Wave-Block Due to a Threshold Gradient Underlies Limited Coordination in Pancreatic Islets

Two models for coupled pancreatic β cells are used to investigate excited wave propagation in spatially inhomogeneous islets of Langerhans. The application concerns spatial variation of glucose concentration across the islet. A comprehensive model of coupled cells shows that wave blocking occurs as the conductance of adenosine triphosphate regulated potassium channels increases, corresponding to spatially decreasing glucose concentration. A simplified model based on a perturbed version of Fisher’s equation has been investigated using perturbation theory. We show that the perturbed Fisher’s equation likewise can exhibit wave blocking.