Technique provides first real-time, eagle-eye view of neural activity in mammal brains
Researchers at Duke and Stanford Universities have devised a way to watch the details of neurons at work, pretty much in real time. Every second of every day, the 100 billion neurons in your brain are capable of firing off a burst of electricity called an action potential up to 100 times per second. For neurologists trying to study how this overwhelming amount of activity across an entire brain translates into specific thoughts and behaviors, they need a faster way to watch.
A series of images from a Duke engineering experiment show voltage spreading through a fruitfly neuron over a matter of just 4 milliseconds, a hundred times faster than the blink of an eye. The technology can see impulses as fleeting as 0.2 millisecond -- 2000 times faster than a blink.
Credit: Yiyang Gong, Duke University
Existing techniques for monitoring neurons are too slow or too tightly focused to generate a holistic view. But in a new study, researchers reveal a technique for watching the brain's neurons in action with a time resolution of about 0.2 milliseconds -- a speed just fast enough to capture the action potentials in mammalian brains.
The paper appeared early online in Science on November 19, 2015: https:/
"We set out to combine a protein that can quickly sense neural voltage potentials with another protein that can amplify its signal output," said Yiyang Gong, assistant professor of biomedical engineering at Duke and first author on the paper. "The resulting increase in sensor speed matches what is needed to read out electrical spikes in the brains of live animals."
Gong did the work as a postdoctoral fellow in the laboratory of Mark Schnitzer, associate professor of biological sciences and applied physics at Stanford, and an investigator of the Howard Hughes Medical Institute. Gong and his colleagues sought out a voltage sensor fast enough to keep up with neurons. After several trials, the group landed on one found in algae, and engineered a version that is both sensitive to voltage activity and responds to the activity very quickly.
The amount of light it puts out, however, wasn't bright enough to be useful in experiments. It needed an amplifier.
To meet this engineering challenge, Gong fused the newly engineered voltage sensor to the brightest fluorescing protein available at the time. He linked the two close enough to interact optically without slowing the system down.
"When the voltage sensing component we engineered detects a voltage potential, it absorbs more light," explained Gong. "And by absorbing more of the bright fluorescent protein's light, the overall fluorescence of the system dims in response to a neuron firing."
The new sensor was delivered to the brains of mice using a virus and incorporated into fruit flies through genetic modification. In both cases, the researchers were able to express the protein in selected neurons and observe voltage activity. They were also able to read voltage movements in different sub-compartments of individual neurons, which is very difficult to do with other techniques.
"Being able to read voltage spikes directly from the brain and also see their specific timing is very helpful in determining how brain activity drives animal behavior," said Gong. "Our hope is that the community will explore those types of questions in more detail using this particular sensor. Already I've received multiple emails from groups interested in trying the technique in their own labs."
CITATION: "High-speed recording of neural spikes in awake mice and flies with a fluorescent voltage sensor," Yiyang Gong, Cheng Huang, Jin Zhong Li, Benjamin F. Grewe, Yanping Zhang, Stephan Eismann, Mark J. Schnitzer. Science, November 20, 2015. DOI: 10.1126/science.aab0810
Ken Kingery | EurekAlert!
Full of hot air and proud of it
18.04.2018 | University of Pittsburgh
Keeping the excitement under control
18.04.2018 | Max-Delbrück-Centrum für Molekulare Medizin in der Helmholtz-Gemeinschaft
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.
Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...
The Atlantic overturning – one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards – is weaker today than any time before in more than 1000 years. Sea surface temperature data analysis provides new evidence that this major ocean circulation has slowed down by roughly 15 percent since the middle of the 20th century, according to a study published in the highly renowned journal Nature by an international team of scientists. Human-made climate change is a prime suspect for these worrying observations.
“We detected a specific pattern of ocean cooling south of Greenland and unusual warming off the US coast – which is highly characteristic for a slowdown of the...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
18.04.2018 | Materials Sciences
18.04.2018 | Materials Sciences
18.04.2018 | Materials Sciences