Upregulation of an inward rectifying K+ channel can rescue slow Ca2+ oscillations in K(ATP) channel deficient pancreatic islets
Fig 8
Glycolytic oscillations drive bursting in the model KO cell.
(A) c (black) oscillates reflecting bursting electrical activity, while AMPc oscillates (blue) reflecting glycolytic oscillations. (B) Bifurcation diagram of the fast subsystem, with c∞ as bifurcation parameter. HB = Hopf bifurcation, SN = saddle-node bifurcation, SNIC = saddle-node on invariant circle bifurcation. Solid and dashed curves represent stable and unstable steady states, respectively, while bold solid and bold dashed curves represent stable and unstable limit cycles, respectively. (C) The burst trajectory projected onto the c∞-V plane. (D) Fast/slow analysis of bursting, with the burst trajectory (red) and c∞ curve superimposed onto the fast-subsystem bifurcation diagram. The c∞ curve is shown for AMPc at its minimum (dashed magenta) and maximum (dashed green) during a burst.