Fig. 9. Effect of isoflurane on NMDA-gated currents from HEK 293 cells expressing either the NR2A or NR2B subunit is shown. Current traces recorded during the application of NMDA alone and the first application of isoflurane from two HEK cells expressing NR1–1a + NR2A (A ) or NR1–1a + NR2B subunits (B ). The arrows indicate the termination of NMDA alone or NMDA + isoflurane. Note hooked tail currents on the termination of coapplication of NMDA and isoflurane, and the difference in the amplitudes of hooked tail currents from NR2A and NR2B subunit-containing receptors.