Fig 1. NL models.
(A) Circuit of the conductance-based two-compartment HH-type "active Na" model [13,29]. The somatic compartment contains leak and KLVA currents whereas the nodal compartment has high voltage activated potassium (KHVA) and Na currents (required for spike generation) in addition to leak and KLVA. (B) Circuit of the "non-spiking" conductance-based single-compartment model with leak and KLVA currents. This model was designed for simulating subthreshold membrane responses [13,32]. (C) Membrane impedance of the somatic compartment of the active Na model. (D) Membrane impedance of the nodal compartment of the active Na model. (C-D) In the "RC only" and "RC + KLVA" conditions, g axon was fixed to zero (i.e., no axonal current) to isolate the compartment. In the "RC only" and "RC + axon" conditions, g KLVA of the compartment was fixed to zero. Membrane potential was fixed at -61 mV. (E1-3) Two-compartment active IF model: (E1) circuit diagram, (E2) average spike shape at the soma, and (E3) membrane responses to DC step current injection. Spike amplitude H = 9.7 mV. Half-amplitude spike width W = 0.3 ms. (F1-3) Single-compartment active IF model: (F1) circuit diagram, (F2) average spike shape, and (F3) membrane responses to DC step current injection. Spike amplitude H = 9.8 mV. Half-amplitude spike width W = 0.3 ms. (G1-3) Single-compartment active IF model: (G1) circuit diagram, (G2) average spike shape, and (G3) membrane responses to DC step current injection. Spike amplitude H = 9.8 mV. Half-amplitude spike width W = 0.3 ms. (E1, F1, G1) Θ denotes the IF spike generator. (E3, F3, G3) Holding potential = -60 mV.