Researchers at the Institute of Molecular Pathology (IMP) and the Max F. Perutz Laboratories (MFPL) in Vienna, Austria, collaborated with scientists at the MIT to create an imaging system that reveals neural activity throughout the entire nervous system of living animals. This technique, the first that can generate 3-D movies of entire brains at the millisecond timescale, could help to discover how neuronal networks process sensory information and generate behavior. The new approach is described in an online publication by the journal Nature Methods on May 18, 2014.
The team used the new system to simultaneously image the activity of every neuron in the worm Caenorhabditis elegans, as well as the entire brain of a zebrafish larva, offering a more complete picture of nervous system activity than has been previously possible.
This image shows the head region and the majority of the brain of a zebrafish larvae, as recorded and reconstructed using the light-field microscope. IMP
“The new method is an indispensible tool to understand how the brain represents and processes sensory information and how this leads to cognitive functions and behaviour,” says physicist Alipasha Vaziri, a joint group leader at the IMP and MFPL and head of the research platform „Quantum Phenomena & Nanoscale Biological Systems“ (QuNaBioS) of the University of Vienna, who led the project. “Because of the enormous density of the interconnection of nerve cells in the brain, relevant information is often encoded in states of this densely interconnected network of neurons rather than in the activity of individual neurons.”
Vaziri’s team developed the brain-mapping method together with researchers in the lab of Edward Boyden, an associate professor of biological engineering and brain and cognitive sciences at the Massachusetts Institute of Technology.
High-speed functional 3-D imaging
Neurons encode information - sensory data, motor plans, emotional states, and thoughts - using electrical impulses called action potentials, which provoke calcium ions to stream into each cell as it fires. By engineering model organisms that carry fluorescent proteins which glow when they bind calcium, scientists can visualize this electrical firing of neurons in live animals. However, until now there has been no way to image this neural activity over a large volume, in three dimensions, and at high speed.
Scanning the brain with a laser beam can produce 3-D images of neural activity, but it takes a long time to capture an image because each point must be scanned individually. The research-team wanted to achieve similar 3-D functional images but accelerate the process so they could see neuronal firing, which takes only milliseconds, as it occurs.
The new method is based on a technology known as light-field imaging, which creates 3-D images by capturing angular information of incoming rays of light. In the new paper, the researchers in Vienna and Cambridge built a light-field microscope which was optimized to have single neuron resolution and applied it, for the first time, to imaging of neural activity.
With this kind of microscope, the light emitted by the sample is sent through an array of lenses that refracts the light in different directions. Each point of the sample generates about 400 different points of light, which can then be recombined using a computer algorithm to recreate 3-D structures.
“Compared to existing methods, our new technology allows us to capture neuronal activity in volumes up to a thousand times larger at ten times higher speed”, says Robert Prevedel, a postdoc in the Vaziri Lab and first author of the paper. ”We have eliminated the need to scan multiple layers, thus the temporal resolution is only limited by the camera sensor and the properties of the molecules themselves.” Prevedel built the microscope at the IMP in Vienna. Young-Gyu Yoon, a graduate student at MIT and co-first author, devised the computational strategies that reconstruct the 3-D images.
Neurons in action
The researchers used the technique to image neural activity in the worm C. elegans, the only organism for which the entire neural wiring diagram is known. This one-millimeter worm has 302 neurons, each of which the researchers imaged as the worm performed natural behaviors, such as crawling.
To demonstrate the power of the new technology in higher organisms, they also studied larvae of zebrafish. Their nervous system consists of over 100 000 neurons that fire at a much faster rate, rather like humans. In the tiny larvae, the scientists were able to induce neuronal response to odor stimuli in around 500 neurons and track the nerve signals simultaneously in about 5000 activated neurons.
The findings could be ultimately useful in developing new types of algorithms that simulate functions of the brain and predict behaviour. Such models are in high demand in the area of machine learning and object recognition and classification.
The work in Vienna was funded by the Vienna Science and Technology Fund (WWTF), the Research Platform Quantum Phenomena and Nanoscale Biological Systems (QuNaBioS), the Human Frontiers Science Program, the European Commission, the VIPS Program of the Austrian Federal Ministry of Science and Research,the City of Vienna, and the Vienna Scientific Cluster (VSC).The IMP is funded by Boehringer Ingelheim.
Prevedel R, Yoon Y-G, Hoffmann M, Pak N, Wetzstein G, Kato S, Schrödel T, Raskar R, Zimmer M, Boyden ES und Vaziri A. Simultaneous whole-animal 3D-imaging of neuronal activity using light-field microscopy. Nature Methods Advance Online Publication, 18 March, 2014. DOI 10.1038/nmeth.2964.
Images and videos to illustrate this press release are available from the IMP Website at http://www.imp.ac.at/pressefoto-zebrafish
About the IMP
The Research Institute of Molecular Pathology (IMP) in Vienna is a basic biomedical research institute largely sponsored by Boehringer Ingelheim. With over 200 scientists from 37 nations, the IMP is committed to scientific discovery of fundamental molecular and cellular mechanisms underlying complex biological phenomena. Research areas include cell and molecular biology, neurobiology, disease mechanisms and computational biology.
About the MFPL
The Max F. Perutz Laboratories (MFPL) are a center established by the
University of Vienna and the Medical University of Vienna to provide an
environment for excellent, internationally recognized research and
education in the field of Molecular Biology. Currently, the MFPL host around 60
independent research groups, involving more than 500 people from 40 nations.
Ass. Prof. Dr. Alipasha Vaziri, Gruppenleiter
Research Institute of Molecular Pathology (IMP)
Max F. Perutz Laboratories (MFPL) und Research Platform Quantum Phenomena & Nanoscale Biological Systems (QuNaBioS), University of Vienna
Dr. Heidemarie Hurtl, Communications
IMP Research Institute of Molecular Pathology
T +43-1-79730 3625
Dr. Heidemarie Hurtl | idw - Informationsdienst Wissenschaft
Rochester scientists discover gene controlling genetic recombination rates
23.04.2018 | University of Rochester
One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
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...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
23.04.2018 | Physics and Astronomy
23.04.2018 | Physics and Astronomy
23.04.2018 | Trade Fair News