APL Colloquium

October 2, 2015

Colloquium Topic: Biased excitable networks: how cells direct motion in response to gradients

Chemotaxis, the directed motion of cells in response to chemical gradients, requires the coordinated action of three different and separable processes: motility, gradient sensing and polarization.
Much effort has been expended understanding each of these processes, and numerous mathematical models have been proposed that explain each one.  In this talk I will present a comprehensive model that explains all three aspects of chemotaxis.  The central element is the presence of a biased excitable system.  This model takes into account reports that the actin cytoskeleton and other signaling elements in motile cells have many of the hallmarks of an excitable medium, including the presence of propagating waves. This excitable behavior can account for the spontaneous migration of cells. We suggest that the chemoattractant-mediated signaling can bias excitability, thus providing a means by which cell motility can be directed. We also provide a mechanism for cell polarity that can be incorporated into the existing framework.

Colloquium Speaker: Pablo Iglesias

Pablo A. Iglesias was born in Caracas, Venezuela.  He received the B.A.Sc. degree in Engineering Science from the University of Toronto in 1987, and the Ph.D. degree in Control Engineering from Cambridge University in 1991. Since then he has been on the faculty of the Johns Hopkins University, where he is currently the Edward J. Schaefer Professor of Electrical Engineering. He also holds appointments in the Departments of Biomedical Engineering, and Applied Mathematics & Statistics as well as the Department of Cell Biology in the Johns Hopkins School of Medicine. He has had visiting appointments at Lund University (Automatic Control), The Weizmann Institute of Science (Mathematics), the California Institute of Technology (Control and Dynamical Systems), and the Max-Planck Institute for the Physics of Complex Systems in Dresden, Germany.

Dr. Iglesias’s research focuses on the use of control and information theory to study biological signal transduction pathways.