Figure 9.

Concentration‐dependent modulation of persistent current by MLA. A lower level of persistent current was induced with the protocol illustrated in Figure 4A (30 μM NS6740 application following a 30 μM GAT107 application). MLA was then applied at progressively higher concentrations as indicated. Following the applications of MLA at 1, 10 and 100 nM, an additional application of 1 nM MLA was made in order to determine the reproducibility of the low concentration response. Following the sequence of four MLA applications, 100 μM mecamylamine (Mec) was applied in order to illustrate the channel blocking effect on the persistent current. Data in the traces are averaged from 7 cells, each normalized to the initial responses to 60 μM ACh obtained from the same cells (average ACh responses were 1.8 ± 0.3 μA). Vertical scale bars are based on averaged ACh controls. The upper trace shows the entire experiment. The lower trace shows just responses to the first three MLA applications at a scale threefold increased both vertically and horizontally. The dashed line represents the original baseline.