Fig. 4.

Exogenous glutamate induced whole-cell currents before and after ischemia. A, Application of exogenous glutamate induced an inward current at a holding potential of −60 mV in the presence of 50 μmd-APV. The glutamate responses were antagonized by SYM 2206, a specific AMPAR antagonist (A1). The amplitude of glutamate-induced currents was increased accordingly with increasing concentrations of glutamate before (A2) and after (A3) ischemia. B, Dose–response curve of glutamate responses before and after ischemia. The EC₅₀values and Hill coefficients of the dose–response curve after ischemia were approximately the same as those in control neurons.C, Comparison of current densities of glutamate-induced currents in LA neurons before and after ischemia. The current density was slightly decreased at 4 hr after ischemia, but no statistic significance was detected.