Featured Research

from universities, journals, and other organizations

Brain Chemical Shown To Induce Both Desire And Dread

Date:
July 9, 2008
Source:
Society for Neuroscience
Summary:
The chemical dopamine induces both desire and dread, according to new animal research in the Journal of Neuroscience. Although dopamine is well known to motivate animals and people to seek positive rewards, the study indicates that it also can promote negative feelings like fear. The finding may help explain why dopamine dysfunction is implicated not only in drug addiction, which involves excessive desire, but in schizophrenia and some phobias, which involve excessive fear.

The chemical dopamine induces both desire and dread, according to new animal research in the July 9 issue of The Journal of Neuroscience. Although dopamine is well known to motivate animals and people to seek positive rewards, the study indicates that it also can promote negative feelings like fear. The finding may help explain why dopamine dysfunction is implicated not only in drug addiction, which involves excessive desire, but in schizophrenia and some phobias, which involve excessive fear.

"This study changes our thinking about what dopamine does," said Howard Fields, MD, PhD, of the University of California, San Francisco, an expert unaffiliated with the study. "There is a huge body of evidence out there to support the idea that dopamine mediates positive effects, like reward, happiness, and pleasure. This study says, it does do that, but it can also promote negative behaviors through actions in an adjacent brain area," Fields said.

Kent Berridge, PhD, and his colleagues at the University of Michigan, identified dopamine's dual effect on the nucleus accumbens, a brain region that motivates people and animals to seek out pleasurable rewards like food, sex, or drugs, but is also involved in fear. They found that inhibiting dopamine's normal function prevented the nucleus accumbens neurons from inducing both rewarding and fearful behaviors, suggesting that dopamine is important in both.

In previous research, Berridge and colleagues showed that a distance of only a few millimeters separated desire and dread functions in the nucleus accumbens (which is only about 5 millimeters long in humans). Because dopamine is an important neurotransmitter in this brain structure, the researchers investigated its role in generating these functions in the current study.

When dopamine was allowed to act normally, injection of a chemical to model normal signaling in the front of the nucleus accumbens caused rats to eat nearly three times as much as they normally do. In contrast, injection of the chemical in the back of the nucleus accumbens caused rats to display fearful behavior normally shown in response to a predator.

"It has always been assumed that discrete neurotransmitters might separate fear from desire, but this report shows that transmitters such as dopamine play a constant role and that the anatomy is providing for emotional discretion," said Peter Kalivas, PhD, at the Medical University of South Carolina, who was unaffiliated with the study.

Berridge speculates that disruption of dopamine neurotransmission in one region of the nucleus accumbens may be a mechanism for pathological excesses of fear in disorders such as schizophrenia, whereas disruptions in dopamine neurotransmission in an adjacent region may be a mechanism for excessive reward-seeking in conditions like addiction.

The research was supported by the National Institute of Mental Health and the National Institute on Drug Abuse.


Story Source:

The above story is based on materials provided by Society for Neuroscience. Note: Materials may be edited for content and length.


Cite This Page:

Society for Neuroscience. "Brain Chemical Shown To Induce Both Desire And Dread." ScienceDaily. ScienceDaily, 9 July 2008. <www.sciencedaily.com/releases/2008/07/080708173226.htm>.
Society for Neuroscience. (2008, July 9). Brain Chemical Shown To Induce Both Desire And Dread. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2008/07/080708173226.htm
Society for Neuroscience. "Brain Chemical Shown To Induce Both Desire And Dread." ScienceDaily. www.sciencedaily.com/releases/2008/07/080708173226.htm (accessed July 24, 2014).

Share This




More Mind & Brain News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Do Obese Women Have 'Food Learning Impairment'?

Do Obese Women Have 'Food Learning Impairment'?

Newsy (July 18, 2014) Yale researchers tested 135 men and women, and it was only obese women who were deemed to have "impaired associative learning." 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:
from the past week

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