Microglia: proliferation and activation driven by the P2X7 receptor.

Microglial activation is associated with the pathogenesis and progression of conditions such as Alzheimer's disease (AD), Parkinsons' disease, prion disease, multiple sclerosis, and ischemic and traumatic brain injury. The molecular mechanism of microglial activation is largely unknown. The expression of the purinergic, P2X7 receptor (P2X7R), is known to be enhanced in many brain pathologies where presence of activated microglia is a concurrent feature. This review focuses on the links between P2X7R expression and microglial activation and proliferation. The P2X7R is identified as a key player in the process of microgliosis, where by driving microglial activation, it can potentially lead to a deleterious cycle of neuroinflammation and neurodegeneration.