Glutamates released from synaptic vesicles by sequential spikes into synaptic cleft are constancy.

<p>uGTCs were recorded at unitary synapses from a pyramidal neuron to an astrocytes. <b>A</b>) uGTC1∼5 are induced by five sequential spikes. <b>B</b>) shows the distributions of uGTC1∼5 at this synapse. <b>C</b>) illustrates uGTC1∼5 averaged from other synapses (n = 7). <b>D</b>) uGTC1∼5 are blocked by TBOA, an antagonist of glutamate transporter.