2016
10th Lorenz Kramer Memorial Lecture
Synchronization of Spatial Patterns - A Matter of Life or Death
Prof. Alain Pumir
(ENS de Lyon, France)
October 11, 2016
Abstract:
Synchronous activity of all cells in a tissue is a key to the proper functioning of several important organs, in particular those performing a mechanical task. Specific examples include the heart, whose function is to pump blood throughout the whole body, or the uterus, whose contractions lead to the expulsion of the newborn. One of the motivations for understanding and controlling the rhythm comes from the consequences associated with improper synchronization (arrhythmias) in such tissues.
In the two examples above, the mechanical activity (contraction) is triggered by electric waves of depolarization. I will discuss the mechanism leading to synchronization in these two organs. Whereas in the heart, the activity is centrally coordinated by specialized (pacemaker) cells, spontaneously oscillating cells have not been found in the uterus. The physiological changes observed in the organ during pregnancy suggest a prominent role of the coupling between the cells in the tissue. I will discuss the situation using model studies.
n the heart, the control of arrhythmias is mostly done by using electric fields. Defibrillation shocks remain the only reliable way to treat patient with a severe arrhythmia, such as ventricular tachycardia. I will discuss the physical aspects of the interaction between an externally applied electric field and cardiac tissue, and the importance of devising treatments involving electric fields with a weaker intensity. In particular, I will present the method of Low Energy Antifibrillation Pacing (LEAP), and its potential advantages for the treatment of arrhythmias.
Alain Pumir