Featured Research

from universities, journals, and other organizations

Major clue in long-term memory-making

Date:
March 21, 2011
Source:
Duke University Medical Center
Summary:
You may remember the color of your loved one's eyes for years. But how? Scientists believe that long-term potentiation (LTP) -- the long-lasting increase of signals across a connection between brain cells -- underlies our ability to remember over time and to learn, but how that happens is a central question in neuroscience.

Image shows the formation of dendritic spines during long-term potentiation in a single synapse. Signaling activity is color coded (red = high activity of Cdc42, blue = low activity). Activity is high only in the growing spine, and this shows Cdc42 helps to strengthen a synapse for long-term memory storage.
Credit: Ryohei Yasuda, Duke University Medical Center

You may remember the color of your loved one's eyes for years. But how? Scientists believe that long-term potentiation (LTP) -- the long-lasting increase of signals across a connection between brain cells -- underlies our ability to remember over time and to learn, but how that happens is a central question in neuroscience.

Researchers at Duke University Medical Center have found a cascade of signaling molecules that allows a usually very brief signal to last for tens of minutes, providing the brain framework for stronger connections (synapses) that can summon a memory for a period of months or even years.

Their findings about how the synapses change the strength of connections could have a bearing on Alzheimer's disease, autism and mental retardation, said Ryohei Yasuda, Ph.D., assistant professor of neurobiology and senior author.

"We found that a biochemical process that lasts a long time is what causes memory storage," said Yasuda, who is a Howard Hughes Medical Institute Early Career Scientist.

This work was published in the March 20 issue of Nature.

The researchers were investigating the signaling molecules that regulate the actin cytoskeleton, which serves as the structural framework of synapses.

"The signaling molecules could help to rearrange the framework, and give more volume and strength to the synapses," Yasuda said. "We reasoned that a long-lasting memory could possibly come from changes in the building block assemblies."

The Duke researchers knew that long-term potentiation, a long-lasting set of electrical impulses in nerve cells, is triggered by a transient increase of calcium (Ca2+) ions in a synapse. They devised experiments to learn exactly how the short Ca2+ signal, which lasts only for ~0.1s, is translated into long-lasting (more than an hour) change in synaptic transmission.

The team used a 2-photon microscopy technique to visualize molecular signaling within single synapses undergoing LTP, a method developed in the Yasuda lab. This microscopy method allowed the team to monitor molecular activity in single synapses while measuring the synapses for increase in their volume and strength of the connections.

They found that signaling molecules Rho and Cdc42, regulators of the actin cytoskeleton, are activated by CaMKII, and relay a CaMKII signal into signals lasting many minutes. These long-lasting signals are important for maintaining long-lasting plasticity of synapses, the ability of the brain to change during learning or memorization.

Many mental diseases such as mental retardation and Alzheimer's disease are associated with abnormal Rho and Cdc42 signals, Yasuda said. "Thus, our finding will provide many insights into these diseases."

Other authors include lead author Hideji Murakoshi and Hong Wang of the Duke Department of Neurobiology.

This study was funded by Howard Hughes Medical Institute, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, National Institute of Drug Abuse, the Alzheimer's Association and the Japan Society for the Promotion of Science.


Story Source:

The above story is based on materials provided by Duke University Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hideji Murakoshi, Hong Wang, Ryohei Yasuda. Local, persistent activation of Rho GTPases during plasticity of single dendritic spines. Nature, 2011; DOI: 10.1038/nature09823

Cite This Page:

Duke University Medical Center. "Major clue in long-term memory-making." ScienceDaily. ScienceDaily, 21 March 2011. <www.sciencedaily.com/releases/2011/03/110320164231.htm>.
Duke University Medical Center. (2011, March 21). Major clue in long-term memory-making. ScienceDaily. Retrieved April 15, 2014 from www.sciencedaily.com/releases/2011/03/110320164231.htm
Duke University Medical Center. "Major clue in long-term memory-making." ScienceDaily. www.sciencedaily.com/releases/2011/03/110320164231.htm (accessed April 15, 2014).

Share This



More Health & Medicine News

Tuesday, April 15, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
Cognitive Function: Is It All Downhill From Age 24?

Cognitive Function: Is It All Downhill From Age 24?

Newsy (Apr. 15, 2014) A new study out of Canada says cognitive motor performance begins deteriorating around age 24. Video provided by Newsy
Powered by NewsLook.com
How Mt. Everest Helped Scientists Research Diabetes

How Mt. Everest Helped Scientists Research Diabetes

Newsy (Apr. 15, 2014) British researchers were able to use Mount Everest's low altitudes to study insulin resistance. They hope to find ways to treat diabetes. Video provided by Newsy
Powered by NewsLook.com
Carpenter's Injury Leads To Hundreds Of 3-D-Printed Hands

Carpenter's Injury Leads To Hundreds Of 3-D-Printed Hands

Newsy (Apr. 14, 2014) Richard van As lost all fingers on his right hand in a woodworking accident. Now, he's used the incident to create a prosthetic to help hundreds. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins