Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers identify enzyme that may turn fleeting experience into lasting memory

12.11.2003


The enzyme that can help turn a one-time experience into a long-term memory has been identified in mice, researchers at Wake Forest University Baptist Medical Center reported today at the annual meeting of the Society for Neuroscience in New Orleans. Ashok Hegde, Ph.D., of Wake Forest described the researchers’ work and proposed a theory for how lasting memories are formed, a process that involves the enzyme known as protein kinase C.



"One of the hallmarks of memories that last very long is a close association with emotion," Hegde said in an interview. Hegde and colleagues studied female mice, which, with only one exposure at mating, can later recognize their partner’s scent. After mating, a female mouse exposed to the scent of a strange male will not continue her pregnancy. But a female exposed to her partner’s scent even a month after mating will continue her pregnancy. This suggests that the female somehow memorized her partner’s scent during the process of mating.

"The good thing about this model," Hegde said, "is that it’s simple and robust. The memory is unambiguous, and it forms after just one event." In Hegde’s model, formation of the lasting memory in the female mouse requires that olfactory (smell) information about her partner coincide with sensory information about the mating. The information is carried by separate pathways, one involving the neurotransmitter glutamate, the other norepinephrine.


Norepinephrine, which is closely related to adrenaline, is a chemical released in the brain during emotional or exciting situations. If it does play a role in humans’ being able to vividly remember details of an experience from decades ago--where people were when they heard news of President Kennedy’s assassination, for example--the question for researches is how.

"There is a threshold for memory storage," Hegde said. "The brain has to decide what is important for long-term storage. We’re trying to understand how norepinephrine leads to strong-memory formation."

When a memory is formed, structural changes take place at synapses, the connections between nerve cells. Proteins synthesized by genes in the nerve cells cause these changes. Generally speaking, the stronger the connections among synapses, the more lasting the memory. Hegde and his colleagues--Jian Mu, M.D., Dwayne W. Godwin, Ph.D., and Chenghai Dong, M.D., Ph.D., all of the Department of Neurobiology and Anatomy--collected data from the mouse brain to suggest how norepinephrine serves as a "gatekeeper" to allow memories to form under certain circumstances.

Their research suggests that the enzyme protein kinase C plays a fundamental role in turning the female’s experience of mating into a long-term memory of her partner’s scent. Protein kinase C activates genes to express certain proteins. How protein kinase C is linked to gene expression in nerve cells is the subject of a related study by Cristian Skinner, a graduate student in the Hegde lab.

"We’ve known for a long time that you need gene expression to launch protein synthesis, which is necessary to change the synaptic connections that underlie memory," Hegde said. "This could help look at how genes work to form new connections among synapses."

In collaboration with Josyf Mychaleckyj, D.Phil., of the Wake Forest Center for Human Genomics, Hegde said, the human and mouse genomes--both of which have been completely sequenced--are systematically being searched discover genes that have a critical role in long-term memory. Also, Hegde and his assistant, Thuy Smith, are using gene chips that can screen thousands of genes at the same time to identify the "memory" genes in mice.

"The details might be different in mice and people," Hegde said, "but we think the mechanism will be the same."

Karen Richardson | EurekAlert!
Further information:
http://www.wfubmc.edu/

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 >>>