Several studies have revealed that during brain injury and under pathological conditions, neurons,223 astrocytes,189 and microglia224 release high concentration of ATP that acts as a neuromodulator of the P2Y receptors.134,225 P2Y receptor activation then induces fast synaptic transmission through postsynaptic P2X receptors in the brain.135 Therefore, P2Y receptors affect the release of number of neurotransmitters225 through actions on calcium influx.226
