Featured Research

from universities, journals, and other organizations

Diffuse brain damage can occur with no signs of 'concussion' in rats, reports study

Date:
March 21, 2014
Source:
Wolters Kluwer Health: Lippincott Williams & Wilkins
Summary:
A standard experimental model of concussion in rats causes substantial brain damage -— but no behavioral changes comparable to those seen in patients with concussion, reports a study. The results highlight the "disconnect" between preclinical and clinical studies of concussion. The study also adds to concerns over the possible long-term effects of repeated, "subconcussive" brain trauma -- causing no concussion symptoms -- in humans.

A standard experimental model of concussion in rats causes substantial brain damage -- but no behavioral changes comparable to those seen in patients with concussion, reports a study in the April issue of Neurosurgery, official journal of the Congress of Neurological Surgeons. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

Related Articles


The results highlight the "disconnect" between preclinical and clinical studies of concussion, according to the report by Dr. Charles L. Rosen of West Virginia University, Morgantown, and colleagues. The study also adds to concerns over the possible long-term effects of repeated, "subconcussive" brain trauma -- causing no concussion symptoms -- in humans.

Despite Diffuse Brain Damage, No Signs of 'Concussion' in Rats

Concussions are thought to be a form of "mild traumatic brain injury." However, there is no definitive diagnostic test to determine when a concussion has occurred. Instead, concussion is diagnosed on the basis of symptoms such as headache, nausea, dizziness, and confusion.

In contrast, animal studies of concussion have focused on directly observed injury to brain tissues, with little attention to the possible behavioral and functional consequences of the brain trauma. Thus there is a "clear disconnect" between experimental and clinical studies of concussion, according to Dr. Rosen and colleagues.

To address this discrepancy, they used a standard technique, called the "impact-acceleration model," to induce brain injury in rats. As reported by previous studies, this technique caused "diffuse axonal injury" to the brain, with visible evidence of damage on the cellular level.

The researchers also compared injured and uninjured animals on a wide range of functional and behavioral tests. The tests were chosen to reflect symptoms and functions similar to those used to diagnose concussion in humans -- for example, locomotor activity, coordination/balance, cognitive function, and anxiety- and depression-like behaviors.

But despite a rather extensive pattern of brain injury, the rats had no significant abnormalities on any of the tests. That was so on the day after brain injury as well as up to one week afterward. "The lack of functional deficits is in sharp contrast to neuropathological findings indicating neural degeneration, astrocyte reactivity, and microglial activation." Dr. Rosen and colleagues write.

Findings Support Concerns about 'Subconcussive Injury'

The new study comes at a time when new researchers are finding evidence of long-term neurodegenerative changes in the brains of people who have never been diagnosed with a concussion. One key study in high school football players found changes in neurological function and health in athletes who never had concussion symptoms, but had sustained "repetitive subconcussive blows."

Traditionally, concussion has been regarded as a temporary problem that resolves with no long-term effects. But that view has changed in recent years, with studies in athletes and others showing chronic traumatic encephalopathy linked to repetitive head injury -- both the concussive and subconcussive types.

The new experiments support the concept that significant brain damage may be present in individuals who have completely normal results on symptom-based assessments currently used to diagnose concussions. Dr. Rosen and coauthors write, "It appears that even subconcussive injury, or injury below the current clinical threshold for detection using standard measures, may have lasting neurological effects."

The researchers emphasize that their short-term study in rats provides no direct evidence of long-term changes caused by "mild" traumatic brain injury in humans. They discuss the need for further research to clarify the effects of traumatic brain injury over time, and to develop new models for understanding the long-term impact of repeated head trauma.


Story Source:

The above story is based on materials provided by Wolters Kluwer Health: Lippincott Williams & Wilkins. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ryan C. Turner, Reyna L. VanGilder, Zachary J. Naser, Brandon P. Lucke-Wold, Julian E. Bailes, Rae R. Matsumoto, Jason D. Huber, Charles L. Rosen. Elucidating the Severity of Preclinical Traumatic Brain Injury Models. Neurosurgery, 2014; 74 (4): 382 DOI: 10.1227/NEU.0000000000000292

Cite This Page:

Wolters Kluwer Health: Lippincott Williams & Wilkins. "Diffuse brain damage can occur with no signs of 'concussion' in rats, reports study." ScienceDaily. ScienceDaily, 21 March 2014. <www.sciencedaily.com/releases/2014/03/140321101401.htm>.
Wolters Kluwer Health: Lippincott Williams & Wilkins. (2014, March 21). Diffuse brain damage can occur with no signs of 'concussion' in rats, reports study. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2014/03/140321101401.htm
Wolters Kluwer Health: Lippincott Williams & Wilkins. "Diffuse brain damage can occur with no signs of 'concussion' in rats, reports study." ScienceDaily. www.sciencedaily.com/releases/2014/03/140321101401.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Tryptophan Isn't Making You Sleepy On Thanksgiving

Tryptophan Isn't Making You Sleepy On Thanksgiving

Newsy (Nov. 27, 2014) — Tryptophan, a chemical found naturally in turkey meat, gets blamed for sleepiness after Thanksgiving meals. But science points to other culprits. Video provided by Newsy
Powered by NewsLook.com
Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) — A new study links greater authority with increased depressive symptoms among women in the workplace. Video provided by Newsy
Powered by NewsLook.com
Winter Can Cause Depression — Here's How To Combat It

Winter Can Cause Depression — Here's How To Combat It

Newsy (Nov. 23, 2014) — Millions of American suffer from seasonal depression every year. It can lead to adverse health effects, but there are ways to ease symptoms. Video provided by Newsy
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) — Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. 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