- Author:
- WeiweiAi <wai484@aucklanduni.ac.nz>
- Date:
- 2021-11-24 17:49:12+13:00
- Desc:
- Add BG params related scripts and matrix
- Permanent Source URI:
- http://models.cellml.org/workspace/64f/rawfile/bd02dedb491faf9960ccd23496c19ccd3e339db1/doc/periodic-stimulus.rst
Periodic stimulation
--------------------------
In the `periodic stimulation experiment <../experiments/periodic-stimulus.cellml>`_, the `membrane potential model <../components/stimulated.cellml/view>`_ is configured and parameterised with an applied `periodic stimulus current <../experiments/periodic-IStim-protocol.cellml>`_.
You can change the parameters of stimulation amplitude, duration and period in the component ``stimulus_protocol_params``. By default, the current is 0.
You can also modify the parameters of temperature :math:`T`, initial depolarization :math:`V_{initial}` and boundary condition of the potential :math:`V_b`, in the component ``parameters``, ``initial_conditions`` and ``boundary_conditions`` respectively.
The simulation experiment can be obtained by loading the `corresponding SED-ML document <../sed-ml/periodic-stimulus.sedml>`__ into OpenCOR and executing the simulation.
Membrane action potential
-------------------------
Figure [#]_ shows the action potentials with different initial displacement of membrane potential (The parameter setting is in the component ``initial_conditions``).
.. [#]
.. figure:: ../sed-ml/originalFig12.png
:width: 85%
:align: center
:alt: originalFig12
Membrane potentials for initial depolarizations of -90, -15, -7 and -6 mV at 6 :math:`^{\circ} C`
Subthreshold responses
----------------------
When the displacement of membrane potential is less than the threshold for setting up a spike, characteristic subthreshold responses are seen [#]_.
.. [#]
.. figure:: ../sed-ml/originalFig21.png
:width: 85%
:align: center
:alt: originalFig21
Responses to stimuli during positive phase
------------------------------------------
The depolarization stimulation can be applied at various times during the positive phases of the membrane action potential. Figure [#]_ shows the responses of the membrane when it is depolarized by -90 mv at :math:`t=0, 4.7284, 5.7302, 7.7352 s`
.. [#]
.. figure:: ../sed-ml/originalFig20.png
:width: 85%
:align: center
:alt: originalFig20
Form of action potential at 18.5 :math:`^{\circ} C`
----------------------------------------------------
You can change the temperature T in the component ``parameters``.
Figure [#]_ shows the action potential at 18.5 :math:`^{\circ} C` with initial depolarization of -15 mV.
.. [#]
.. figure:: ../sed-ml/originalFig14.png
:width: 85%
:align: center
:alt: originalFig14
Membrane potentials for initial depolarizations of -15 mV at 18.5 :math:`^{\circ} C`
Anode break excitation
----------------------
To simulate anode break responses where current is made to flow inward through the membrane, we set the initial potential value to be 30 mV. Meanwhile, the m, n and h gate have the steady state values for :math:`V=30 mV` when :math:`t=0`. That is, we set :math:`V_b=30` in the component ``boundary_conditions``. The simulation result is shown in Figure [#]_.
.. [#]
.. figure:: ../sed-ml/originalFig22.png
:width: 85%
:align: center
:alt: originalFig22
