Albrecht, Colegrove, Hongpaisan, Pivovarova, Andrews, Friel, 2001
This model is consistently represented within the CellML but contains sets of algebraic equations that prevent the model from being solved in currently available software - 03/08.
Calcium is an important signalling ion, and changes in Ca2+ concentration ([Ca2+]) regulate diverse processes in many cellular compartments. In excitable cells, depolarisation-induced Ca2+ entry increases [Ca2+]i, leading to secondary changes in [Ca2+] within organelles such as mitochondria and ER that regulate specific Ca2+-sensitive targets within these organelles. Although mitochondria accumulate Ca2+ in response to depolarisation-evoked [Ca2+]i elevations (see The Colegrove et al Model Of Mitochondrial Ca2+ Uptake And Release, 2000), the ER has been described as either a Ca2+ source or sink. Different modes of net ER Ca2+ transport are expected to have very different effects on cytoplasmic and intraluminal Ca2+ signals and on the processes they regulate.
In their 2001 model, Meredith A. Albrecht, Stephen L. Colegrove, Jarin Hongpaisan, Natalia B. Pivovarova, S. Brian Andrews and David D. Friel have examined the relationship between changes in [Ca2+]i and [Ca2+]ER during weak depolarisation in sympathetic neurons. The total Ca2+ flux during the recovery phase following membrane depolarisation was divided into four components (see the figure below). One representing net Ca2+ extrusion across the plasma membrane (Jextru), one representing Ca2+ entry through voltage-gated Ca2+ channels (JICa), one representing ER Ca2+ uptake via a Ca2+ ATPase (JSERCA) and one representing passive ER Ca2+ release. 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:
Multiple Modes of Calcium-induced Calcium Release in Sympathetic Neurons I: Attenuation of Endoplasmic Reticulum Ca2+ Accumulation at Low [Ca2+]i during Weak Depolarisation, Meredith A. Albrecht, Stephen L. Colegrove, Jarin Hongpaisan, Natalia B. Pivovarova, S. Brian Andrews and David D. Friel, 2001, The Journal Of General Physiology , 118, 83-100. (Full text and PDF versions of the article are available for Journal Members on the JGP website.) PubMed ID: 11429446
|Schematic of the model indicating Ca2+ compartmentation in the extracellular matrix, cytosol and the ER and pathways for Ca2+ ion movement between the compartments.|