Figure 6.

Long-pass anti-coincidence duration tuning. Shown are model neuron responses to a single input stimulus that recruits standard input at 400 Hz and steep input at 250 Hz from the cochlear nucleus to illustrate model responses to a 2 ms (short) stimulus (A) and a 15 ms (long) stimulus (B). Membrane potential (voltage) traces of every neuron in the model are shown with action potentials truncated for improved subthreshold clarity. Action potentials from the cochlear nucleus Poisson spiking processes are drawn as instantaneous spikes. A, Excitation from the sustained excitation cells was suprathreshold unless it overlapped with inhibition. Therefore, the duration-tuned neuron did not fire action potentials when there was a coincidence of spikes from the adapting sustained inhibition and sustained excitation populations. B, When inhibition from the adapting sustained inhibition population decreased, excitation from the sustained excitation population broke through and produced action potentials in the duration-tuned neuron. Note how the membrane potential of the DTN at 7 ms (both stimuli) was raised by excitatory input from the sustained excitation population but did not reach threshold. Sustained excitation neurons driven by the standard cochlear nucleus Poisson spiking process; adapting sustained inhibition neurons driven by the steep cochlear nucleus Poisson spiking process (Fig. 3C). Stimulus duration is illustrated as black bars on the time axis.