Mast cells in the brain - Old cells, new target.

Mast cells (MCs) are mainly known for their involvement on allergic reactions through degranulation and release of vasoactive, inflammatory and nociceptive mediators. Upon encountering an allergen, MCs are first responders, true sensors of the environment, actually they respond to a wide range of "danger" signals both immunological and non-immunological in rapid and selective manner. They secrete both preformed and newly synthesized mediators acting as effectors in relationship between nervous, vascular and immune systems. For this peculiarity, MCs are "master regulators" and key players of the immune system as well as important source of essential and beneficial mediators with crucial roles in the regulation of various physiological processes. MCs are unique cells with multiple capabilities. It has well known that MCs are critical for the pathogenesis of inflammatory disease. MCs exert their effect through alteration of vascular permeability and recruitment of inflammatory cells. While a functional involvement of peripheral MCs in inflammatory conditions is well established, the role of Central Nervous System MCs is not well understood yet. Increasing evidence indicate that in the brain, the inflammation is strongly involved in the pathogenesis of neurodegenerative and neuropsychiatric diseases. In this review, we discuss some aspects of the current knowledge of MCs role in the brain and their potential role as therapeutic emerging target for neural diseases.