Neuronal population model of globular bushy cells covering unit-to-unit variability
Fig 1
Empirical response patterns of GBC and schematic drawings of the model structure and PSTH output.
A-B: PSTHs of cat GBCs: a PLN-type (A) and an OnL-type (B). Adapted from [24]. C-D: Low-frequency phase histograms of a cat auditory nerve (C) and GBC (D). Adapted from [25]. CF: characteristic frequency; VS: vector strength. E: Operation of the adaptive coincidence counting model (see Materials and Methods for the equations). The model neuron receives ME excitatory synaptic inputs (red) simulated by the AN model (ME = 3 in this example). Each presynaptic input spike (small vertical red bar) induces a postsynaptic response of a length WE and amplitude AE in the model neuron (black rectangular bump on left). The adaptive threshold θ(t) (green), parameterized by a time scale TA and strength SA, develops according to the summed input count v(t) (black). When the input count reaches or exceeds the threshold (arrowhead), an output spike is generated (blue). After each spike output, the model is in the refractory period of a duration TR (gray), in which no further spikes can be generated. Insufficient synchrony of input spikes (three inputs on right) leads to a failure of output spike generation due to the adaptive threshold. F: Components of a primary-like-with-notch (PLN) peristimulus time histogram (PSTH) used for judging the plausibility of each instance of the modeled bushy cell. Depending on the parameters used, a second notch may or may not exist while the other components almost always appear.