Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Emotion-regulating protein lacking in panic disorder

22.01.2004


Three brain areas of panic disorder patients are lacking in a key component of a chemical messenger system that regulates emotion, researchers at the NIH’s National Institute of Mental Health (NIMH) have discovered. Brain scans revealed that a type of serotonin receptor is reduced by nearly a third in three structures straddling the center of the brain. The finding is the first in living humans to show that the receptor, which is pivotal to the action of widely prescribed anti-anxiety medications, may be abnormal in the disorder, and may help to explain how genes might influence vulnerability. Drs. Alexander Neumeister and Wayne Drevets, NIMH Mood and Anxiety Disorders Program, and colleagues, report on their findings in the January 21, 2004 Journal of Neuroscience.



Each year, panic attacks strike about 2.4 million American adults "out of the blue," with feelings of intense fear and physical symptoms sometimes confused with a heart attack. Unchecked, the disorder often sets in motion a debilitating psychological sequel syndrome of agoraphobia, avoiding public places. Panic disorder runs in families and researchers have long suspected that it has a genetic component. The new finding, combined with evidence from recent animal studies, suggests that genes might increase risk for the disorder by coding for decreased expression of the receptors, say the researchers.

NIMH grantee Dr. Rene Hen, Columbia University, and colleagues, reported in 2002 that a strain of gene "knockout" mice, engineered to lack the receptor during a critical period in early development, exhibit anxiety traits in adulthood, such as a reluctance to begin eating in an unfamiliar environment. More recent experiments with the knockout mice show that a popular SSRI (serotonin selective reuptake inhibitor) drug produces its anti-anxiety effects by stimulating the formation of new neurons in the hippocampus via the serotonin 5-HT1A receptor.


In the current study, Neumeister and Drevets used PET scans (positron emission tomography) to visualize 5-HT1A receptors in brain areas of interest in 16 panic disorder patients – seven of whom also suffered from major depression – and 15 matched healthy controls. A new radioactive tracer (FCWAY), developed by NIH Clinical Center PET scan scientists, binds to the receptors, revealing their locations and a numerical count by brain region. Subjects also underwent structural MRI (magnetic resonance imaging) scans, which were overlaid with their PET scan data to precisely match it with brain structures.

In the panic disorder patients, including those who also had depression, receptors were reduced by an average of nearly a third in the anterior cingulate in the front middle part of the brain, the posterior cingulate, in the rear middle part of the brain, and in the raphe, in the midbrain (See images below.). Previous functional brain imaging studies have implicated both the anterior and posterior cingulate in the regulation of anxiety. Stimulation of 5-HT1A receptors in the raphe regulates serotonin synthesis and release. In an earlier PET study of depressed patients, using a different tracer, Drevets and colleagues found less dramatic reductions of the receptor in the anterior and posterior cingulate, but a 41 percent reduction in the raphe. These findings add to evidence for overlap between depression and anxiety disorders.

Although animal experiments have shown that cortisol secretion triggered by repeated stress reduces expression of the gene that codes for the 5-HT1A receptor, such stress hormone elevations are usually not found in panic disorder. Noting the recent discovery of a variant of the 5-HT1A receptor gene linked to major depression and suicide, the researchers suggest that reduced expression of the receptor "may be a source of vulnerability in humans, and that abnormal function of these receptors appears to specifically impact the cortical circuitry involved in the regulation of anxiety."


Other researchers who participated in the study are Drs. Earle Bain, Allison Nugent, Omer Bonne, David Luckenbaugh, Dennis Charney, NIMH; Richard Carson, William Eckelman, Peter Herscovitch, Warren G. Magnuson Clinical Center.

The National Institute of Mental Health (NIMH) and the Warren G. Magnuson Clinical Center are parts of the National Institutes of Health (NIH), the Federal Government’s primary agency for biomedical and behavioral research. NIH is a component of the U.S. Department of Health and Human Services.

Jules Asher | EurekAlert!
Further information:
http://www.nimh.nih.gov/

More articles from Health and Medicine:

nachricht A step closer to cancer precision medicine
15.11.2019 | University of Helsinki

nachricht Can 'smart toilets' be the next health data wellspring?
14.11.2019 | Morgridge Institute for Research

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Atoms don't like jumping rope

Nanooptical traps are a promising building block for quantum technologies. Austrian and German scientists have now removed an important obstacle to their practical use. They were able to show that a special form of mechanical vibration heats trapped particles in a very short time and knocks them out of the trap.

By controlling individual atoms, quantum properties can be investigated and made usable for technological applications. For about ten years, physicists have...

Im Focus: Images from NJIT's big bear solar observatory peel away layers of a stellar mystery

An international team of scientists, including three researchers from New Jersey Institute of Technology (NJIT), has shed new light on one of the central mysteries of solar physics: how energy from the Sun is transferred to the star's upper atmosphere, heating it to 1 million degrees Fahrenheit and higher in some regions, temperatures that are vastly hotter than the Sun's surface.

With new images from NJIT's Big Bear Solar Observatory (BBSO), the researchers have revealed in groundbreaking, granular detail what appears to be a likely...

Im Focus: New opportunities in additive manufacturing presented

Fraunhofer IFAM Dresden demonstrates manufacturing of copper components

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...

Im Focus: New Pitt research finds carbon nanotubes show a love/hate relationship with water

Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.

New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...

Im Focus: Magnets for the second dimension

If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.

Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

 
Latest News

How LISA pathfinder detected dozens of 'comet crumbs'

19.11.2019 | Physics and Astronomy

Trash talk hurts, even when it comes from a robot

19.11.2019 | Social Sciences

The evolution and genomic basis of beetle diversity

19.11.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>