Periodic spiking by a pair of ionic channels

• Published in: Physica A 2018-09, Vol.505, p.345-354
• Main Authors: Ramírez-Piscina, L., Sancho, J.M.
• Format: Article
• Language: English
• Subjects: Channel gating; Física; Física de fluids; Física de plasmes; Langevin equations; Nonlinear oscillations; Oscil·lacions de plasma; Periodic firing; Àrees temàtiques de la UPC
• ISSN: 0378-4371; 1873-2119
• DOI: 10.1016/j.physa.2018.03.075

Neuronal cells present periodic trains of localized voltage spikes involving a large amount of different ionic channels. A relevant question is whether this is a cooperative effect or it could also be an intrinsic property of individual channels. Here we use a Langevin formulation for the stochastic dynamics of a pair of Na and K ionic channels. These two channels are simple gated pore models where a minimum set of degrees of freedom follow standard statistical physics. The whole system is totally autonomous without any external energy input, except for the chemical energy of the different ionic concentrations across the membrane. As a result it is shown that a unique pair of different ionic channels can sustain membrane potential periodic spikes. The spikes are due to the interaction between the membrane potential, the ionic flows and the dynamics of the internal parts (gates) of each channel structures. The spike involves a series of dynamical steps being the more relevant one the leak of Na ions. Missing spike events are caused by the altered functioning of specific model parts. The time dependent spike structure is comparable with experimental data. •It is shown that a simple pair of two actives pores can sustain periodic spikes.•Spike temporal structure is comparable to real neural pulses.•Spike periodicity and its statistical properties are well characterized.•Control parameters are the out cell ionic concentrations.•The sources of spiking misfunctioning are well established in terms of the system parameters.