In the CNS, adenosine 5′-triphosphate (ATP), an energy source for neurons and glial cells, also acts as an extracellular purinergic signaling molecule that controls communication between brain cells.8 The steady state concentration of cytosolic ATP is high, ranging between 5 and 10 mM, and very low (nM) in the extracellular space.9 Under pathological conditions and CNS insults such as trauma, ischemic stroke, epileptogenic seizures, cellular stress, neuroinflammation, and neurodegenerative disorders, high concentration of ATP is released to the extracellular region as a danger signal creating a cascade of events that eventually damages the neurons.10,11
