The brain is a reclusive organ. Neurons – the cells that make up the brain, nerves, and spinal cord – communicate with each other using electrical pulses known as action potentials, but their interactions are complicated and hard to understand.
Just getting access to the brain itself is difficult: inserting devices through the skull into the brain requires surgery. But work by Technion Professors Eitan Kimmel and Shy Shoham, and Ph.D. student Misha Plaksin, may advance our ability to unlock the brain's secrets noninvasively using sound, and perhaps create new treatments for illnesses. The findings were published today (January 21, 2014) in Physical Review X (http://link.aps.org/doi/10.1103/PhysRevX.4.011004).
Scientists have known for a while that ultrasonic waves can affect cells in many ways. For instance, physicians use ultrasound to stimulate the production of blood vessels and bone; it's also used in heat therapy. When applied to neurons, ultrasonic waves can change how the neurons generate and transmit electrical signals. "Ultrasound is known to do all kinds of things in cells," says Prof. Kimmel, "but how it works in many cases isn't clear, particularly when it comes to neural stimulation."
A new model may help clarify much of this behavior. This new way of understanding the interaction of sound waves and cells relies on the cellular membrane. This microscopic structure is the skin that surrounds a cell, keeping the organelles – like the nucleus and the DNA it contains – in, and the rest of the world out. The molecules that form the membrane are arranged in such a way that there are two layers, with a space between them. According to Kimmel's model, when the ultrasonic waves encounter a cell, the two layers of the cellular membrane begin to vibrate (much like how a person's vocal cords vibrate when air passes through the larynx). Cell membranes also act as capacitors, storing electrical charge. As the layers vibrate, the membrane's electrical charge also moves, creating an alternating current that leads to a charge accumulation. The longer the vibrations continue, the more charge builds up in the membrane. Eventually, enough charge builds up that an action potential is created.
The Technion team was able to use the model to predict experimental results that were then verified using brain stimulation experiments performed in mice by a team at Stanford University. According to Prof. Shoham, this is "the first predictive theory of ultrasound stimulation." All of these results mean that scientists might be on the verge of finally understanding how ultrasound affects nerve cells.
And this new understanding could lead to important new medical advances. For example, scientists could use ultrasonic waves to probe the brain's internal structure, a non-invasive technique that would be safer than implanting electrodes and complement the information produced by MRI scans. Physicians could also conceivably use ultrasound to treat epileptic seizures. And Shoham has begun studying the ways in which ultrasonic waves could stimulate cells in the retina, possibly creating images and letting people see without light. “There is great potential for additional applications,” says Kimmel.
The Technion team's findings also illustrate how important it is to get a theoretical understanding of things in nature. After all, says Shoham, "there's only so much you can do with effects you don't understand."
Professors Eitan Kimmel and Shy Shoham are members of the Faculty of Biomedical Engineering, and the Russell Berrie Nanotechnology Institute at the Technion-Israel Institute of Technology.
The Technion-Israel Institute of Technology is a major source of the innovation and brainpower that drives the Israeli economy, and a key to Israel’s renown as the world’s “Start-Up Nation.” Its three Nobel Prize winners exemplify academic excellence. Technion people, ideas and inventions make immeasurable contributions to the world including life-saving medicine, sustainable energy, computer science, water conservation and nanotechnology. The Joan and Irwin Jacobs Technion-Cornell Innovation Institute is a vital component of Cornell NYC Tech, and a model for graduate applied science education that is expected to transform New York City’s economy.
American Technion Society (ATS) donors provide critical support for the Technion—more than $1.9 billion since its inception in 1940. Based in New York City, the ATS and its network of chapters across the U.S. provide funds for scholarships, fellowships, faculty recruitment and chairs, research, buildings, laboratories, classrooms and dormitories, and more.
Kevin Hattori | Newswise
Imaging probe yields double insight
05.08.2015 | The Agency for Science, Technology and Research (A*STAR)
Tiny mechanical wrist gives new dexterity to needlescopic surgery
24.07.2015 | Vanderbilt University
A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...
A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...
In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.
These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...
Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.
For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...
It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.
Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...
20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
28.08.2015 | Physics and Astronomy
28.08.2015 | Health and Medicine
28.08.2015 | Life Sciences