Stochastic Ion Channel Gating in Dendritic Neurons: Morphology Dependence and Probabilistic Synaptic Activation of Dendritic Spikes
(A–B) Rasters for first 20 trials of responses of the CA1 pyramidal neuron simulated as in Figure 8, but with stochastic axonal and deterministic dendritic ion channels (A) or stochastic denritic and deterministic axonal ion channels (B). (C) as for (A–B), but only channels mediating Ih are stochastic. Shown are rasters (left), examples of membrane potential responses of the fully deterministic model (red) and first six sweeps recorded from the stochastic model (black), and examples of membrane potential waveforms corresponding to an “extra” action potential triggered by an additional dendritic depolarization. (D) Number of “dropped” and “extra” axonal spikes (top) and dendritic spikes (bottom) during 1s of simulated time for each experimental condition tested. Because of their all or nothing nature, large dendritic depolariations are classified as spikes. ANOVA indicated a significant (p<<1e-9) effect of model configuration on “dropped” and “extra” axonal and dendritic spikes. Key post-hoc comparisons are referred to in the main text. (E) Jitter in the timing of axonal (top) and dendritic (bottom) action potentials for each experimental condition.