Fig. 5.

Computational simulations of electrocyte APs in a model electrocyte with (A–D) and without K_Na channels (E–G). A: membrane potential (V_m) of the posterior (red), central (black), and anterior (blue) compartments of a model cell with K_Na during a train of 10 APs elicited at 500 Hz by simulated synaptic conductances. B: time course of the Na⁺ current (I_Na), K_Na current (I_KNa), and synaptic current (I_Syn) during the AP train shown in A. C: time course of internal Na⁺ concentrations ([Na⁺]_i) in the posterior (red), central (black), and anterior (blue) compartments during the AP train shown in A. The different initial Na⁺ concentrations reflect the equilibrium of resting Na⁺ leak, pumping, and diffusion rates as shown in D. D: posterior V_m and time course of [Na⁺]_i in the posterior (red), central (black), and anterior (blue) compartments during the same simulation shown in A, but on an expanded timescale that shows the initial changes in Na⁺ concentrations as the Na⁺ leak, pumping, and diffusion processes reach equilibrium. E: V_m of the posterior (red), central (black), and anterior (blue) compartments of a model cell without K_Na during a train of 10 APs elicited at 500 Hz by simulated synaptic conductances. F: time course of I_Na, I_KNa, and I_Syn during the AP train shown in E. G: time course of [Na⁺]_i in the posterior (red), central (black), and anterior (blue) compartments during the AP train shown in E. The different initial Na⁺ concentrations reflect the equilibrium of resting Na⁺ leak, pumping, and diffusion rates as shown in D.