A reduced model for the synchronization of oscillations in pancreatic islets

Nicole Bruce

Florida State University

"A reduced model for the synchronization of oscillations in pancreatic islets"

Insulin is secreted in pulses by beta-cells located within pancreatic islets. This pulsatility is reflected in blood insulin measurements, indicating that the activity of hundreds of thousands of islets is synchronized. One possible mechanism for this synchronization is a negative feedback loop between the pancreas and liver hepatocytes, in which the action of hepatocytes to lower glucose levels in response to insulin serves as a global coordinating signal to pancreatic islets. With a time delay in the glucose response, small populations of in vitro and computer simulated model islets display bistability, capable of producing both fast and slow coordinated oscillations. We investigate the dynamic mechanism for this bistability through simulations with large islet populations, long time delays, and a reduced model that captures the dynamics of the full closed-loop system with only two variables.
Additional authors: Richard Bertram

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