Real-time detection of GABA-induced synaptic glutamate release in cultured rat cortex

Glutamate is an important neurotransmitter in synaptic transmission. There are no methods, however, for continuous measurement of glutamate concentration at high temporal and spatial resolutions. We have developed a novel electrochemical detection method for the on-line measurement of glutamate release with nanomolar resolution in real time. Using this method, GABA was found to have a modulatory action on the synaptic glutamate release in cultured rat cortical cells. This synaptic modulation largely depends on the GABA(A) receptor and could be a key not only in neural development, but also in signal transduction in the brain. Our detection method is ideal for investigating such synaptic glutamate responses because of its higher sensitivity and real-time measurement capability.