Hodgkin and Huxley established that sodium currents in the squid giant axons activate after a delay, which is explained by the model of a channel with three identical independent gates that all have to open before the channel can pass current (the HH model). It is assumed that this model can adequately describe the sodium current activation time course in all mammalian central neurons, although there is no experimental evidence to support such a conjecture. We performed high temporal resolution studies of sodium currents gating in three types of central neurons. ... These results can be explained by a model with two closed states and one open state. ... This model captures all major properties of the sodium current activation. In addition, the proposed model reproduces the observed action potential shape more accurately than the traditional HH model. See paper for more and details.
Model Type: Channel/Receptor
Cell Type(s): Dentate gyrus granule GLU cell; Hippocampus CA1 pyramidal GLU cell; Neocortex L5/6 pyramidal GLU cell; Neocortex L2/3 pyramidal GLU cell
Currents: I Na,t
Model Concept(s): Action Potential Initiation; Ion Channel Kinetics; Action Potentials
Simulation Environment: NEURON
Implementer(s): Baranauskas, Gytis [baranauskas at elet.polimi.it]
References:
Baranauskas G, Martina M. (2006). Sodium currents activate without a Hodgkin-and-Huxley-type delay in central mammalian neurons. The Journal of neuroscience : the official journal of the Society for Neuroscience. 26 [PubMed]