Subthreshold Voltage Noise due to Channel Fluctuations in Active Neuronal Membranes Voltage-gated ion channels in neuronal membranes uctuate randomly between dierent conformational states due to thermal agitation. We compute the magnitudes, amplitude distributions, and power spectral densities of the voltage noise in isopotential membrane patches predicted by these kinetic schemes. For both schemes, noise magnitudes increase rapidly with depolarization from rest.
Noise is larger for smaller patch areas but is smaller for increased model temperatures.