Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Memory-boosting chemical is identified in mice

17.06.2013
UCSF cell biologists find molecule targets a key biological pathway

Memory improved in mice injected with a small, drug-like molecule discovered by UCSF San Francisco researchers studying how cells respond to biological stress.

The same biochemical pathway the molecule acts on might one day be targeted in humans to improve memory, according to the senior author of the study, Peter Walter, PhD, UCSF professor of biochemistry and biophysics and a Howard Hughes Investigator.

The discovery of the molecule and the results of the subsequent memory tests in mice were published in eLife, an online scientific open-access journal, on May 28, 2013.

In one memory test included in the study, normal mice were able to relocate a submerged platform about three times faster after receiving injections of the potent chemical than mice that received sham injections.

The mice that received the chemical also better remembered cues associated with unpleasant stimuli – the sort of fear conditioning that could help a mouse avoid being preyed upon.

Notably, the findings suggest that despite what would seem to be the importance of having the best biochemical mechanisms to maximize the power of memory, evolution does not seem to have provided them, Walter said.

"It appears that the process of evolution has not optimized memory consolidation; otherwise I don't think we could have improved upon it the way we did in our study with normal, healthy mice," Walter said.

The memory-boosting chemical was singled out from among 100,000 chemicals screened at the Small Molecule Discovery Center at UCSF for their potential to perturb a protective biochemical pathway within cells that is activated when cells are unable to keep up with the need to fold proteins into their working forms.

However, UCSF postdoctoral fellow Carmela Sidrauski, PhD, discovered that the chemical acts within the cell beyond the biochemical pathway that activates this unfolded protein response, to more broadly impact what's known as the integrated stress response. In this response, several biochemical pathways converge on a single molecular lynchpin, a protein called eIF2 alpha.

Scientists have known that in organisms ranging in complexity from yeast to humans different kinds of cellular stress — a backlog of unfolded proteins, DNA-damaging UV light, a shortage of the amino acid building blocks needed to make protein, viral infection, iron deficiency — trigger different enzymes to act downstream to switch off eIF2 alpha.

"Among other things, the inactivation of eIF2 alpha is a brake on memory consolidation," Walter said, perhaps an evolutionary consequence of a cell or organism becoming better able to adapt in other ways.

Turning off eIF2 alpha dials down production of most proteins, some of which may be needed for memory formation, Walter said. But eIF2 alpha inactivation also ramps up production of a few key proteins that help cells cope with stress.

Study co-author Nahum Sonenberg, PhD, of McGill University previously linked memory and eIF2 alpha in genetic studies of mice, and his lab group also conducted the memory tests for the current study.

The chemical identified by the UCSF researchers is called ISRIB, which stands for integrated stress response inhibitor. ISRIB counters the effects of eIF2 alpha inactivation inside cells, the researchers found.

"ISRIB shows good pharmacokinetic properties [how a drug is absorbed, distributed and eliminated], readily crosses the blood-brain barrier, and exhibits no overt toxicity in mice, which makes it very useful for studies in mice," Walter said. These properties also indicate that ISRIB might serve as a good starting point for human drug development, according to Walter.

Walter said he is looking for scientists to collaborate with in new studies of cognition and memory in mouse models of neurodegenerative diseases and aging, using ISRIB or related molecules.

In addition, chemicals such as ISRIB could play a role in fighting cancers, which take advantage of stress responses to fuel their own growth, Walter said. Walter already is exploring ways to manipulate the unfolded protein response to inhibit tumor growth, based on his earlier discoveries.

At a more basic level, Walter said, he and other scientists can now use ISRIB to learn more about the role of the unfolded protein response and the integrated stress response in disease and normal physiology.

Additional UCSF study authors are Diego Acosta-Alvear, PhD, Punitha Vedantham, PhD, Brian Hearn, PhD, Ciara Gallagher, PhD, Kenny Ang, PhD, Chris Wilson, PhD, Voytek Okreglak, PhD, Byron Hann, MD, PhD, Michelle Arkin, PhD, and Adam Renslo, PhD. Other authors are Han Li, PhD, and Avi Ashkenazi, PhD, from Genentech; and, Karim Nader, PhD, Karine Gamache, and Arkady Khoutorsky, PhD, from McGill University. The study was funded by the Howard Hughes Medical Institute.

UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.

Jeffrey Norris | EurekAlert!
Further information:
http://www.ucsf.edu

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

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 “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>