Featured Research

from universities, journals, and other organizations

Double-Edged Effect Of Inflammatory Response Discovered After Brain Injury

Date:
July 23, 1999
Source:
University Of Pennsylvania Medical Center
Summary:
Until recently, researchers in the area of head trauma have only concentrated on the biochemical sequence of events in the first few days after an injury. During the past year, however, investigators at the University of Pennsylvania Medical Center have found that the brain undergoes enormous changes for months following the initial damage.

Until recently, researchers in the area of head trauma have only concentrated on the biochemical sequence of events in the first few days after an injury. During the past year, however, investigators at the University of Pennsylvania Medical Center have found that the brain undergoes enormous changes for months following the initial damage. In the latest development in this ongoing work, the team found that tumor necrosis factor (TNF) -- a cytokine molecule that is normally released during inflammation -- may be damaging and then protective to brain-injured tissue, depending on the time course after the injury. The researchers report their findings in this week's issue of the Proceedings of the National Academy of Sciences.

Related Articles


The study has clear ramifications for treating brain trauma. "In the very early stages after head injury TNF may be harmful, so we'll probably want to block it with drugs, if possible," says Tracy K. McIntosh, PhD, professor of neurosurgery, bioengineering, and pharmacology and director of the Head Injury Center at Penn. "But if you continue to block or antagonize its effects, you may be doing some damage because it appears that in the chronic stages, TNF is important for recovery."

Using genetically engineered mice deficient in TNF, the team found that 48 hours after injury the TNF-knockout mice were less neurologically impaired than injured normal mice in tests of strength, balance, and coordination. The same held true for mice who underwent tests for memory retention seven days post-injury. But, by two to three weeks after the injury the normal mice recovered; whereas, TNF-knockout mice continued to show persistent motor deficits until at least four weeks, the length of the study. Over the long term, the TNF knockouts also had more cortical tissue loss than the normal mice.

"These findings bear out our hypothesis that in the acute period TNF is harmful to the brain, but in chronic stages TNF may play an important and beneficial role," notes McIntosh. Neuroscientists have long thought that inflammatory cytokines like TNFs are deleterious to the brain in terms of promoting neurodegeneration, much like that seen in stroke, Alzheimer's, and Parkinson's disease patients. On the other hand, in recent studies TNFs have also been implicated in such regenerative processes as wound-healing, nerve repair, and antioxidant pathways.

Although this study was aimed at probing the role of TNF in brain injury, it does hold potential lessons for treatment. "A drug company could conceivably develop a pharmacological strategy to block TNF, which could be given to head injury patients during the acute injury phase," says McIntosh. But the study also cautions that if a TNF blockade is continued into the chronic, post-traumatic phase, it could be harmful. The drug therapy would have to be discontinued so that TNF naturally present in the brain could promote long-term regeneration.

In addition to TNF, the McIntosh lab is studying another inflammatory cytokine. In a report to be published later this, the group analyzed the therapeutic value of an interleukin-1 receptor antagonist. By simply blocking interleukin-1 pharmacologically, memory loss and cell death were minimized in brain-injured rats.

Penn coauthors are Uwe Scherbel, Ramesh Raghupathi, Michio Nakamura, Kathryn Saatman, and John Trojanowski. These studies were funded in part by grants from the National Institutes of Health and the Veteran's Administration.


Story Source:

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


Cite This Page:

University Of Pennsylvania Medical Center. "Double-Edged Effect Of Inflammatory Response Discovered After Brain Injury." ScienceDaily. ScienceDaily, 23 July 1999. <www.sciencedaily.com/releases/1999/07/990723083745.htm>.
University Of Pennsylvania Medical Center. (1999, July 23). Double-Edged Effect Of Inflammatory Response Discovered After Brain Injury. ScienceDaily. Retrieved April 19, 2015 from www.sciencedaily.com/releases/1999/07/990723083745.htm
University Of Pennsylvania Medical Center. "Double-Edged Effect Of Inflammatory Response Discovered After Brain Injury." ScienceDaily. www.sciencedaily.com/releases/1999/07/990723083745.htm (accessed April 19, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Sunday, April 19, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Our Love Of Puppy Dog Eyes Explained By Science

Our Love Of Puppy Dog Eyes Explained By Science

Newsy (Apr. 17, 2015) Researchers found a spike in oxytocin occurs in both humans and dogs when they gaze into each other&apos;s eyes. Video provided by Newsy
Powered by NewsLook.com
Scientists Find Link Between Gestational Diabetes And Autism

Scientists Find Link Between Gestational Diabetes And Autism

Newsy (Apr. 17, 2015) Researchers who analyzed data from over 300,000 kids and their mothers say they&apos;ve found a link between gestational diabetes and autism. Video provided by Newsy
Powered by NewsLook.com
Video Messages Help Reassure Dementia Patients

Video Messages Help Reassure Dementia Patients

AP (Apr. 17, 2015) Family members are prerecording messages as part of a unique pilot program at the Hebrew Home in New York. The videos are trying to help victims of Alzheimer&apos;s disease and other forms of dementia break through the morning fog of forgetfulness. (April 17) Video provided by AP
Powered by NewsLook.com
Common Pain Reliever Might Dull Your Emotions

Common Pain Reliever Might Dull Your Emotions

Newsy (Apr. 16, 2015) Each week, millions of Americans take acetaminophen to dull minor aches and pains. Now researchers say it might blunt life&apos;s highs and lows, too. 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