Role of network connectivity and fluctuations in the nucleation of calcium waves in cardiac cells

by Hernandez Gonzalo Hernandez

Institution: California State University – Northridge
Year: 2016
Keywords: network; Dissertations, Academic  – CSUN  – Physics and Astronomy.
Posted: 02/05/2017
Record ID: 2135123
Full text PDF: http://hdl.handle.net/10211.3/172171


Spontaneous calcium release (SCR) occurs when ion channel fluctuations lead to the nucleation of calcium waves in cardiac cells. This phenomenon is important since it has been implicated as a cause of various cardiac arrhythmias. However, to date, it is not understood what determines the timing and location of spontaneous calcium waves within cells. Here, we analyze a simplified model of SCR in which Ca release is modelled as a stochastic processes on a two dimensional network of randomly distributed sites. Using this model we identify the essential parameters describing the system and compute the phase diagram. In particular, we identify a critical line which separates pinned and propagating fronts, and show that above this line wave nucleation is governed by fluctuations and the spatial connectivity of Ca release units. Using a mean field analysis we show that the sites of wave nucleation are predicted by localized eigenvectors of a matrix representing the network connectivity of release sites. This result provides insight on the interplay between connectivity and fluctuations in the genesis of SCR in cardiac myocytes. Advisors/Committee Members: Shiferaw, Yohannes (advisor), Cadavid, Ana C (committee member).