Real-time multisite observation of glutamate release in rat hippocampal slices

A multichannel glutamate sensor was fabricated that consists of enzyme modi fied electrodes and has a high sensitivity and selectivity to glutamate. We placed a rat hippocampal slice on the sensor and monitored the current at four electrodes resulting from the stimulation with muscimol, a gamma -amin obutyric acid(A) (GABA(A)) receptor agonist. We obtained different glutamat e concentration increases at the different positions, suppressed by bicucul line, a GABA(A) receptor antagonist. This demonstrated that the sensor can monitor the glutamate released via GABA(A) receptors pathways, and the diff erence in the concentrations may indicate differences in the distribution o f GABA(A) receptor as well as diverse receptor functions. This multichannel sensor may be useful for non-invasive, real-time monitoring of glutamate d istribution, which would make it a valuable tool for pharmacological analys is. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.