Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we will assume that you are happy to receive all cookies and you will not see this message again. Click 'Find out more' for information on how to change your cookie settings.

We depend on electrical waves to regulate the rhythm of our heartbeat. When those signals go awry, the result is a potentially fatal arrhythmia. Now, a team of researchers from the Department of Physiology, Anatomy and Genetics and Stony Brook University has found a way to precisely control these waves – using light. Their results are published in the journal Nature Photonics.

Both cardiac cells in the heart and neurons in the brain communicate by electrical signals, and these messages of communication travel fast from cell to cell as 'excitation waves'. Interestingly, such waves are also found in a range of other processes in nature, from chemical reactions to yeast and amoebas.

For heart patients there are currently two options to keep these waves in check: electrical devices (pacemakers or defibrillators) or drugs (eg beta blockers). However, these methods are relatively crude: they can stop or start waves but cannot provide fine control over the wave speed and direction. This is like being able to start or stop a boat but without the ability to steer it. So, the research team set out to find ways to steer the excitation waves, borrowing tools from the developing field of optogenetics, which so far has been used mainly in brain science.

Dr Gil Bub, from DPAG explained: 'When there is scar tissue in the heart or fibrosis, this can cause part of the wave to slow down. That can cause re-entrant waves which spiral back around the tissue, causing the heart to beat much too quickly, which can be fatal. If we can control these spirals, we could prevent that.

'Optogenetics uses genetic modification to alter cells so that they can be activated by light. Until now, it has mainly been used to activate individual cells or to trigger excitation waves in tissue. We wanted to use it to very precisely control the activity of millions of cells.'

A protein called channelrhodopsin was delivered to heart cells using gene therapy techniques so that they could be controlled by light. Then, using a computer-controlled light projector, the team was able to control the speed of the cardiac waves, their direction and even the orientation of spirals in real time – something that never been shown for waves in a living system before.

In the short term, the ability to provide fine control means that researchers are able to carry out experiments at a level of detail previously only available using computer models. They can now compare those models to experiments with real cells, potentially improving our understanding of how the heart works. The research can also be applied to the physics of such waves in other processes. In the long run, it might be possible to develop precise treatments for heart conditions.

Dr Emilia Entcheva, from Stony Brook University, said: 'The level of precision is reminiscent of what one can do in a computer model, except here it was done in real heart cells, in real time.

'Precise control of the direction, speed and shape of such excitation waves would mean unprecedented direct control of organ-level function, in the heart or brain, without having to focus on manipulating each cell individually. This ideal therapy has remained in the realm of science fiction until now.'

The team stresses that there are significant hurdles before this could offer new treatments – a key issue is being able to alter the heart to be light-sensitised and being able to get the light to desired locations. However, as gene therapy moves into the clinic and with miniaturization of optical devices, use of this all-optical technology may become possible. In the meantime, the research enables scientists to look into the physics behind many biological processes, including those in our own brains and hearts.

 

The paper, Optical control of excitation waves in cardiac tissue, is published in the journal Nature Photonics on 19 October 2015: doi: 10.1038/NPHOTON.2015.196


Source: Oxford University website

Similar stories

Reducing fat in the diabetic heart could improve recovery from heart attack

New research from the Heather Group has shown that in type 2 diabetes an overload of lipids reduces the heart’s ability to generate energy during a heart attack, decreasing chances of recovery.

The brain’s one-sided teaching signals

A new study by the Lak group reveals a novel facet of dopamine signalling during visual decision making.

Fellowship awarded to Huriye Atilgan to enhance our understanding of value-based decision-making

Congratulations are in order for Postdoctoral Research Scientist Dr Huriye Atilgan who has been awarded a prestigious Sir Henry Wellcome Postdoctoral Fellowship funded by the Wellcome Trust.

The future of stroke treatment

A team of international collaborators including DPAG's Dr Mootaz Salman has been researching a promising new therapeutic for the treatment of strokes and other brain injuries.

New review reveals proof of concept for an anti-obesity immunotherapy

The Domingos lab has published a new opinion piece in Science investigating the implications of a Memorial Sloan Kettering Cancer Center study that lays the foundations for a potential new anti-obesity treatment in the form of targeting adipose tissue-resident macrophages.