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Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells
Published on: November 26, 2019
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A mechanism for slow rhythms in coordinated pancreatic islet activity
Nicole Bruce1, James Thornham2, I-An Wei3
1Department of Mathematics, Florida State University, Tallahassee, Florida.
Biophysical Journal
|July 27, 2024
Summary
Insulin oscillations synchronize islets of Langerhans, impacting blood glucose. A time delay in insulin feedback drives slower, ultradian rhythms, crucial for understanding type 2 diabetes.
Area of Science:
- Endocrinology
- Systems Biology
- Computational Biology
Background:
- Insulin levels oscillate rapidly, ultradianly, and circadianly, crucial for blood glucose regulation.
- Disrupted insulin rhythms are linked to type 2 diabetes.
- Islet synchronization mechanisms are not fully understood, but negative feedback is a potential driver.
Purpose of the Study:
- Investigate the origin of slow insulin oscillations and bistability with fast oscillations.
- Examine how larger islet populations synchronize under negative feedback.
- Utilize a mean-field model to understand the underlying rhythm mechanism.
Main Methods:
- Simulated larger islet populations (20-50 islets) with a negative feedback loop.
- Employed a mean-field model as a proxy for large islet populations.
- Analyzed the impact of heterogeneous intrinsic oscillation periods on synchronization.
Main Results:
- Larger islet populations primarily synchronize to slower oscillations, approximately twice the feedback delay time.
- A time delay in glucose feedback is a viable mechanism for ultradian oscillations.
- Heterogeneity in islet oscillation periods disrupts rhythmicity in small populations, akin to noise.
Conclusions:
- Negative feedback with time delay can drive synchronized ultradian insulin oscillations.
- Slower oscillations emerge in larger islet populations, distinct from faster intrinsic rhythms.
- This mechanism offers insights into glucose homeostasis and potential therapeutic targets for diabetes.
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