Figure 5.

A model of HCN including a TASK-like shunting current best approximates experimentally observed impedance profiles. Resulting impedance features when using three different models of HCN channels in the same model neuron. A: compared with the original PT model which uses the HCN and TASK-like channel models from Migliore and Migliore (41), the mechanisms developed by Kole et al. (48) and Harnett et al. (51) reduced transfer frequency along the apical trunk, but the values remain well within the experimental range. B: they led to dramatic reductions in synchronous frequency, however. HCN, hyperpolarization-activated cyclic nucleotide-gated; PT, pyramidal tract neuron; TASK, Twik-related acid-sensitive K⁺.