| Name | NaChannel |
| Status |
| Status of element in file |
| Stable
Comment: Equations adapted from HH paper for modern convention of external potential being zero
Contributor: Padraig Gleeson |
| Description |
| As described in the ChannelML file |
| Simple example of Na conductance in squid giant axon. Based on channel from Hodgkin and Huxley 1952 |
| Authors |
| Translators of the model to NeuroML: |
|
Padraig Gleeson
(UCL)
p.gleeson - at - ucl.ac.uk |
|
| Referenced publication | A. L. Hodgkin and A. F. Huxley, A quantitative description of membrane current and
its application to conduction and excitation in nerve, J. Physiol., vol. 117, pp. 500-544, 1952.
Pubmed
|
| Reference in NeuronDB |
Na channels
|
| Current voltage relationship | ohmic |
| Ion involved in channel |
| The ion which is actually flowing through the channel and its default reversal potential.
Note that the reversal potential will normally depend on the internal and external concentrations of the ion at the segment on which the channel is placed. |
| na (default Ena = 50 mV)
|
| Default maximum conductance density |
| Note that the conductance density of the channel will be set when it is placed on the cell. |
| Gmax = 120 mS cm-2 |
| Conductance expression |
| Expression giving the actual conductance as a function of time and voltage |
| Gna(v,t) = Gmax
* m(v,t)
3 * h(v,t)
|
| Current due to channel |
| Ionic current through the channel |
| Ina(v,t) =
Gna(v,t) * (v - Ena) |
|
Gate: m
The equations below determine the dynamics of gating state m
|
| Instances of gating elements | 3 |
| Closed state | m0 |
| Open state | m |
| |
| Transition: alpha from m0 to m |
| Expression | alpha(v) = A*((v-V1/2)/B) / (1 - exp(-(v-V1/2)/B)) (exp_linear) |
| Parameter values |
A = 1 ms-1
B = 10 mV
V1/2 = -40 mV
|
| Substituted |
|
alpha(v) =
|
1 * (
v - (-40)) / 10
|
|
1- e -((
v - (-40)) / 10)
|
|
| |
| Transition: beta from m to m0 |
| Expression | beta(v) = A*exp((v-V1/2)/B) (exponential) |
| Parameter values |
A = 4 ms-1
B = -18 mV
V1/2 = -65 mV
|
| Substituted |
beta(v) =
4 * e
(v - (-65))/-18 |
|
Gate: h
The equations below determine the dynamics of gating state h
|
| Instances of gating elements | 1 |
| Closed state | h0 |
| Open state | h |
| |
| Transition: alpha from h0 to h |
| Expression | alpha(v) = A*exp((v-V1/2)/B) (exponential) |
| Parameter values |
A = 0.07 ms-1
B = -20 mV
V1/2 = -65 mV
|
| Substituted |
alpha(v) =
0.07 * e
(v - (-65))/-20 |
| |
| Transition: beta from h to h0 |
| Expression | beta(v) = A / (1 + exp((v-V1/2)/B)) (sigmoid) |
| Parameter values |
A = 1 ms-1
B = -10 mV
V1/2 = -35 mV
|
| Substituted |
|
beta(v) =
|
1
|
|
1+ e (
v - (-35))/-10
|
|
