Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Heartbeat Is Complex, Synchronized Event, Find Weizmann Institute and Penn Scientists


Two hearts, said Keats, can beat as one, but a study led by Weizmann Institute scientists in collaboration with researchers from the University of Pennsylvania shows that sometimes a single heart muscle cell can beat as more than two dozen.

The findings, reported recently in Nature Communications, provide an extremely detailed glimpse into the mechanisms behind normal and irregular heart muscle cell contractions. The study may help define the limitations of existing therapies for abnormal heartbeat and, in the future, suggest ways of designing new ones.

Weizmann Institute of Science

A chicken heart-muscle cell under a fluorescent microscope; the filaments consist of repeated subunits (bright dotted lines). The schematic representation shows three neighboring filaments; the black lines are the boundaries of their subunits, such that the lower filament is aligned with the middle one, while the upper one is not.

Each heart muscle cell consists of numerous parallel filaments comprising repeated subunits. When the heart beats, each individual filament contracts to produce muscle cell contractions.

Optimally, all the filaments should contract in a synchronized manner, thus ensuring the greatest amplitude of contraction for each muscle cell and ultimately, the strongest and most effective beating of the entire heart. However, a new theoretical model proposed and analyzed by Prof. Samuel Safran and postdoctoral fellow Dr. Kinjal Dasbiswas of the Weizmann Institute’s Department of Materials and Interfaces suggests that the filaments contract together only when their subunits, and subunit boundaries, are aligned with one another.

Since such alignment usually only happens among a limited number of neighboring filaments, these contract together as a bundle -- however, each such bundle contracts out of phase with others. Therefore, a heart cell does not necessarily beat as a single uniform entity; rather, the number of different beating entities in the cell depends on the bundle number, which may reach more than two dozen.

The theory, which uses the methods of statistical physics, further predicted that the alignment of the filaments in the heart muscle cell depends on the cell’s physical environment, and more specifically on the elasticity of the supporting structure (called the extracellular matrix). The alignment is best when this structure is not too soft and not too rigid. The prediction took into consideration various forces operating on the microscale, particularly mechanical forces that are exerted on each filament subunit by neighboring filaments via the extracellular matrix.

By assuming that only structurally aligned filaments beat together, the Weizmann theorists were able to quantitatively explain experimental findings by their collaborators from the University of Pennsylvania (aka Penn), Prof. Dennis Discher and Dr. Stephanie Majkut. In the experiments, the Penn scientists had placed embryonic heart cells from chicks on support surfaces of varying stiffness, and found that two strikingly different properties – the structural alignment of the filaments and the beating strength of the cell – depended on the rigidity of the supporting surface.

By providing a theoretical basis for these experiments, the Weizmann model may help explain how filaments become aligned in heart muscle cells during embryonic development, and how their arrangement correlates with the muscle function in the adult heart.

This correlation suggests that the current means of treating irregular heartbeat may be limited to a certain extent by the structural order of heart muscle filaments – however, the new understanding may one day help design improved treatments for heart disease. For example, in the future, if new heart cells are grown to replace diseased ones, their growth environment may be manipulated so that their structure is well ordered and, to paraphrase Keats, all their filaments beat as one.

Prof. Samuel Safran’s research is supported by the Gerhardt M.J. Schmidt Minerva Center on Supramolecular Architectures, which he heads; the US-Israel Binational Science Foundation; the Israel Science Foundation; Antonio and Noga Villalon, Winnetka, IL; the Clore Center for Biological Physics; the Kimmelman Center for Structural Biology; and the Kimmel Stem Cell Research Institute. Prof. Safran is the incumbent of the Fern and Manfred Steinfeld Professorial Chair.

Dr. Kinjal Dasbiswas’s research is supported by a fellowship from the Council of Higher Education.

Contact Information
Jennifer Manning
Director, Science Content
Phone: 212-895-7952

Jennifer Manning | newswise

More articles from Health and Medicine:

nachricht Inflammation Triggers Unsustainable Immune Response to Chronic Viral Infection
24.10.2016 | Universität Basel

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>