A recent study suggested that neuroinflammation plays a major role in the pathogenesis of a number of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Although the precise mechanism is obscure, dysregulation of the signaling transduction pathway in microglia may enhance inflammation, leading to synaptic dysfunction and ultimately to neuronal cell death. The expression and function of the P2X7 receptor (P2X7R), an ATP-gated ion channel abundantly expressed in microglia in the brain, is significantly up-regulated in the postmortem brain of Alzheimer's disease patients and various neurodegenerative disease animal models. This supports the role of the P2X7R pathway in the progression of neurodegeneration. Blocking P2X7R using brilliant blue G, a P2X7R antagonist that can cross the blood-brain barrier, has been shown to result in the amelioration of neuropathology in various animal models. Taken together, these results raise the possibility that the P2X7R signaling pathway could be a therapeutic target for treating various neurodegenerative diseases.