Fig. 4.
Anesthetic-induced Monod-Wyman-Changeux allosteric shifts in wild-type and M2-15′ mutant GABAA receptors. Each panel displays estimated open probability data points (the same data as in Fig. 3) for one type of receptor (identified by labels above columns) and the effects of one equieffective anesthetic solution (identified by labels to the left of rows). Lines through data points represent nonlinear least-squares fits to eq. 3 in Materials and Methods with L0 fixed and three free parameters: two that describe GABA responses and one, log(d), that quantifies anesthetic effects on gating. Lines were plotted using separate equations for GABA alone (eq. 4 in Materials and Methods; black lines) or GABA plus anesthetic (eq. 5 in Materials and Methods; colored lines). The L0 values and fitted parameters are reported in Table 2.