Featured Research

from universities, journals, and other organizations

Sleep mechanism identified that plays role in emotional memory

Date:
June 12, 2013
Source:
University of California, Riverside
Summary:
Sleep researchers have identified the sleep mechanism that enables the brain to consolidate emotional memory and found that a popular prescription sleep aid heightens the recollection of and response to negative memories.

Sleep researchers have identified the sleep mechanism that enables the brain to consolidate emotional memory and found that a popular prescription sleep aid heightens the recollection of and response to negative memories.
Credit: Africa Studio / Fotolia

Sleep researchers from University of California campuses in Riverside and San Diego have identified the sleep mechanism that enables the brain to consolidate emotional memory and found that a popular prescription sleep aid heightens the recollection of and response to negative memories.

Their findings have implications for individuals suffering from insomnia related to posttraumatic stress disorder (PTSD) and other anxiety disorders who are prescribed zolpidem (Ambien) to help them sleep.

The study -- "Pharmacologically Increasing Sleep Spindles Enhances Recognition for Negative and High-arousal Memories" -- appears in the Journal of Cognitive Neuroscience.

Mednick and UC San Diego psychologists Erik J. Kaestner and John T. Wixted determined that a sleep feature known as sleep spindles -- bursts of brain activity that last for a second or less during a specific stage of sleep -- are important for emotional memory.

Research Mednick published earlier this year demonstrated the critical role that sleep spindles play in consolidating information from short-term to long-term memory in the hippocampus, located in the cerebral cortex of the brain. Zolpidem enhanced the process, a discovery that could lead to new sleep therapies to improve memory for aging adults and those with dementia, Alzheimer's and schizophrenia. It was the first study to show that sleep can be manipulated with pharmacology to improve memory.

"We know that sleep spindles are involved in declarative memory -- explicit information we recall about the world, such as places, people and events, " she explained.

But until now, researchers had not considered sleep spindles as playing a role in emotional memory , focusing instead on rapid eye movement (REM) sleep.

Using two commonly prescribed sleep aids -- zolpidem and sodium oxybate (Xyrem) -- Mednick, Kaestner and Wixted were able to tease apart the effects of sleep spindles and rapid eye movement (REM) sleep on the recall of emotional memories. They determined that sleep spindles, not REM, affect emotional memory.

The researchers gave zolpidem, sodium oxybate (Xyrem) and a placebo to 28 men and women between the ages of 18 and 39 who were normal sleepers, allowing several days between doses to allow the pharmaceuticals to leave their bodies. The participants viewed standardized images known to elicit positive and negative responses for one second before and after taking supervised naps. They recalled more images that had negative or highly arousing content after taking zolpidem, a finding that also suggests that the brain may favor consolidation of negative memories, she said.

"I was surprised by the specificity of the results, that the emotional memory improvement was specifically for the negative and high-arousal memories, and the ramifications of these results for people with anxiety disorders and PTSD," Mednick said. "These are people who already have heightened memory for negative and high-arousal memories. Sleep drugs might be improving their memories for things they don't want to remember."

The study may have even broader implications, the researchers said. Clinical guidelines of the U.S. Department of Veterans Affairs and Department of Defense recommend against the routine use of benzodiazepines to treat PTSD, although their use increased among men and women with PTSD between 2003 and 2010. The effects of benzodiazepines on sleep are similar to those of zolpidem.

The U.S. Air Force uses zolpidem as one of the prescribed "no-go pills" to help flight crews calm down after taking stimulants to stay awake during long missions, the researchers noted in the study.

"In light of the present results, it would be worthwhile to investigate whether the administration of benzodiazepine-like drugs may be increasing the retention of highly arousing and negative memories, which would have a countertherapeutic effect," they wrote. "Further research on the relationship between hypnotics and emotional mood disorders would seem to be in order."

This study was funded by a National Institutes of Health career award to Sara C. Mednick, assistant professor of psychology at UC Riverside, of $651,999 over five years.


Story Source:

The above story is based on materials provided by University of California, Riverside. The original article was written by Bettye Miller. Note: Materials may be edited for content and length.


Cite This Page:

University of California, Riverside. "Sleep mechanism identified that plays role in emotional memory." ScienceDaily. ScienceDaily, 12 June 2013. <www.sciencedaily.com/releases/2013/06/130612224140.htm>.
University of California, Riverside. (2013, June 12). Sleep mechanism identified that plays role in emotional memory. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2013/06/130612224140.htm
University of California, Riverside. "Sleep mechanism identified that plays role in emotional memory." ScienceDaily. www.sciencedaily.com/releases/2013/06/130612224140.htm (accessed August 21, 2014).

Share This




More Health & Medicine News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Reasons Why Teen Birth Rates Are At An All-Time Low

Reasons Why Teen Birth Rates Are At An All-Time Low

Newsy (Aug. 20, 2014) A CDC report says birth rates among teenagers have been declining for decades, reaching a new low in 2013. We look at several popular explanations. 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