Featured Research

from universities, journals, and other organizations

How brain's memory center repairs damage from head injury

Date:
April 1, 2011
Source:
UT Southwestern Medical Center
Summary:
Researchers have described for the first time how the brain's memory center repairs itself following severe trauma.

Researchers from UT Southwestern Medical Center have described for the first time how the brain's memory center repairs itself following severe trauma -- a process that may explain why it is harder to bounce back after multiple head injuries.

Related Articles


The study, published in The Journal of Neuroscience, reports significant learning and memory problems in mice who were unable to create new nerve cells in the brain's memory area, the hippocampus, following brain trauma. The study's senior author, Dr. Steven G. Kernie, associate professor of pediatrics and developmental biology at UT Southwestern, said the hippocampus contains a well of neural stem cells that become neurons in response to injury; those stem cells must grow into functioning nerve cells to mend the damage.

"Traumatic brain injury (TBI) has received a lot of attention recently because of the recognition that both military personnel and football players suffer from debilitating brain injuries," Dr. Kernie said, adding that memory and learning problems are common after repeated severe head injuries.

"We have discovered that neural stem cells in the brain's memory area become activated by injury and remodel the area with newly generated nerve cells," Dr. Kernie said. "We also found that the activation of these stem cells is required for recovery."

The scientists developed unique transgenic mice that were unable to create hippocampal neurons when exposed to a usually harmless chemical called ganciclovir soon after brain injury. Four groups of these transgenic mice received either sham surgery or a controlled cortical injury (CCI) to mimic the diffuse damage of a moderate to severe head injury, and two of the groups were exposed to ganciclovir, Dr. Kernie said.

After a month -- the time earlier experiments indicated it takes for neural stem cells to mature and integrate as neurons into the hippocampus -- the researchers gave the mice a learning task called the Morris water maze in which the mice had to find a white platform hidden in a white pool of water. On the first day of learning the task, there were no group-noteworthy differences in swim speed, indicating no motor impairment in the test mice. During the next 10 days, however, the test group spent more time swimming along the edges of the tank, and they traveled longer distances to reach the platform.

"This suggests that injured mice who lack new nerve cells fail to progress to a more efficient spatial strategy to find the hidden platform. We interpret this result as a mild but statistically significant learning deficit," he said.

The UT Southwestern scientists then let the mice rest a day, removed the platform and retested them to see how well they remembered where the platform's location.

Compared to controls, CCI mice showed no preference for the platform's previous location or even for the target quadrant of the pool where the platform had been, Dr. Kernie said.

In comparison, CCI mice with intact nerve cell generation had an intermediate response to the water maze and non-CCI mice with intact nerve cell generation had the best response. Dr. Kernie said those findings suggest that neurogenesis is necessary for learning after TBI, and they raise the question of whether the neural stem cell pool is limited.

"The ability to self-repair may be limited," he said.

Since there are already Food and Drug Administration-approved medications available to increase neurogenesis, the next steps are to determine if these can be used to improve outcomes after traumatic brain injuries. In addition, Dr. Kernie and colleagues are determining what molecules direct this process and how the stem cell pool might be preserved in order to enhance the ability to recover from recurrent injury.

Other UT Southwestern researchers involved in the study were lead author Dr. Cory Blaiss, a former postdoctoral researcher who now is an assistant research scientist at the Ernest Gallo Clinic and Research Center at the University of California, San Francisco; Dr. Tzong-Shiue Yu, former graduate student who now is a postdoctoral researcher at Toronto Hospital for Sick Children; Gui Zhang, research assistant in pediatrics; Georgi Dimchev, former graduate student presently enrolled at Manchester Metropolitan University in England; Dr. Luis Parada, chairman of developmental biology; and Dr. Craig Powell, assistant professor of neurology and neurotherapeutics and psychiatry.

The research was funded by the National Institutes of Health, the Seay Endowed Fund for Research on Brain and Spinal Cord Injuries in Children, the National Institutes of Mental Health, the National Institute of Child Health and Human Development, and the Hartwell Foundation.


Story Source:

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


Journal Reference:

  1. C. A. Blaiss, T.-S. Yu, G. Zhang, J. Chen, G. Dimchev, L. F. Parada, C. M. Powell, S. G. Kernie. Temporally Specified Genetic Ablation of Neurogenesis Impairs Cognitive Recovery after Traumatic Brain Injury. Journal of Neuroscience, 2011; 31 (13): 4906 DOI: 10.1523/JNEUROSCI.5265-10.2011

Cite This Page:

UT Southwestern Medical Center. "How brain's memory center repairs damage from head injury." ScienceDaily. ScienceDaily, 1 April 2011. <www.sciencedaily.com/releases/2011/03/110331094617.htm>.
UT Southwestern Medical Center. (2011, April 1). How brain's memory center repairs damage from head injury. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2011/03/110331094617.htm
UT Southwestern Medical Center. "How brain's memory center repairs damage from head injury." ScienceDaily. www.sciencedaily.com/releases/2011/03/110331094617.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Yoga Could Be As Beneficial For The Heart As Walking, Biking

Yoga Could Be As Beneficial For The Heart As Walking, Biking

Newsy (Dec. 17, 2014) Yoga can help your weight, blood pressure, cholesterol and heart just as much as biking and walking does, a new study suggests. Video provided by Newsy
Powered by NewsLook.com
1st Responders Trained for Autism Sensitivity

1st Responders Trained for Autism Sensitivity

AP (Dec. 16, 2014) More departments are ordering their first responders to sit in on training sessions that focus on how to more effectively interact with those with autism spectrum disorder (Dec. 16) Video provided by AP
Powered by NewsLook.com
Guys Are Idiots, According To Sarcastic Study

Guys Are Idiots, According To Sarcastic Study

Newsy (Dec. 12, 2014) A study out of Britain suggest men are more idiotic than women based on the rate of accidental deaths and other factors. Video provided by Newsy
Powered by NewsLook.com
Believing in Father Christmas Good for Children's Imaginations

Believing in Father Christmas Good for Children's Imaginations

AFP (Dec. 12, 2014) As the countdown to Christmas gets underway, so too does the Father Christmas conspiracy. But psychologists say that telling our children about Santa, flying reindeer and elves is good for their imaginations. Duration: 01:57 Video provided by AFP
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