Featured Research

from universities, journals, and other organizations

In learning, the brain forgets things on purpose

Date:
February 19, 2010
Source:
Cell Press
Summary:
Scientists have known that newly acquired, short-term memories are often fleeting. But a new study in flies suggests that kind of forgetfulness doesn't just happen. Rather, an active process of erasing memories may in some ways be as important as the ability to lay down new memories.

Scientists have known that newly acquired, short-term memories are often fleeting. But a new study in flies suggests that kind of forgetfulness doesn't just happen. Rather, an active process of erasing memories may in some ways be as important as the ability to lay down new memories, say researchers who report their findings in the February 19th issue of the journal Cell.

Related Articles


"Learning activates the biochemical formation of memory," says Yi Zhong of Tsinghua University and Cold Spring Harbor Laboratory. "But you need to remove memories for new information to come in. We've found that forgetting is an active process to remove memory."

The researchers have traced that process to a molecular pathway including a small protein known as Rac. When that mechanism is blocked, flies hold on to newly acquired memories for longer than they otherwise would.

At the psychological level, scientists have debated about the reasons we forget. One theory held that new memories are simply unstable and evaporate over time. On the other hand, some thought that interference caused earlier short-term memories to be overridden as new information comes in.

Now it appears that those competing notions are, at the molecular level at least, one and the same.

Zhong's team made their discovery by training flies with two aversive odors. To add to the aversion with one of the two odors, the researchers delivered a foot shock to the insects as they smelled it. That education normally leads flies to avoid the odor associated with a shock in favor of the alternative.

In the first set of experiments, the researchers simply left the flies alone after their training session was over and then tested them at particular time points as their memory weakened. In a second experiment, the researchers interfered with the new memories by exposing flies to a new pair of odors. Finally, they reversed the flies' lesson by delivering the foot shock in conjunction with the opposite odor.

In all cases, the flies forgot what they learned after some period of time in a process driven by Rac. Rac switches on when flies simply forget with the passage of time, they report. It just switches on faster when the insects either get distracted by new information or "confused" by conflicting experiences. When Rac was blocked, new memories decayed more slowly, extending their life from a few hours to more than a day. When Rac levels were artificially increased in fly neurons, the insects' new memories were erased more rapidly.

The findings open up a whole new avenue of study in neuroscience of the process of forgetting, Zhong said. Ironically, this line of exploration may turn out to reveal much about how memories are made.

"We still don't really understand the substrate of memory in terms of what is formed and what is erased," Zhong said. "The study of forgetting may be a better way to identify the material basis of memory."

He suspects the forgetting mechanism uncovered in flies will apply to other organisms, noting that there are already some hints in that direction in mice. Intriguingly, mutations in other players in the Rac pathway have also been linked to mental retardation in humans, he said.

The researchers include Yichun Shuai, Tsinghua University, Beijing, P.R. China; Binyan Lu, Tsinghua University, Beijing, P.R. China; Ying Hu, Tsinghua University, Beijing, P.R. China; Lianzhang Wang, Tsinghua University, Beijing, P.R. China; Kan Sun, Tsinghua University, Beijing, P.R. China; and Yi Zhong, Tsinghua University, Beijing, P.R. China, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Cite This Page:

Cell Press. "In learning, the brain forgets things on purpose." ScienceDaily. ScienceDaily, 19 February 2010. <www.sciencedaily.com/releases/2010/02/100218125149.htm>.
Cell Press. (2010, February 19). In learning, the brain forgets things on purpose. ScienceDaily. Retrieved January 24, 2015 from www.sciencedaily.com/releases/2010/02/100218125149.htm
Cell Press. "In learning, the brain forgets things on purpose." ScienceDaily. www.sciencedaily.com/releases/2010/02/100218125149.htm (accessed January 24, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Saturday, January 24, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Smart Wristband to Shock Away Bad Habits

Smart Wristband to Shock Away Bad Habits

Reuters - Innovations Video Online (Jan. 23, 2015) — A Boston start-up is developing a wristband they say will help users break bad habits by jolting them with an electric shock. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Amazing Technology Allows Blind Mother to See Her Newborn Son

Amazing Technology Allows Blind Mother to See Her Newborn Son

RightThisMinute (Jan. 23, 2015) — Not only is Kathy seeing her newborn son for the first time, but this is actually the first time she has ever seen a baby. Kathy and her sister, Yvonne, have been legally blind since childhood, but thanks to an amazing new technology, eSight glasses, which gives those who are legally blind the ability to see, she got the chance to see the birth of her son. It&apos;s an incredible moment and an even better story. Video provided by RightThisMinute
Powered by NewsLook.com
One Dose, Then Surgery to Test Tumor Drugs Fast

One Dose, Then Surgery to Test Tumor Drugs Fast

AP (Jan. 23, 2015) — A Phoenix hospital is experimenting with a faster way to test much needed medications for deadly brain tumors. Patients get a single dose of a potential drug, and hours later have their tumor removed to see if the drug had any affect. (Jan. 23) Video provided by AP
Powered by NewsLook.com
The Best Bedtime Rituals For a Good Night's Sleep

The Best Bedtime Rituals For a Good Night's Sleep

Buzz60 (Jan. 22, 2015) — What you do before bed can effect how well you sleep. TC Newman (@PurpleTCNewman) has bedtime rituals to induce the best night&apos;s sleep. Video provided by Buzz60
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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