Transforming XML file: NeuroMLFiles/Examples/ChannelML/KChannel_oldFormat.xml
using XSL file:
NeuroMLFiles/Schemata/v1.8.1/Level3/NeuroML_Level3_v1.8.1_HTML.xsl
View original file before transform
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Converting the file: KChannel_oldFormat.xml
| General notes |
| Notes present in ChannelML file |
| ChannelML file containing a single Channel description |
| Unit system of ChannelML file |
| This can be either SI Units or Physiological Units (milliseconds, centimeters, millivolts, etc.) |
| Physiological Units |
Ions involved in this channel:
| Ion: k |
| One of the ions involved in this channel. Note that the reversal potential used here is a typical value, it should be determined for each cell type based on ionic concentrations |
| Charge: 1
Default reversal potential: -77.0 mV
|
Channel: KChannel
| Name | KChannel |
| Status |
| Status of element in file |
| Deprecated. File may still work but a new form of some elements is preferred!
Comment: This form of ChannelML (with ohmic and hh_gate elements) should no longer be used. See KChannel_HH.xml instead.
Contributor: Padraig Gleeson |
| Description |
| As described in the ChannelML file |
| Simple example of K conductance in squid giant axon. Based on channel from Hodgkin and Huxley 1952 |
| 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 |
K channels
|
| Current voltage relationship |
| Note: only ohmic and integrate_and_fire current voltage relationships are supported in current specification |
| 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 depend on the internal and external concentrations of the ion at the segment on which the channel is placed. |
| k (default Ek = -77.0 mV) |
| Default maximum conductance density |
| Note that the conductance density of the channel will be set when it is placed on the cell. |
| Gmax = 36 mS cm-2 |
| Conductance expression |
| Expression giving the actual conductance as a function of time and voltage |
| Gk(v,t) = Gmax
* n(v,t)
4
|
| Current due to channel |
| Ionic current through the channel |
| Ik(v,t) =
Gk(v,t) * (v - Ek) |
|
Gate: n
The equations below determine the dynamics of gating state n
|
| Gate power | 4 |
| Gating model formalism | Hodgkin Huxley single state transition |
| Expression controlling gate: |
|
dn(v,t)
|
= alpha(v) * (1-n)
- beta(v) * n
|
or
|
dn(v,t)
|
=
|
inf(v) - n
|
|
dt
|
dt
|
tau(v)
|
|
| alpha |
| Form of rate equation for alpha | Parameterised HH |
| Expression | alpha(v) = A*(k*(v-d)) / (1 - exp(-(k*(v-d)))) (linoid) |
| Parameter values |
A = 0.1 ms-1
k = 0.1 mV-1
d = -55 mV
|
| Substituted |
|
alpha(v) =
|
0.1 *
0.1 * (
v - (-55))
|
|
1- e -(0.1 * (
v - (-55)))
|
|
| beta |
| Form of rate equation for beta | Parameterised HH |
| Expression | beta(v) = A*exp(k*(v-d)) (exponential) |
| Parameter values |
A = 0.125 ms-1
k = -0.0125 mV-1
d = -65 mV
|
| Substituted |
beta(v) =
0.125 * e
-0.0125 *(
v - (-65)) |
| tau |
| Expression for tau |
|
tau(v) =
|
1
|
|
alpha(v) + beta(v)
|
|
| inf |
| Expression for inf |
|
inf(v) =
|
alpha(v)
|
|
alpha(v) + beta(v)
|
|
|
Implementation Preferences
Information is provided to help produce the best implementation of the channel
mechanism. Due to some parameters in the channel mechanism the default values used in the
simulator mappings may not be sufficient, e.g. if the rate equations change rapidly,
but the default table size isn't large enough.
|
| Settings for rate equation tables |
| Recommended settings if a table of values is used to speed up calculation
of the rate equation values. |
| Number of table divisions: 400
Maximum voltage for tables: 100 mV
Minimum voltage for tables: -100 mV
|
|
Time to transform file: 0.418 secs
