Figure 8.
Firing rate (top), κ (middle), and CV (bottom) for stationary (left) and periodically modulated inputs (right). Left, The firing rate, κ, and CV were calculated from the ISIs recorded by whole-cell patch-clamp technique for synaptic inputs with constant parameters: Vr = −40 or −44 mV and ge0 = 0.012, 0.018, 0.024, or 0.030 μS. Right, The same quantities were calculated for inputs with varying parameters: Vr = 44 mV and ge0 was controlled as ge0(t) = 0.021 + 0.009 sin(2 πt/T), where T (100, 200, 400, 600, 800, 1200, or 1600 ms) denotes the period of the sinusoidal modulation. In each trial, the fluctuating current Isyn was injected for 10 seconds (0 < t < 10 s). The gray lines show the ranges of statistics (firing rate, κ, and CV) for stationary inputs with Vr = −44 mV. The irregularity for the modulated inputs stays in the range for any period, whereas CV does not. Only κ is robust against the rate modulation.