Fig. 5. Isoflurane decreases the P2/P1 current ratio magnitude in the presence but not in the absence of 120 μm GTPγS. The isoflurane effect on the P2/P1 current ratio magnitude in the absence (A ) and presence (B ) of 120 μm GTPγS. In the absence of GTPγS, control n = 8; isoflurane n = 11 for 0 mV and n = 12 for 10 and 20 mV. In the presence of GTPγS, control and isoflurane n = 4 at 0 mV and n = 6 for 10 and 20 mV. Significant difference between the control and isoflurane groups, +P < 0.05 unpaired t  test.