Glutamate-evoked release of adenosine 5'-triphosphate causing an increase in intracellular calcium in hippocampal neurons.

ATP evoked an increase in intracellular Ca2+ concentration ([Ca]i) in hippocampal neurons in the presence of tetrodotoxin (TTX, 3 microM), hexamethonium (C6, 100 microM), D-2-amino-phosphonovalerate (APV, 100 microM), 6-cyano-7-nitro quinoxalline-2,3-dione (CNQX, 30 microM), bicuculline (10 microM) and cadmium (Cd2+, 300 microM). The increase was blocked by suramin (100 microM), a P2-purinoceptor blocker. These results suggest that ATP evokes an increase in [Ca]i through P2-purinoceptor. As a result of measuring [Ca]i in multiple cells simultaneously, it was suggested that glutamatergic neurones connect with purinergic neurones and glutamate (10 microM) stimulated the release of ATP causing an increase in [Ca]i in postsynaptic neurones.