Central Nervous System: (Immunological) Ivory Tower or Not?

The view of the nervous system being the victim of destructive inflammation during autoimmunity, degeneration, or injury has been rapidly changing. Recent studies are supporting the idea that the immune system provides support for the nervous system at various levels. Though cell patrolling through the nervous system parenchyma is limited compared with other tissues, immune cell presence within the central nervous system (CNS; microglia), as well as around it (in the meningeal spaces and choroid plexus) has been shown to be important for brain tissue maintenance and function. This review primarily explores recent findings concerning neuroimmune interactions and their mechanisms under homeostatic conditions.