Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Controlling neurons with light -- but without wires or batteries

03.01.2019

University of Arizona research reveals a more sophisticated method for delivering light to control neurons in the brain -- which could ultimately mean turning off pain receptors or reducing the effects of severe neurological disorders

University of Arizona biomedical engineering professor Philipp Gutruf is first author on the paper Fully implantable, optoelectronic systems for battery-free, multimodal operation in neuroscience research, published in Nature Electronics.


Combined image analysis with MRI and CT results superimposed on a 3D rendering of the animal implanted with the programmable bilateral multi μ-ILED device.

Credit: Philipp Gutruf


Wireless and battery-free implant with advanced control over targeted neuron groups.

Credit: Philipp Gutruf

Optogenetics is a biological technique that uses light to turn specific neuron groups in the brain on or off.

For example, researchers might use optogenetic stimulation to restore movement in case of paralysis or, in the future, to turn off the areas of the brain or spine that cause pain, eliminating the need for -- and the increasing dependence on -- opioids and other painkillers.

"We're making these tools to understand how different parts of the brain work," Gutruf said. "The advantage with optogenetics is that you have cell specificity: You can target specific groups of neurons and investigate their function and relation in the context of the whole brain."

In optogenetics, researchers load specific neurons with proteins called opsins, which convert light to electrical potentials that make up the function of a neuron. When a researcher shines light on an area of the brain, it activates only the opsin-loaded neurons.

The first iterations of optogenetics involved sending light to the brain through optical fibers, which meant that test subjects were physically tethered to a control station. Researchers went on to develop a battery-free technique using wireless electronics, which meant subjects could move freely.

But these devices still came with their own limitations -- they were bulky and often attached visibly outside the skull, they didn't allow for precise control of the light's frequency or intensity, and they could only stimulate one area of the brain at a time.

Taking More Control and Less Space

"With this research, we went two to three steps further," Gutruf said. "We were able to implement digital control over intensity and frequency of the light being emitted, and the devices are very miniaturized, so they can be implanted under the scalp. We can also independently stimulate multiple places in the brain of the same subject, which also wasn't possible before."

The ability to control the light's intensity is critical because it allows researchers to control exactly how much of the brain the light is affecting -- the brighter the light, the farther it will reach. In addition, controlling the light's intensity means controlling the heat generated by the light sources, and avoiding the accidental activation of neurons that are activated by heat.

The wireless, battery-free implants are powered by external oscillating magnetic fields, and, despite their advanced capabilities, are not significantly larger or heavier than past versions.

In addition, a new antenna design has eliminated a problem faced by past versions of optogenetic devices, in which the strength of the signal being transmitted to the device varied depending on the angle of the brain: A subject would turn its head and the signal would weaken.

"This system has two antennas in one enclosure, which we switch the signal back and forth very rapidly so we can power the implant at any orientation," Gutruf said. "In the future, this technique could provide battery-free implants that provide uninterrupted stimulation without the need to remove or replace the device, resulting in less invasive procedures than current pacemaker or stimulation techniques."

Devices are implanted with a simple surgical procedure similar to surgeries in which humans are fitted with neurostimulators, or "brain pacemakers."

They cause no adverse effects to subjects, and their functionality doesn't degrade in the body over time. This could have implications for medical devices like pacemakers, which currently need to be replaced every five to 15 years.

The paper also demonstrated that animals implanted with these devices can be safely imaged with computer tomography, or CT, and magnetic resonance imaging, or MRI, which allow for advanced insights into clinically relevant parameters such as the state of bone and tissue and the placement of the device.

Emily Dieckman | EurekAlert!
Further information:
https://news.engineering.arizona.edu/news/controlling-neurons-light-without-wires-or-batteries
http://dx.doi.org/10.1038/s41928-018-0175-0

More articles from Medical Engineering:

nachricht New insight into the brain’s hidden depths: Jena scientists develop minimally-invasive endoscope
27.11.2018 | Leibniz-Institut für Photonische Technologien e. V.

nachricht New China and US studies back use of pulse oximeters for assessing blood pressure
21.11.2018 | University of British Columbia

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Programming light on a chip

Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...

Im Focus: Physicists uncover new competing state of matter in superconducting material

A team of experimentalists at the U.S. Department of Energy's Ames Laboratory and theoreticians at University of Alabama Birmingham discovered a remarkably long-lived new state of matter in an iron pnictide superconductor, which reveals a laser-induced formation of collective behaviors that compete with superconductivity.

"Superconductivity is a strange state of matter, in which the pairing of electrons makes them move faster," said Jigang Wang, Ames Laboratory physicist and...

Im Focus: Tumors backfire on chemotherapy

Some patients with breast cancer receive chemotherapy before the tumor is removed with surgery. This approach, called 'neoadjuvant' therapy, helps to reduce the size of the tumor to facilitate breast-conserving surgery, and can even eradicate the tumor, leaving few or no cancerous cells for the surgeon to remove. In those cases, the patients are very likely to remain cancer-free for life after surgery.

But not all tumors shrink under chemotherapy. If the tumor resists neoadjuvant therapy, there can be a higher risk of developing metastatic disease, meaning...

Im Focus: One of the world's fastest cameras films motion of electrons

Kiel research team examines ultrafast conversion of light energy in a solid

During the conversion of light into electricity, such as in solar cells, a large part of the input light energy is lost. This is due to the behaviour of...

Im Focus: First detection of rain over the ocean by navigation satellites

In order to analyse climate change or provide information about natural hazards, it is important to gather knowledge about the rain. Better knowledge of precipitation and its distribution could, for example, help protect against river flooding. A new approach uses, for the first time, information contained in radar signals from navigation satellites to detect rain over the sea. The technology could help to monitor atmospheric precipitation better than before.

In order to analyse climate change or provide information on natural hazards, for example, it is important for researchers to gather knowledge about rain.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

How herpesviruses shape the immune system

09.01.2019 | Health and Medicine

Stanford researchers create a wireless, battery-free, biodegradable blood flow sensor

09.01.2019 | Interdisciplinary Research

Research explains public resistance to vaccination

09.01.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>