From spikers to bursters via coupling: Help from heterogeneity

It has been shown previously that identical spiking cells, incapable of bur sting by themselves, may burst under weak diffusive coupling conditions. Wi th stronger coupling, the coupled system reverts to bursting can be recover ed by introducing heterogeneity in the model parameters. For a two-cell sys tem, we explain the phenomenon with bifurcation analysis. For larger cluste rs of coupled cells, we demonstrate by numerical simulation that the phenom enon carries over. In addition, we use a perturbation analysis to deduce th e dependence of the heterogeneity parameter used in the bifurcation analysi s on the original heterogeneity parameters and the coupling strength. Impli cations of the phenomenon of emergent bursting are discussed in the context of electrical activity in pancreatic beta cells. (C) 2001 Society for Math ematical Biology.