Featured Research

from universities, journals, and other organizations

Far-reaching, microvascular damage found in uninjured side of brain after stroke

Date:
May 20, 2013
Source:
University of South Florida (USF Health)
Summary:
An animal-model study finds far-reaching microvascular damage in the uninjured side of the brain after a stroke. The findings suggest repair of the protective blood-brain barrier may help prevent this breach in the days following the acute injury.

While the effects of acute stroke have been widely studied, brain damage during the subacute phase of stroke has been a neglected area of research. Now, a new study by the University of South Florida reports that within a week of a stroke caused by a blood clot in one side of the brain, the opposite side of the brain shows signs of microvascular injury.

Related Articles


Stroke is a leading cause of death and disability in the United States, and increases the risk for dementia.

"Approximately 80 percent of strokes are ischemic strokes, in which the blood supply to the brain is restricted, causing a shortage of oxygen," said study lead author Svitlana Garbuzova-Davis, PhD, associate professor in the USF Department of Neurosurgery and Brain Repair. "Minutes after ischemic stroke, there are serious effects within the brain at both the molecular and cellular levels. One understudied aspect has been the effect of ischemic stroke on the competence of the blood-brain barrier and subsequent related events in remote brain areas."

Using a rat model, researchers at USF Health investigated the subacute phase of ischemic stroke and found deficits in the microvascular integrity in the brain hemisphere opposite to where the initial stroke injury occured.

The study was published in the May 10, 2013 issue of PLOS One.

The USF team found that "diachisis," a term used to describe certain brain deficits remote from primary insult, can occur during the subacute phase of ischemic stroke. The research discovered diachisis is closely related to a breakdown of the blood-brain barrier, which separates circulating blood from brain tissue.

In the subacute phase of an ischemic stroke, when the stroke-induced disturbances in the brain occur in remote brain microvessels, several areas of the brain are affected by a variety of injuries, including neuronal swelling and diminished myelin in brain structures. The researchers suggest that recognizing the significance of microvascular damage could make the blood-brain barrier (BBB) a therapeutic "target" for future neuroprotective strategies for stroke patients.

The mechanisms of BBB permeability at different phases of stroke are poorly understood. While there have been investigations of BBB integrity and processes in ischemic stroke, the researchers said, most examinations have been limited to the phase immediately after stroke, known as acute stroke. Their interest was in determining microvascular integrity in the brain hemisphere opposite to an initial stroke injury at the subacute phase.

Accordingly, this study using rats with surgically-simulated strokes was designed to investigate the effect of ischemic stroke on the BBB in the subacute phase, and the effects of a compromised BBB upon various brain regions, some distant from the stroke site.

"The aim of this study was to characterize subacute diachisis in rats modeled with ischemic stroke," said co-author Cesar Borlongan, PhD, professor and vice chairman for research in the Department of Neurosurgery and Brain Repair and director of the USF Center for Aging and Brain Repair. "Our specific focus was on analyzing the condition of the BBB and the processes in the areas of the brain not directly affected by ischemia. BBB competence in subacute diachisis is uncertain and needed to be studied."

Their findings suggest that damage to the BBB, and subsequent vascular leakage as the BBB becomes more permeable, plays a major role in subacute diachisis.

The increasing BBB permeability hours after the simulated stroke, and finding that the BBB "remained open" seven days post-stroke, were significant findings, said Dr. Garbuzova-Davis, who is also a researcher in USF Center for Aging and Brain Repair. "Since increased BBB permeability is often associated with brain swelling, BBB leakage may be a serious and life-threatening complication of ischemic stroke."

Another significant aspect was the finding that autophagy -- a mechanism involving cell degradation of unnecessary or dysfunctional cellular components --plays a role in the subacute phase of ischemia. Study results showed that accumulation of numerous autophagosomes within endothelial cells in microvessels of both initially damaged and non-injured brain areas might be closely associated with BBB damage.

Autophagy is a complex but normal process usually aimed at "self-removing" damaged cell components to promote cell survival. It was unclear, however, whether the role of autophagy in subacute post-ischemia was promoting cell survival or cell death.

More than 30 percent of patients who survive strokes develop dementia within two years, the researchers noted.

"Although dementia is complex, vascular damage in post-stroke patients is a significant risk factor, depending on the severity, volume and site of the stroke," said study co-author Dr. Paul Sanberg, USF senior vice president for research and innovation. "Ischemic stroke might initiate neurodegenerative dementia, particularly in the aging population."

The researchers conclude that repair of the BBB following ischemic stroke could potentially prevent further degradation of surviving neurons.

"Recognizing that the BBB is a therapeutic target is important for developing neuroprotective strategies," they said.


Story Source:

The above story is based on materials provided by University of South Florida (USF Health). Note: Materials may be edited for content and length.


Journal Reference:

  1. Svitlana Garbuzova-Davis, Maria C. O. Rodrigues, Diana G. Hernandez-Ontiveros, Naoki Tajiri, Aric Frisina-Deyo, Sean M. Boffeli, Jerry V. Abraham, Mibel Pabon, Andrew Wagner, Hiroto Ishikawa, Kazutaka Shinozuka, Edward Haller, Paul R. Sanberg, Yuji Kaneko, Cesario V. Borlongan. Blood-Brain Barrier Alterations Provide Evidence of Subacute Diaschisis in an Ischemic Stroke Rat Model. PLoS ONE, 2013; 8 (5): e63553 DOI: 10.1371/journal.pone.0063553

Cite This Page:

University of South Florida (USF Health). "Far-reaching, microvascular damage found in uninjured side of brain after stroke." ScienceDaily. ScienceDaily, 20 May 2013. <www.sciencedaily.com/releases/2013/05/130520133747.htm>.
University of South Florida (USF Health). (2013, May 20). Far-reaching, microvascular damage found in uninjured side of brain after stroke. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/2013/05/130520133747.htm
University of South Florida (USF Health). "Far-reaching, microvascular damage found in uninjured side of brain after stroke." ScienceDaily. www.sciencedaily.com/releases/2013/05/130520133747.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Technology Is Ruining Snow Days For Students

How Technology Is Ruining Snow Days For Students

Newsy (Jan. 25, 2015) — More schools are using online classes to keep from losing time to snow days, but it only works if students have Internet access at home. Video provided by Newsy
Powered by NewsLook.com
Weird Things Couples Do When They Lose Their Phone

Weird Things Couples Do When They Lose Their Phone

BuzzFeed (Jan. 24, 2015) — Did you back it up? Do you even know how to do that? Video provided by BuzzFeed
Powered by NewsLook.com
Smart Wristband to Shock Away Bad Habits

Smart Wristband to Shock Away Bad Habits

Reuters - Innovations Video Online (Jan. 23, 2015) — A Boston start-up is developing a wristband they say will help users break bad habits by jolting them with an electric shock. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Amazing Technology Allows Blind Mother to See Her Newborn Son

Amazing Technology Allows Blind Mother to See Her Newborn Son

RightThisMinute (Jan. 23, 2015) — Not only is Kathy seeing her newborn son for the first time, but this is actually the first time she has ever seen a baby. Kathy and her sister, Yvonne, have been legally blind since childhood, but thanks to an amazing new technology, eSight glasses, which gives those who are legally blind the ability to see, she got the chance to see the birth of her son. It&apos;s an incredible moment and an even better story. Video provided by RightThisMinute
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