Figure 3. Concentration dependence of the volatile anesthetic effects on miniature inhibitory postsynaptic current (mIPSC) amplitude. Data are normalized to control values and plotted versus (A) the aqueous anesthetic concentration or versus (B) the fraction of the MACAq(that is, the concentration values were normalized to estimated MACAqvalues for enflurane [0.577 mM], isoflurane [0.297 mM, and halothane [0.247 mM]). Numbers in parentheses in panel A refer to the numbers of cells for each data point, and they are the same for panel B. Squares = enflurane, circles = isoflurane, and triangles = halothane. Dashed lines are Hill Equation fitsto the data.