Characterizing the voltage fluctuations driven by a cluster of ligand-gated channels

Mechanisms of stationary voltage fluctuation in the neuromuscular junction endplate and corresponding denoising paradigms

The neuromuscular junction (NMJ) has an elaborate anatomy to ensure agile and accurate signal transmission. Based on our formerly obtained expressions of the thermal and conductance induced voltage fluctuations, in this paper, the mechanisms underlying the conductance-induced voltage fluctuation are characterized from two aspects: the scaling laws with respect to either of the two system-size factors, the number of receptors or the membrane area; and the "seesaw effect" with respect to the intensive parameter, the concentration of acetylcholine. According to these mechanisms, several aspects of the NMJ anatomy are explained from a denoising perspective. Finally, the power spectra of the two types of voltage fluctuations are characterized by their specific scaling laws, based on which we explain why the endplate noise has the low-frequency property that is described by the term "seashell sound".

The voltage-depolarization performance vs the free energy cost of a single nACh receptor

The depolarization of the postsynaptic membrane potential in neuromuscular junction, which is conducted by the (stochastic) opening of nicotinic acetylcholine (nACh) receptors distributed in postsynaptic folds, is an inevitable stage in transmitting the electric signals from neural ends to muscle fibers. To perform this work, free energy must be dissipated. Being the first step in understanding the speech-accuracy-energy trade-off, we calculate the energy dissipation of a tiny membrane system that contains a single nACh receptor, i which firstly the stationary distribution of voltage is calculated based on our new method on solving the high-dimensional ODEs with variable coefficients. The ratio of the extent of depolarized-potential to the dissipated power is used to characterize the energy consuming efficiency of the system.