Figure 6. .

The nonlinear dependence of the steady-state open-state dynamics of the ChR2 channel on stimulus frequency and light intensity. The method for obtaining the open-state statistics is visualized in Figure 2C. (A) The response minimum of the open-state probability increases with increasing frequency. Light intensity causes a slight increase at higher frequencies, but generally only exhibits a minor effect on the response minimum. (B) The response maximum decreases as the frequency increases. It scales monotonically with light intensity until it saturates. (C) The response pulse duration decreases with frequency, and increases with light intensity until saturation.