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 Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>