Cardiac myocytes dynamic contractile behavior differs depending on heart segment

Title : Cardiac myocytes dynamic contractile behavior differs depending on heart segment

Abstract:

Cardiac myocytes originating from different parts of the heart exhibit varying morphology and ultrastructure. However, the difference in their dynamic behavior is unclear. We examined the contraction of cardiac myocytes originating from the apex, ventricle, and atrium, and found that their dynamic behavior, such as amplitude and frequency of contraction, differs depending on the heart segment of origin. Using video microscopy and highprecision image correlation, we found that: (1) apex myocytes exhibited the highest contraction rate (_17 beats/min); (2) ventricular myocytes exhibited the highest contraction amplitude (_5.2 micron); and (3) as myocyte contraction synchronized, their frequency did not change significantly, but the amplitude of contraction increased in apex and ventricular myocytes. In addition, as myocyte cultures mature they formed contractile filaments, further emphasizing the difference in myocyte dynamics is persistent. These results suggest thatthe dynamic behavior (in addition to static properties) of myocytes is dependent on their segment of origin.

Biography:

Dr. De Souza is a physicist interested in cell physiology, cellular mechanics and in particular how mechanotransduction impacts the differentiation of stem cell into myocytes. He received his Ph.D. degree from Max Planck Institute for Intelligent Systems, Germany. Thereafter, he joined the Leibniz Institute for New Materials and the University of Illinois at Urbana Champaign, USA as a postdoctoral fellow. He researched how adhesion and mobility affects the contraction of primary myocytes and the differentiation of stem cell into cardiac cells. He developed devices to measure forces and stimulate single myocytes. Dr. De Souza currently collaborates with researchers at the University of British Columbia, Canada.