Fig. 6.
Differential effects of distinct mGluR subtypes on postsynaptic membrane properties. A, MembraneI–V relationship before and after application of DHPG (30 μm, bath). The I–V curve was obtained by plotting current changes (averaged steady-state current values at 5–10 msec before offset of voltage step) against membrane potentials. Currents were generated by a series of command voltage pulses. Pulse step size was 5 mV; pulse width was 100 msec; and pulse frequency was 2 Hz. Note that the membrane input resistance increased in the DHPG condition as indicated by the reduced slope of the I–Vplot. B, I–V relationship, obtained by subtracting the I–V relationship during DHPG treatment from that in the control condition, for the DHPG-induced inward current (IDHPG). These experiments were performed in the presence of TTX (1 μm, bath).C, D, Membrane I–Vrelationships before and after applications of 4C3HPG (50 μm, bath; C) and l-AP4 (5 μm, bath; D).