Impact of Fast Sodium Channel Inactivation on Spike Threshold Dynamics and Synaptic Integration
Figure 9
Effective postsynaptic potential with synaptic filtering.
A, Normalized biexponential PSPs obtained with non-instantaneous synaptic currents (i.e., postsynaptic currents are exponentially decaying with time constant τs between 1 ms and 20 ms). B, As for exponential PSPs (Figure 8), effective PSPs (ePSPs) are narrower and change sign (only the positive part is shown). The time to peak is also shorter. Threshold adaptation parameters were and dθ/dV = 1. C, The peak time increases with the synaptic filtering time constant τs, but less rapidly for ePSPs than for PSPs. D, ePSP peak time vs. PSP peak time. Threshold adaptation makes peak times shorter and compressed.