"... To study the mechanisms underlying AP initiation in unmyelinated hippocampal mossy fibers of adult mice, we recorded sodium currents in axonal and somatic membrane patches. We demonstrate that sodium channel density in the proximal axon is ~5 times higher than in the soma. Furthermore, sodium channel activation and inactivation are ~2 times faster. Modeling revealed that the fast activation localized the initiation site to the proximal axon even upon strong synaptic stimulation, while fast inactivation contributed to energy-efficient membrane charging during APs. ..."
Model Type: Neuron or other electrically excitable cell
Cell Type(s): Dentate gyrus granule GLU cell
Model Concept(s): Action Potential Initiation
Simulation Environment: NEURON
Schmidt-Hieber C, Bischofberger J. (2010). Fast sodium channel gating supports localized and efficient axonal action potential initiation. The Journal of neuroscience : the official journal of the Society for Neuroscience. 30 [PubMed]