Figure 5.

Glial glutamate release contributes to ambient glutamate concentration. A, Tonic and slow transient currents are unmasked by bath application of TBOA (100 μm). B, Effect of TBOA on the frequency of slow transient currents (ANOVA test; p < 0.001). The voltage dependency of slow transient currents during the application of TBOA was obtained with 1 mm Ca²⁺ and 1 mm Mg²⁺ in the extracellular solution (inset). The bars from left to right correspond to the mean amplitude of transient currents measured at -70, -30, 0, and +30 mV (n = 3; Student's t test, p < 0.05). C, The cumulative distributions of the rise time (left) and amplitude (right) of the slow transient currents are shifted to the right during TBOA application (Kolmogorov-Smirnov test; p < 0.001). Ctrl, Control.