FIGURE 2.

Effect of gating threshold. Two different ΔFs, smaller and greater than the default value of 1.5 pN, were compared. A and B compare the channel activations along time at different ΔFs. The smaller ΔF resulted in greater peak current and smaller residual current after the fast adaptation. (C) When ΔF = 4.5 the active F-X curve bifurcates from the passive curve at a greater displacement. However, as the displacement increases the two active curves become closer. (D) As ΔF increases, the activation curve shifts to the right. At ΔF = 0.5 pN, the hair cell was very sensitive at its resting state and as small as 3 pN of stimulus activated more than 30% of channels. The solid lines are the curve fits of data points measured at ΔF = 0.5, 1.5, and 4.5 pN, respectively. The data points at ΔF = 1.5 were not shown.