The xpp files below were used in R. Bertram and A. Sherman. 2004. Filtering of calcium transients by the endoplasmic reticulum in pancreatic beta-cells, Biophys. J., 87:3775-3785.[PubMed]

Cartoons of Two-Compartment (Left) and Three-Compartment (Right) Models:

The model reproduces the experiments in Arredouani et al, Am. J. Physiol. 282:E982-E991, 2002 [PubMed]

XPP files by figure

• Two-Compartment Model (no CICR) (Figures 2 - 6; see ode file for details of how to produce each figure) [two-cmpt.ode]
  • Key Finding: Tg increases peak Ca, lowers nadir in agreement with experiment. Effects of increasing glucose and external Ca are also reproduced, and the effect of increasing ER leak is predicted.
• Compound Ca Oscillations (Figures 7, 8; see ode file for details of how to produce each figure) [compound.ode]
  • Key Finding: Ca builds with each pulse in the compound burst provided the kineteics of cytosolic Ca are neither too slow nor too fast.
• Two-Compartment Model (with CICR) (Figures 9, 10; see ode file for details of how to produce each figure) [cicr.ode]
  • Key Finding: If CICR is strong enough to produce net emptying of the ER during the active phase of a burst, then dumping the stores with Tg reduces Ca amplitude, in contradiction to the experiments.
  • Note: kserca3=0.05, kserca2b=0.002 ms^{-1}; incorrect in Table 1 of paper.
• Three-Compartment (Subspace) Model (Figure 11) [three-cmpt.ode]
  • Adapted from subspace model (model 2) in M. Zhang, P. Goforth, A. Sherman, R. Bertram, and L. S. Satin. 2003, Biophys. J. 84:2852-2870. [PubMed] [XPP Files]