[Ca2+]i Oscillations in Sympathetic Neurons
Catherine
Lloyd
Bioengineering Institute, University of Auckland
Model Status
This is the original unchecked version of the model imported from the previous
CellML model repository, 24-Jan-2006.
Model Structure
[Ca2+]i oscillations have been described in a variety of cells. They appear to be controlled by multiple mechanisms. In some excitable cells, oscillations reflect periodic depolarisation and increased Ca2+ entry across the plasma membrane. In others, oscillations are dominated by Ca2+ uptake and release by internal stores.
In his 1995 mathematical model, David D. Friel has studied caffeine-induced [Ca2+]i oscillations in sympathetic neurons. In this cell type, oscillations reflect both Ca2+ transport across the plasma membrane and uptake and release by internal stores. This model builds on previous work by examining the net fluxes of Ca2+ across the plasma membrane and between the cytosol and the intracellular store, and by presenting a quantitative model that addresses how these fluxes can together account for a periodic steady state.
The model defines four Ca2+ fluxes (see below): two are passive leaks - one representing Ca2+ entry into the cell (JL1) and one representing Ca2+ release from the intracellular store into the cytosol (JL2). The other two Ca2+ fluxes are driven against an electrochemical gradient by pumps; JP1 represents Ca2+ extrusion from the cytosol and JP2 represents Ca2+ uptake into the intracellular store from the cytosol. This mathematical model has been translated into a CellML description which can be downloaded in various formats as described in .
The complete original paper reference is cited below:
[Ca2+]i Oscillations In Sympathetic Neurons, David D. Friel, 1995,
Biophysical Journal
, 68, 1752-1766. PubMed ID: 7612818
cell schematic for the model
Schematic of the model indicating Ca2+ compartmentalization in the extracellular matrix, cytosol and the mitochondrial matrix and pathways for Ca2+ ion movement between the compartments.
$\mathrm{J\_L1}=\mathrm{k\_L1}(\mathrm{Ca\_i}-\mathrm{Ca\_o})\mathrm{K\_L1}=\frac{\mathrm{k\_L1}}{\mathrm{v\_i}}$
$\mathrm{J\_P1}=\mathrm{k\_P1}\mathrm{Ca\_i}\mathrm{K\_P1}=\frac{\mathrm{k\_P1}}{\mathrm{v\_i}}$
$\mathrm{J\_L2}=\mathrm{k\_L2}(\mathrm{Ca\_i}-\mathrm{Ca\_s})\mathrm{K\_L2}=\frac{\mathrm{K\_L2\_0}+\mathrm{K\_L2\_1}}{1.0+\left(\frac{\mathrm{Kd\_Ca}}{\mathrm{Ca\_i}}\right)^{n}}$
$\mathrm{J\_P2}=\mathrm{k\_P2}\mathrm{Ca\_i}\mathrm{K\_P2}=\frac{\mathrm{k\_P2}}{\mathrm{v\_s}}$
$\frac{d \mathrm{Ca\_i}}{d \mathrm{time}}=\mathrm{K\_L1}+\mathrm{K\_P1}+\mathrm{gamma}(\mathrm{K\_L2}+\mathrm{K\_P2})\mathrm{Ca\_i}+\mathrm{gamma}\mathrm{K\_L2}\mathrm{Ca\_s}+\mathrm{K\_L1}\mathrm{Ca\_o}\mathrm{Ca\_i\_ss}=\frac{\mathrm{Ca\_o}}{\frac{1.0+\mathrm{K\_P1}}{\mathrm{K\_L1}}}\mathrm{gamma}=\frac{\mathrm{v\_i}}{\mathrm{v\_s}}$
$\frac{d \mathrm{Ca\_s}}{d \mathrm{time}}=(\mathrm{K\_L2}+\mathrm{K\_P2})\mathrm{Ca\_i}-\mathrm{K\_L2}\mathrm{Ca\_s}\mathrm{Ca\_s\_ss}=\frac{\mathrm{Ca\_i\_ss}}{\frac{1.0+\mathrm{K\_P2}}{\mathrm{K\_L2}}}$
calcium dynamics
sympathetic
electrophysiology
neuron
Catherine
Lloyd
May
Added publication date information.
Added more metadata.
[Ca2+]i oscillations in sympathetic neurons: an experimental test of a theoretical model
68
1752
1766
David
Friel
D
2002-04-02
1995-05
7612818
c.lloyd@auckland.ac.nz
2003-04-09
A Model Of Calcium Oscillations in Sympathetic Neurons
Sympathetic Neuron
Autumn
Cuellar
A
This is the CellML description of David Friel's 1995 model of calcium
oscillations in sympathetic neurons.
2002-07-22
Biophysical Journal
keyword
The University of Auckland
The Bioengineering Institute
Catherine
Lloyd
May
The University of Auckland, Bioengineering Institute
Catherine Lloyd