Fig. 7.

Izhikevich neurons possess similar intrinsic and rebound spiking properties as stellate cells. (a and b) In response to a chirp function stimulus (a1, b1) a low frequency Izhikevich neuron displays a lower depolarized resonance frequency (a2, 4.425 Hz) and a lower resonance frequency near its resting membrane potential (a3, 4.852 Hz) compared to a high frequency Izhikevich neuron (b2, 5.249 Hz; b3, 6.897 Hz). Differential frequency preferences were achieved by tuning the a parameter in Eq. (6) (low frequency cell, a = 0.007; high frequency cell, a = 0.015). (c) In response to hyperpolarizing square current steps, Izhikevich neurons display a prominent sag potential and upon release of the current step, fire rebound spikes (# denotes truncated spikes, data shown from low frequency cell in a). (d) When the low (d1) and high (d2) frequency Izhikevich neurons receive hyperpolarizing synaptic input pulses superimposed on a sinusoid, the cells spike to a subset of phases of hyperpolarizing input pulses. (e and f) Rose plots show the phases of hyperpolarizing input pulses inducing spikes for the low (e1) and high (e2) frequency Izhikevich neuron, as well as each cell's respective phase range of output spiking (f1, f2). (g and h) Summary bar graphs show how increasing the baseline oscillation frequency (g) and the magnitude of hyperpolarizing inputs (h) affect the input MRA (g1, h1) and output MRA (g2, h2) of the low frequency cell.