title: Stochastic modelling of cardiac cell structure.
abstract: Anatomically realistic and biophysically based computational models of the heart have provided valuable insights into cardiac function in health and disease. Nevertheless, these models typically use a "black-box" approach to describe the cellular level processes that underlie the heart beat. We are developing techniques to stochastically generate three-dimensional models of mammalian ventricular myocytes that exhibit salient characteristics of the spatial organisation of key cellular organelles in cardiac cell excitation and contraction. Such anatomically detailed models will facilitate a deeper understanding of cardiac function at multiple scales. This paper presents an important first step towards understanding and modelling the spatial distribution of two key organelles in cardiac cell contraction - myofibrils and mitochondria. The sarcolemma, myofibrils and mitochondria were segmented from transmission electron micrographs of ventricular cells from a healthy wistar rat. The centroids of the myofibrils and mitochondria were calculated, and various spatial statistical techniques for characterising the centroid distribution and inter-point interactions were investigated and implemented using the R spatstat package. Techniques for modelling the observed spatial patterns were also investigated, and preliminary results indicate that the Strauss Hard-core model best captures the interaction observed. We intend to confirm these results with larger sample of cells.
authors.affiliation: Auckland Bioengineering Institute, University of Auckland, New Zealand. ethe005@aucklanduni.ac.nz
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Theakston
authors.forename: Cameron
authors.initials: C
authors.lastname: Walker
authors.forename: Michael
authors.initials: M
authors.lastname: O'Sullivan
authors.forename: Vijay
authors.initials: V
authors.lastname: Rajagopal
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003198:Computer Simulation; D006352:Heart Ventricles / Q000648:ultrastructure*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D015233:Models, Statistical; D032383:Myocytes, Cardiac / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D013269:Stochastic Processes