Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Revolutionary nanotechnology illuminates brain cells at work

31.05.2005


Until now it has been impossible to accurately measure the levels of important chemicals in living brain cells in real time and at the level of a single cell. Scientists at the Carnegie Institution’s Department of Plant Biology and Stanford University are the first to overcome this obstacle by successfully applying genetic nanotechnology using molecular sensors to view changes in brain chemical levels. The sensors alter their 3-dimensional form upon binding with the chemical, which is then visible via a process known as fluorescence resonance energy transfer, or FRET. In a new study, the nanosensors were introduced into nerve cells to measure the release of the neurotransmitter glutamate--the major brain chemical that increases nerve-cell activity in mammalian brains. It is involved in everything from learning and memory to mood and perception. Too much glutamate is believed to contribute to conditions such as Alzheimer’s and Parkinson’s disease. The research is published in the May 30-June 3 on-line early edition of the Proceedings of the National Academy of Sciences.



"The fluorescent imaging technique allows us to see living cells do their jobs live and in color," explained Sakiko Okumoto, lead author of the study at Carnegie. "Understanding when and how glutamate is produced, secreted, reabsorbed, and metabolized in individual brain cells, in real time, will help researchers better understand disease processes and construct new drugs."

"FRET is like two musical tuning forks, which have the same tone," Okumoto continued. "If you excite one, it gives a characteristic tone. If you bring the second fork close to the first one, it will also start to give you a tone even though they do not touch. This is resonance energy transfer."


FRET is used to track the form of proteins that specifically bind metabolites such as sugars and amino acids. A protein of interest is genetically fused with two differently colored tags made from variants of the jellyfish Green Fluorescent Protein (GFP). The colored tags are placed at each end of the molecule making a "biosensor." When the substance of interest binds to the sensor, the sensor backbone becomes reoriented, and the reorientation can be detected. Since light is a vibration, the same response occurs with two fluorescent dyes that have overlapping, but slightly different colors–in this case cyan and yellow versions of GFP. The cyan is excited and, if the distance between the colored proteins changes, more or less energy is transferred to the yellow protein. In this study, the cyan and yellow proteins behave as if they move away from one another when the sensor recognizes glutamate. Thus, there is more cyan and less yellow light than in the absence of glutamate. The sensors are encoded by genes and genetic ZIP codes can be used to target the sensors to any location in the cell and to its surface.

"We used a protein called ybeJ from the common bacterium E. coli. We first predicted the structure of this protein, and then placed the two fluorophores at specific positions on the binding protein," commented co-author Loren Looger. "After fusion to the fluorescent proteins, we placed the sensor on the surface of rat hippocampal cells. The hippocampus is the part of the brain that is involved with emotional reactions, and it helps store learned information in memory. When neurons are activated, they secrete glutamate, and we could see this activity under the microscope by watching the color change. We stimulated the neurons and watched them secrete glutamate in response. We also saw the removal of the glutamate as the neurons returned to normal ready to fire again."

"This is a tremendously exciting technology," remarked Wolf Frommer, leader of the FRET team at Carnegie. "I’m anxious to see what we can learn about the vast complexities of the brain over the coming years, such as the role of glial cells in the process of glutamate removal from the synaptic cleft. It’s fascinating to see a tool that we are using in plant biology open new areas in neuroscience."

Wolf Frommer | EurekAlert!
Further information:
http://www.carnegieinstitution.org

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>