Fig. 1. Inhibition of the nicotine-induced current by halogenated compounds in PC12 cells. Cells were held at −60 mV, and 30 μm nicotine was applied for 5 s before (left column ) and after (right column ) coapplication with the halogenated agents, as indicated by a continuous line. Cells were preincubated with the halogenated compounds for 1 min before coapplication (middle column ), as indicated by a broken line. Isoflurane (top ), F6 (middle ), and F8 (bottom ) reversibly inhibited the nicotine-induced current at 0.6 MAC, and 0.55 and 0.9 predicted MAC.