimuli. It has been recently suggested that microglial signal transduction is one of the main targets of ethanol action in the brain: ethanol exposure selectively modulates the intracellular signal transductions of microglia, rather than globally inhibiting signaling pathways in a nonspecific manner. Deregulation by ethanol of the inflammatory activation signaling of microglia may contribute to the derangement of CNS immune and inflammatory responses.