Channel Sharing in Pancreatic Beta-Cells Revisited: Enhancement of Emergent Bursting by Noise

Model Status

This model has been validated and is known to run in OpenCell to recreate the published results (figure 1). The paper by Devries and Sherman describes several different parameter sets including single cell and two cell sets, and also describes a deterministic and a stochastic model. This CellML model uses equations 1-3 and the parameters given in table 1 for the single cell deterministic model. For this particular model lambda = 0.9. Note there is a unit inconsistency in the equation for V, but our attempts to balance the units for this equation resulted in a model which no longer worked.

Model Structure

ABSTRACT: Secretion of insulin by electrically coupled populations of pancreatic beta -cells is governed by bursting electrical activity. Isolated beta -cells, however, exhibit atypical bursting or continuous spike activity. We study bursting as an emergent property of the population, focussing on interactions among the subclass of spiking cells. These are modelled by equipping the fast subsystem with a saddle-node-loop bifurcation, which makes it monostable. Such cells can only spike tonically or remain silent when isolated, but can be induced to burst with weak diffusive coupling. With stronger coupling, the cells revert to tonic spiking. We demonstrate that the addition of noise dramatically increases, via a phenomenon like stochastic resonance, the coupling range over which bursting is seen.

The original paper reference is cited below:

Channel Sharing in Pancreatic Beta-Cells Revisited: Enhancement of Emergent Bursting by Noise, Gerda De Vries and Arthur Sherman, 2000, The Journal Of Theoretical Biology , 207, 513-530. PubMed ID: 11093836

A schematic representation of the four transmembrane currents captured by the De Vries and Sherman 2000 pancreatic beta-cell model.