Effects of modifying speed of intracellular currents upon depth of PRC delay in Type II neurons.

(A–C) Effects of modifying the speed of the potassium current in the Type II Morris-Lecar neuron, with increasing values of implying faster dynamics (). (A) PRCs of the neuron for three sample values of , with . As the speed of the potassium dynamics increases, the PRC delay depths grow progressively larger. (B) Absolute value of the delay depth of the PRCs as a function of , for four different values of , which correspond to those in Fig. 1C. (C) Neuronal firing frequency as a function of , for the same values of as in panel B. Note how linear growth of results in sub-linear growth of the frequency, indicating that the delay depth is largely determined by the speed of the potassium current relative to the spiking frequency of the neuron. (D–F) Effects of modifying the speed of the slow potassium gating variable in the Type II cortical pyramidal cell model. (D) PRCs of the neuron for three sample values of , with . (E) Absolute value of the delay depth of the PRCs as a function of , for four different values of , which correspond to those in Fig. 1F. (F) Neuronal firing frequency as a function of , for the same values of as in panel E. (G–I) Effects of modifying the speed of the sodium inactivation gating variable in the cortical pyramidal cell model. (G) PRCs of the neuron for three sample values of , with . (H) Absolute value of the delay depth of the PRCs as a function of , for four different values of , which correspond to those in Fig. 1F. (I) Neuronal firing frequency as a function of , for the same values of as in panel H.