Graduate Student Seminar

Speaker 1: Teresa Lebair

Title

Modeling the Building Blocks of the Pancreatic Islet

Abstract

Diabetes is a pervasive, metabolic disease of elevated blood glucose levels. In order to understand this disease, it is important to study the structure and function of units in the pancreas called islets of Langerhans. We mathematically model such islets using MATLAB to simulate the electrical and hormonal activity of islet cells. Producing such a model requires us to numerically solve a large stiff system of ODEs; automatic differentiation software is used to expidite the computation of the system solution. In our preliminary study, we have adapted a Tri-Hormone Model into a multicellular computational islet to study 1) the effects of cell-type ratio dependence on secretion through paracrine interactions, 2) paracrine feedback on synchronizing cellular heterogeneity within cell-type, and 3) spatial distribution of cell-types and its effect on secretion.

Speaker 2: Zana Coulibaly

Title

Modeling Rhythms and Oscillations of Cardiac Cells via Fitzhugh-Nagumo model

Abstract

The Fitzhugh-Nagumo model is a well-known analytical reduction of the classical Hudgkin-Huxley model of action potential in excitable cells. In this talk, we will present our work on the study of the stable limit cycles of self-excitatory cardiac cells via the Fitzhugh-Nagumo model. We will describe multiple approximations of the Fitzhugh-Nagumo oscillator period and test our approximation against simulation periods. Finally, we will investigate synchrony in a 1D and 2D homogeneous and heterogeneous network of self-excitatory cells. A large portion of the work we will present was done during the Joint 2014 MBI-CAMBAM-NIMBios Summer Graduate program at the Ohio State University.