Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Trust-building hormone short-circuits fear in humans

09.12.2005


A brain chemical recently found to boost trust appears to work by reducing activity and weakening connections in fear-processing circuitry, a brain imaging study at the National Institutes of Health’s (NIH) National Institute of Mental Health (NIMH) has discovered. Scans of the hormone oxytocin’s effect on human brain function reveal that it quells the brain’s fear hub, the amygdala, and its brainstem relay stations in response to fearful stimuli. The work at NIMH and a collaborating site in Germany suggests new approaches to treating diseases thought to involve amygdala dysfunction and social fear, such as social phobia, autism, and possibly schizophrenia, report Andreas Meyer-Lindenberg, M.D., Ph.D., NIMH Genes Cognition and Psychosis Program, and colleagues, in the December 7, 2005 issue of the Journal of Neuroscience.


Functional magnetic resonance imaging data (red) superimposed on structural MRI scans. Frightful faces triggered a dramatic reduction in amygdala activity in subjects who had sniffed oxytocin, suggesting that oxytocin mediates social fear and trust via the amygdala and related circuitry. Source: NIMH Genes, Cognition and Psychosis Program.



"Studies in animals, pioneered by now NIMH director Dr. Thomas Insel, have shown that oxytocin plays a key role in complex emotional and social behaviors, such as attachment, social recognition and aggression," noted NIH Director Elias Zerhouni, M.D.. "Now, for the first time, we can literally see these same mechanisms at work in the human brain."

"The observed changes in the amygdala are exciting as they suggest that a long-acting analogue of oxytocin could have therapeutic value in disorders characterized by social avoidance," added Insel.


Inspired by Swiss scientists who last summer reported [1] that oxytocin increased trust in humans, Meyer-Lindenberg and colleagues quickly mounted a brain imaging study that would explore how this works at the level of brain circuitry. British researchers had earlier linked increased amygdala activity to decreased trustworthiness. [2] Having just discovered decreased amygdala activity in response to social stimuli in people with a rare genetic brain disorder that rendered them overly trusting of others, Meyer-Lindenberg hypothesized that oxytocin boosts trust by suppressing the amygdala and its fear-processing networks.

To test this idea, he asked 15 healthy men to sniff oxytocin or a placebo prior to undergoing a functional magnetic resonance imaging (fMRI) scan, which reveals what parts of the brain that are activated by particular activities. While in the scanner, the men performed tasks known to activate the amygdala – matching angry or fearful faces and threatening scenes.

As expected, the threatening pictures triggered strong activation of the amygdala during the placebo scan, but markedly less activity following oxytocin. The difference was especially pronounced in response to threatening faces, suggesting a pivotal role for oxytocin in regulating social fear. In addition, oxytocin dampened the amygdala’s communication with sites in the upper brainstem that telegraph the fear response. The results mirrored findings in rats [3], reported earlier this year by European scientists.

"Because increased amygdala activation has been associated with social fear in social phobia, genetic risk for anxiety and depression, and possibly with social fear in autism assessed during faces processing, this dual mode of action of oxytocin in humans suggests a potentially powerful treatment approach toward socially relevant fear," suggest the researchers.

People with autism characteristically avert their gaze from faces. A fMRI study [4] reported earlier this year by NIMH grantee Richard Davidson, Ph.D., University of Wisconsin, and colleagues, found over-activation of the amygdala in people with autism when they were looking at faces. Meyer-Lindenberg said future studies may test oxytocin as a treatment for such social anxiety symptoms in children with autism.

"Future research may also examine how oxytocin affects the amygdala in women, the mode of action of related hormones such as vasopressin, and how genetic variants in these hormones and their receptors affect brain function," he added.

Also participating in the research were: Peter Kirsch, Christin Esslinger, Daniela Mier, Stefanie Lis, Harald Gruppe, Bernd Gallhofer, Justus-Liebig University, Giessen, Germany; Qiang Chen, Sarina Siddhanti, Venkata Mattay, NIMH Genes Cognition and Psychosis Program.

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

More articles from Health and Medicine:

nachricht Finnish research group discovers a new immune system regulator
23.02.2018 | University of Turku

nachricht Minimising risks of transplants
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>