Featured Research

from universities, journals, and other organizations

Link between brain chemical, cognitive decline in schizophrenia demonstrated

Date:
March 11, 2010
Source:
University of California - Davis - Health System
Summary:
In one of the first such studies involving human patients with schizophrenia, researchers have provided evidence that deficits in a brain chemical may be responsible for some of the debilitating cognitive deficits -- poor attention, memory and problem-solving abilities -- that accompany the delusions and hallucinations that are the hallmarks of the disorder.

In one of the first such studies involving human patients with schizophrenia, researchers at UC Davis have provided evidence that deficits in a brain chemical may be responsible for some of the debilitating cognitive deficits -- poor attention, memory and problem-solving abilities -- that accompany the delusions and hallucinations that are the hallmarks of the disorder.

Related Articles


The study, published online March 10 in the Journal of Neuroscience, suggests an important avenue of inquiry for improving cognitive function in the more than 2 million Americans who suffer from schizophrenia, according to Jong H. Yoon, an assistant professor of psychiatry and behavioral sciences at UC Davis Health System and the study's lead author.

"We still know very little about the neurobiology of schizophrenia, particularly at the level of specific circuits and molecules and how their impairments affect behavior and cognition in the disease," said Yoon, a researcher at the UC Davis Imaging Research Center. "We need this level of specificity to guide targeted treatment development. This is one of the first studies to show that there is a strong association between cognitive deficits and a decrease in a particular neurotransmitter."

Schizophrenia is characterized by psychosis -- abnormalities in the perception or expression of reality. Sufferers may experience visual or auditory hallucinations and have paranoia, delusions and disorganized speech and thinking. But they also experience profound cognitive difficulties that interfere with daily functioning.

Psychosis is treated with a variety of antipsychotic medications that dampen overactivity of the neurotransmitter dopamine, an acknowledged cause of psychotic behavior. But no medications are available to address cognitive deficits in schizophrenia because the source of the deficits has not been determined. Deficits in one brain chemical, the neurotransmitter gamma-aminobutyric acid, or GABA, have been implicated as playing a causal role in cognitive difficulties in people with schizophrenia in research involving animal models and post-mortem analyses of GABA concentrations in human schizophrenic brains.

"People think of schizophrenia as being related to psychosis. But patients' cognitive limitations can be even more debilitating for them," said Cameron Carter, professor of psychiatry and behavioral sciences, director of the Imaging Research Center and the study's senior author. "This study actually looked at brain chemistry in live patients in relation to cognitive performance to determine the underlying neurobiology of the cognitive deficits. Our ultimate goal is discovering ways to help patients lead more productive lives."

Yoon and his colleagues measured the levels of GABA in the visual cortexes of the brains of 13 study subjects with schizophrenia and 13 control subjects without the disorder. The measurements were conducted with high-field magnetic resonance spectroscopy, a technique that involves using a magnetic resonance imaging scanner to examine neurotransmitter activity. The schizophrenic patients were found to have a deficit in GABA of about 10 percent when compared with their non-schizophrenic counterparts.

The second half of the study involved demonstrating the significance of the neurochemical deficit on cognition and behavior. To do this the researchers measured the visual perception of the subjects for whom GABA levels were assessed by showing them a well-known illusion in which the presence of a high-contrast surrounding region inhibits the ability to perceive information in the center of the visual field.

The researchers showed that this surround-suppression illusion had less of an effect on patients with schizophrenia, resulting in a highly unusual situation in which they outperformed healthy subjects when baseline differences in generalized task performance were accounted for. The researchers then found that the lower levels of GABA in patients were responsible for this behavioral abnormality.

"The link between changes in patients' brain chemistry and the cognitive impairments they experience never has been shown before in this way," Carter said. "This work provides tremendous support for targeting the GABA system for treatment of cognitive decline in schizophrenia."

Other study authors include Richard Maddock, Michael Minzenberg, and J. Daniel Ragland of UC Davis, and Ariel Rokem and Michael Silver of the University of California, Berkeley, School of Optometry and Helen Wills Neuroscience Institute.

The study was funded by grants from the National Alliance for Research on Schizophrenia and Depression (NARSAD) and a grant from the National Institute of Health's National Institute of Mental Health.


Story Source:

The above story is based on materials provided by University of California - Davis - Health System. Note: Materials may be edited for content and length.


Cite This Page:

University of California - Davis - Health System. "Link between brain chemical, cognitive decline in schizophrenia demonstrated." ScienceDaily. ScienceDaily, 11 March 2010. <www.sciencedaily.com/releases/2010/03/100310175130.htm>.
University of California - Davis - Health System. (2010, March 11). Link between brain chemical, cognitive decline in schizophrenia demonstrated. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/2010/03/100310175130.htm
University of California - Davis - Health System. "Link between brain chemical, cognitive decline in schizophrenia demonstrated." ScienceDaily. www.sciencedaily.com/releases/2010/03/100310175130.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