Intrinsic Rhythmic Fluctuation of Membrane Voltage Evoked by Membrane Noise in the Hodgkin-Huxley System

We study the influence of membrane noise on the fluctuations of membrane voltage in the Hodgkin-Huxley neuronal system for the giant axon of squids. We find that the resting potentials of membrane patches in the absence of any external stimulus, exhibit apparent rhythmic fluctuation behaviors. The intrinsic fluctuation frequencies of membrane voltage, due to channel noise, thermal noise, or both, roughly share the same frequency ranges, despite that the fluctuations arisen from the former noise are overwhelmingly larger in amplitude than that from the latter. We also show that the rhythmic fluctuations can help enhance the encoding of weak signals within the rhythmic frequencies ranges and thus contribute positively to the information processing in the nervous system.