Featured Research

from universities, journals, and other organizations

Neuroscientists Identify How Trauma Triggers Long-lasting Memories In The Brain

Date:
August 18, 2005
Source:
University of California - Irvine
Summary:
A research team led by UC Irvine neuroscientists has identified how the brain processes and stores emotional experiences as long-term memories. The research, performed on rats, could help neuroscientists better understand why emotionally arousing events are remembered over longer periods than emotionally neutral events, and may ultimately find application in treatments for conditions such as post-traumatic stress disorder.

Irvine, Calif., July 26, 2005 --A research team led by UC Irvineneuroscientists has identified how the brain processes and storesemotional experiences as long-term memories. The research, performed onrats, could help neuroscientists better understand why emotionallyarousing events are remembered over longer periods than emotionallyneutral events, and may ultimately find application in treatments forconditions such as post-traumatic stress disorder.

Related Articles


The study shows that emotionally arousing events activate thebrain's amygdala, the almond-shaped portion of the brain involved inemotional learning and memory, which then increases a protein called"Arc" in the neurons in the hippocampus, a part of the brain involvedin processing and enabling the storage of lasting memories. Theresearchers believe that Arc helps store these memories bystrengthening the synapses, the connections between neurons.

The study will appear in today's issue of the Proceedings of the National Academy of Sciences.

"Emotionally neutral events generally are not stored aslong-term memories," said Christa McIntyre, the first author of thepaper and a postdoctoral researcher in the Department of Neurobiologyand Behavior in UCI's School of Biological Sciences, working with JamesL. McGaugh, research professor and a fellow at the Center for theNeurobiology of Learning and Memory. "On the other hand, emotionallyarousing events, such as those of September 11, tend to bewell-remembered after a single experience because they activate theamygdala."

In their experiments, the researchers placed a group of rats ina well-lit compartment with access to an adjacent dark compartment.Because rats are nocturnal and prefer dark environments, they tended toenter the dark compartment. Upon doing so, however, they were eachgiven a mild foot-shock -- an emotional experience that, by itself, wasnot strong enough to become a long-lasting memory. Some of the ratsthen had their amygdala chemically stimulated in order to determinewhat role it played in forming a memory of the experience.

When they placed the rats that received both the mildfoot-shock and the amygdala stimulation back in the well-litcompartment, the researchers found the rats tended to remain there,demonstrating a memory for the foot shock they had received in the darkcompartment. These rats, the researchers found, also showed an increasein the amount of the Arc protein in the hippocampus. On the other hand,rats that received only the mild foot-shock and no amygdala stimulationshowed no increase in Arc protein. When placed in the well-litcompartment, they tended to enter the dark compartment, suggesting theydidn't remember the foot shock.

"In a separate experiment, we chemically inactivated theamygdala in rats very soon after they received a strong foot-shock,"McIntyre said. "We found the increase in Arc was reduced and these ratsshowed poor memory for the foot shock despite its high intensity. Thisalso shows that the amygdala is involved in forming a long-termmemory."

The brain is extremely dynamic, McIntyre explained, with somegenes in the brain, called "immediate early genes," changing afterevery experience. "We know the level of the immediate early gene thatmakes the Arc protein increases in the brain, simply in response to anexposure to a new environment," she said. "Our findings show that thisgene makes more Arc protein in the hippocampus only if the experienceis emotionally arousing or important enough to activate the amygdalaand to be remembered days later."

The researchers were surprised to find no change in the genethat produced the Arc protein when the rat's amygdala was stimulated."We weren't expecting the gene to be uncoupled from the Arc protein,"McIntyre said. "We thought an activation of the amygdala would createmore gene activation in the hippocampus. But we saw the same amount ofthe gene in the rats, regardless of the amygdala treatment. It was theArc protein, created by the gene, that was different. This gives us newinsight into the way lasting memories are stored."

The research was supported by several grants from the NationalInstitutes of Health. In addition to McIntyre and McGaugh, co-authorsof the study include Oswald Steward, UCI; Teiko Miyashita, KristopherD. Marjon and John F. Guzowski, the University of New Mexico HealthScience Center; and Barry Setlow, Texas A&M University.



Story Source:

The above story is based on materials provided by University of California - Irvine. Note: Materials may be edited for content and length.


Cite This Page:

University of California - Irvine. "Neuroscientists Identify How Trauma Triggers Long-lasting Memories In The Brain." ScienceDaily. ScienceDaily, 18 August 2005. <www.sciencedaily.com/releases/2005/08/050814175315.htm>.
University of California - Irvine. (2005, August 18). Neuroscientists Identify How Trauma Triggers Long-lasting Memories In The Brain. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2005/08/050814175315.htm
University of California - Irvine. "Neuroscientists Identify How Trauma Triggers Long-lasting Memories In The Brain." ScienceDaily. www.sciencedaily.com/releases/2005/08/050814175315.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Prenatal Exposure To Pollution Might Increase Autism Risk

Prenatal Exposure To Pollution Might Increase Autism Risk

Newsy (Dec. 18, 2014) Harvard researchers found children whose mothers were exposed to high pollution levels in the third trimester were twice as likely to develop autism. 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:

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