Data Assimilation and Dynamical Systems Analysis of Circadian Rhythmicity and Entrainment

Wednesday, October 12th at 6-7pm in ASB 327

Please join us for a DMC Lecture Series event on Data Assimilation and Dynamical Systems Analysis of Circadian Rhythmicity and Entrainment, given by Dr. Casey Diekman of the New Jersey Institute of Technology!

Circadian rhythms are biological oscillations that align our physiology and behavior with the 24-hour environmental cycles conferred by the Earth’s rotation. In this talk, I will discuss two projects that focus on circadian clock cells in the brain and the entrainment of circadian rhythms to the light-dark cycle. Most of what we know about the electrical activity of circadian clock neurons comes from studies of nocturnal (night-active) rodents, hindering the translation of this knowledge to diurnal (day-active) humans. In the first part of the talk, we use data assimilation and patch-clamp recordings from the diurnal rodent Rhabdomys pumilio to build the first mathematical models of the electrophysiology of circadian neurons in a day-active species. We find that the electrical activity of circadian neurons is similar overall between nocturnal and diurnal rodents but that there are some interesting differences in their responses to inhibition. In the second part of the talk, we use tools from dynamical systems theory to study the reentrainment of a model of the human circadian pacemaker following perturbations that simulate jet lag. We show that the reentrainment dynamics are organized by invariant manifolds of fixed points of a 24-hour stroboscopic map and use these manifolds to explain a rapid reentrainment phenomenon that occurs under certain jet lag scenarios.

This talk was supported by a grant from the Ramapo College Foundation.

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Casey Diekman is a mathematical biologist and Associate Professor in the Department of Mathematical Sciences at the New Jersey Institute of Technology. He obtained his PhD in Bioinformatics and Industrial & Operations Engineering from the University of Michigan in 2010. Diekman was then a Postdoctoral Fellow at the Mathematical Biosciences Institute at Ohio State University until joining the NJIT faculty in 2013. Recently, he spent a year in residence at the University of Exeter as a US-UK Fulbright Scholar. Diekman’s research interests include mathematical and computational modeling of circadian (~24-hour) rhythms such as the sleep-wake cycle, data assimilation, machine learning, and dynamical systems analysis. His research has been supported by the National Science Foundation and the US Army Research Office.

Categories: Lecture Series