In neocortical layer-5 pyramidal neurons, the action potential (AP) is generated in the axon initial segment (AIS) when the membrane potential (Vm) reaches the threshold for activation of NaV1.6 and Nav1.2 voltage- gated Na+ channels, that differ in spatial distribution and biophysical properties. Here, we used ultrafast Na+, Vm and Ca2+ imaging in combination with pharmacological blocks of different channels to demonstrate the exclusive role of each of them in shaping the generating AP. We mimicked the experimental results with this NEURON model where the role of the different ion channels tested reproduced the experimental evidence. Nav1.2 and BK channels interaction shapes the action potential in the axon initial segment DOI: 10.1113/JP283801
Model Type: Neuron or other electrically excitable cell; Axon
Region(s) or Organism(s): Neocortex
Cell Type(s): Neocortex layer 5 pyramidal cell
Currents: I Potassium; I Sodium; I Calcium
Model Concept(s): Action Potentials; Action Potential Initiation; Axonal Action Potentials
Simulation Environment: NEURON
Implementer(s): Filipis, Luiza [luizafilipu at gmail.com]
References:
Filipis L et al. (2023). Nav1.2 and BK channels interaction shapes the action potential in the axon initial segment The Journal of physiology. [PubMed]