Featured Research

from universities, journals, and other organizations

Nurturing newborn neurons sharpens minds in mice

Date:
April 4, 2011
Source:
NIH/National Institute of Mental Health
Summary:
Adult mice engineered to have more newborn neurons in their brain memory hub excelled at accurately discriminating between similar experiences -- an ability that declines with normal aging and in some anxiety disorders. Boosting such neurogenesis in the adult hippocampus also produced antidepressant-like effects when combined with exercise. The study pinpointed effects of enhanced adult neurogenesis by creating mice lacking a gene required for programmed cell death of newborn neurons in the adult hippocampus.

Adult mice engineered to have more newborn neurons in their brain memory hub excelled at accurately discriminating between similar experiences -- an ability that declines with normal aging and in some anxiety disorders. Boosting such neurogenesis in the adult hippocampus also produced antidepressant-like effects when combined with exercise, in the study funded by the National Institutes of Health.

Researchers, for the first time, pinpointed the effects of enhanced adult neurogenesis by creating mice lacking a gene required for programmed cell death of newborn neurons in the adult hippocampus.

"These mice with more young neurons were better at recognizing patterns -- tasks that become more challenging as we age," explained Rene Hen Ph.D., of Columbia University in New York City. "A deficit in this ability can also contribute to anxiety, as over-generalization sometimes leads to mistaking ambiguous cues as threatening. Our study demonstrates that the stimulation of adult neurogenesis is sufficient to improve such pattern recognition behavior, but, while necessary, not sufficient to lift depression-like behavior."

Hen and Amar Sahay, Ph.D., grantees of the NIH's National Institute of Mental Health (NIMH), and colleagues, report on their discovery online April 3, 2011, in the journal Nature.

"By helping to disentangle effects of enhanced neurogenesis on cognition from those on mood, this study brings us closer to understanding how it might be harnessed in the service of better treatments for disorders like depression, post traumatic stress syndrome and panic disorder, as well as for cognitive decline," said NIMH Director Thomas R. Insel, M.D.

In earlier studies, Hen and colleagues had shown that birth of new neurons in the hippocampus was necessary for the therapeutic effects of current antidepressant medications. Since it takes weeks for these cells to grow and become integrated into brain circuits, this helped to explain the delay in symptom improvement experienced by patients. Evidence has also emerged that environmental enrichment and exercise can also stimulate neurogenesis and produce antidepressant-like effects. Yet the exact contributions of increased adult neurogenesis remained elusive.

To identify them, the researchers used genetic engineering to create mice lacking a gene that normally kills off 50-80 percent of newborn neurons in the adult hippocampus. These mice with a relative surplus of adult-born neurons were champs at learning to discriminate between a chamber where they had previously received a foot shock and a similar-looking chamber that was safe. By contrast, mice in which adult hippocampal neurogenesis was blocked performed poorly at this fear discrimination learning task, often freezing in safe chambers.

Yet, the mice with genetically enhanced adult neurogenesis did not show improved anti-anxiety or antidepressant-like behaviors, such as increased exploration in anxiety-producing situations. Such behaviors emerged in these mice only after four weeks of wheel running exercise, suggesting that neurogenesis might need to be accompanied by some kind of environmental enhancement to produce such effects.

Hen and Sahay said they are now using neuronal growth factors in combination with enhanced neurogenesis to explore possible mechanisms underlying such anti-anxiety and antidepressant effects. They are also weighing emerging evidence that neurogenesis in the bottom part of the hippocampus influences mood and anxiety-related behaviors, while neurogenesis in the top part of the mouse brain structure may have more to do with thinking and memory.


Story Source:

The above story is based on materials provided by NIH/National Institute of Mental Health. Note: Materials may be edited for content and length.


Journal Reference:

  1. Amar Sahay, Kimberly N. Scobie, Alexis S. Hill, Colin M. O'Carroll, Mazen A. Kheirbek, Nesha S. Burghardt, Andrι A. Fenton, Alex Dranovsky, Renι Hen. Increasing adult hippocampal neurogenesis is sufficient to improve pattern separation. Nature, 2011; DOI: 10.1038/nature09817

Cite This Page:

NIH/National Institute of Mental Health. "Nurturing newborn neurons sharpens minds in mice." ScienceDaily. ScienceDaily, 4 April 2011. <www.sciencedaily.com/releases/2011/04/110403141634.htm>.
NIH/National Institute of Mental Health. (2011, April 4). Nurturing newborn neurons sharpens minds in mice. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2011/04/110403141634.htm
NIH/National Institute of Mental Health. "Nurturing newborn neurons sharpens minds in mice." ScienceDaily. www.sciencedaily.com/releases/2011/04/110403141634.htm (accessed September 22, 2014).

Share This



More Mind & Brain News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) — The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Food Addiction Might Be Caused By PTSD

Food Addiction Might Be Caused By PTSD

Newsy (Sep. 18, 2014) — New research shows that women who suffer from PTSD are three times more likely to develop a food addiction. Video provided by Newsy
Powered by NewsLook.com
Corporal Punishment on Decline, Debate Renews

Corporal Punishment on Decline, Debate Renews

AP (Sep. 16, 2014) — Corporal punishment in the United States is on the decline, but there is renewed debate over its use after Minnesota Vikings running back Adrian Peterson was charged with child abuse. (Sept. 16) Video provided by AP
Powered by NewsLook.com
FDA Eyes Skin Shocks Used at Mass. School

FDA Eyes Skin Shocks Used at Mass. School

AP (Sep. 15, 2014) — The FDA is considering whether to ban devices used by the Judge Rotenberg Educational Center in Canton, Massachusetts, the only place in the country known to use electrical skin shocks as aversive conditioning for aggressive patients. (Sept. 15) Video provided by AP
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