| Name | Gran_CaHVA_98 |
| Status |
| Status of element in file |
| Stable
Comment: Verified equivalence of NEURON and GENESIS mapping to orig GENESIS impl from www.tnb.ua.ac.be.
Comment: Updated to post v1.7.3 new ChannelML format
Contributor: Padraig Gleeson |
| Description |
| As described in the ChannelML file |
| A High Voltage Activated Ca2+ channel |
| Authors |
| Authors of original model: |
|
Maex, R. |
|
De Schutter, E. |
| Translators of the model to NeuroML: |
|
Padraig Gleeson
(UCL)
p.gleeson - at - ucl.ac.uk |
|
| Referenced publication | Maex, R and De Schutter, E.
Synchronization of Golgi and Granule Cell Firing in a Detailed Network Model of the
cerebellar Granule Cell Layer. J Neurophysiol, Nov 1998; 80: 2521 - 2537
Pubmed
|
| Reference in NeuronDB |
Calcium 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. |
| ca (default Eca = 0.080 V)
Reversal potential of this channel is fixed (not externally influenced):
yes |
| Default maximum conductance density |
| Note that the conductance density of the channel will be set when it is placed on the cell. |
| Gmax = 9.084216 S m-2 |
| Conductance expression |
| Expression giving the actual conductance as a function of time and voltage |
| Gca(v,t) = Gmax
* m(v,t)
2 * h(v,t)
|
| Current due to channel |
| Ionic current through the channel |
| Ica(v,t) =
Gca(v,t) * (v - Eca) |
| Q10 scaling |
| Q10 scaling affects the tau in the rate equations. It allows rate equations experimentally calculated at one temperature
to be used at a different temperature. |
|
| Q10 adjustment applied to gates: | all |
| Q10_factor: | 3 |
| Experimental temperature (at which rate constants below were determined): | 17.350264793 oC |
| Expression for tau at T using tauExp as calculated from rate equations: |
tau(T) = tauExp / 3^((T - 17.350264793)/10) |
|
| Voltage offset |
| This introduces a shift in the voltage dependence of the rate equations.
If, for example, the equation parameters being used in a model were from a different species,
this offset can be introduced to alter the firing threshold to something closer to the species
being modelled. See mappings for details. |
| 0.010 V |
|
Gate: m
The equations below determine the dynamics of gating state m
|
| Instances of gating elements | 2 |
| Closed state | m0 |
| Open state | m |
| |
| Transition: alpha from m0 to m |
| Expression | alpha(v) = A / (1 + exp((v-V1/2)/B)) (sigmoid) |
| Parameter values |
A = 1600 s-1
B = -0.01388888889 V
V1/2 = 0.005 V
|
| Substituted |
|
alpha(v) =
|
1600
|
|
1+ e (
v - (0.005))/-0.01388888889
|
|
| |
| Transition: beta from m to m0 |
| Expression | beta(v) = A*((v-V1/2)/B) / (1 - exp(-(v-V1/2)/B)) (exp_linear) |
| Parameter values |
A = 100 s-1
B = -0.005 V
V1/2 = -0.0089 V
|
| Substituted |
|
beta(v) =
|
100 * (
v - (-0.0089)) / -0.005
|
|
1- e -((
v - (-0.0089)) / -0.005)
|
|
