Figure 1.
Inhibition of the mGluR1 current by extracellular application of phosphatase inhibitors. Voltage clamp, -75 mV. The following concentrations were used: 50 μm NBQX, 50 μm AP-5, 20 μm bicuculline, 1 μm TTX, and 0.25 μm AGA4A. A, Top traces, Currents evoked by 70μm l-glutamate in control solution, after 10 min exposure to 1 mm Na3VO4, and after 20 min wash. Middle traces, Currents evoked by 80 μm l-glutamate in control solution, after 10 min exposure to 200 μm tyrosine phosphatase inhibitor bpV(phen) and after 20 min wash. Bottom traces, Currents evoked by 70 μm l-glutamate in control solution and after 10 min exposure to 10 μm okadaic acid. No reversal on washing. B, Peak mGluR1 current plotted against l-glutamate concentration (30, 80, or 160μm; log scale). Peak current (mean ± SEM) normalized to the peak current in each cell recorded initially with 160 μm l-glutamate. Diamonds, Initial currents at each glutamate concentration. Squares, Circles, Triangles, Currents recorded after 20 min incubation in 20, 50, and 200 μm bpV(phen), respectively (4 or 5 cells at each concentration).