The What and Where of Adding Channel Noise to the Hodgkin-Huxley Equations
Figure 1
Analysis of responses of channel noise models for a fixed voltage trajectory.
(A) Voltage trace obtained from the Markov chain model with no current input, 6,000 channels and 1,800
channels. Dynamics are characterized by a prolonged subthreshold period followed by a spontaneous, channel noise-induced spike at
. (B) Means of fraction of open
and
channels for the voltage trace shown in (A), as computed from Equations 10 and 11. (C) Variance in the fraction of open
channels. (D) Variance in the fraction of open
channels. Left insets in (C and D) show magnified views of the period preceding the spike. Right inset in (C) shows magnified view during the spike. For (C and D), exact variances (black) were computed from Equation 12 and Equation 13 and all other variances were estimated from 5,000 repeated simulations of the channel noise models.