Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Maturing brain flips function of amygdala in regulating stress hormones

21.08.2014

In contrast to evidence that the amygdala stimulates stress responses in adults, researchers at Yerkes National Primate Research Center, Emory University have found that the amygdala has an inhibitory effect on stress hormones during the early development of nonhuman primates. The results are published this week in Journal of Neuroscience.

The amygdala is a region of the brain known to be important for responses to threatening situations and learning about threats. Alterations in the amygdala have been reported in psychiatric disorders such as depression, anxiety disorders like PTSD, schizophrenia and autism spectrum disorder. However, much of what is known about the amygdala comes from research on adults.


The amygdala is a region of the brain known to be important for responses to threats and learning about threats. Its function regulating stress hormones undergoes significant changes as the brain matures, Yerkes research suggests.

Image courtesy of NIMH

"Our findings fit into an emerging theme in neuroscience research: that during childhood, there is a switch in amygdala function and connectivity with other brain regions, particularly the prefrontal cortex," says Mar Sanchez, PhD, neuroscience researcher at Yerkes and associate professor of psychiatry and behavioral sciences at Emory University School of Medicine. The first author of the paper is postdoctoral fellow Jessica Raper, PhD.

The findings are part of a larger longitudinal study at Yerkes National Primate Research Center, examining how amygdala damage within the first month of life affects the development of social and emotional behaviors and neuroendocrine systems in rhesus monkeys from infancy through adulthood. The laboratories of Sanchez and Yerkes researchers Jocelyne Bachevalier, PhD and Kim Wallen, PhD are collaborating on this project.

Previous investigations at Yerkes found that as infants, monkeys with amygdala damage showed higher levels of the stress hormone cortisol. This surprising result contrasted with previous research on adults, which showed that amygdala damage results in lower levels of cortisol.

The team hypothesized that damage to the amygdala generated changes in the HPA axis: a network of endocrine interactions between the hypothalamus within the brain, the pituitary and the adrenal glands, critical for reactions to stress.

"We wanted to examine whether the alterations in stress hormones seen during infancy persisted, and what brain changes were responsible for them," Sanchez says. "In studies of adults, the amygdala and its connections are fully formed at the time of the manipulation, but here neither the amygdala or its connections were fully matured when the damage occurred."

In the current paper, the authors demonstrated that in contrast with adult animals with amygdala damage, juvenile monkeys with early amygdala damage had increased levels of cortisol in the blood, compared to controls. In their cerebrospinal fluid, they also had elevated levels of corticotropin releasing factor (CRF), the neuropeptide that initiates the stress response in the brain. Elevated CRF and cortisol are linked to anxiety and emotional dysregulation in patients with mood disorders.

Despite the increased levels of stress hormones, monkeys with early amygdala damage exhibit a blunted emotional reactivity to threats, including decreased fear and aggression, and reduced anxiety in response to stress. Still, monkeys with neonatal amygdala damage remain competent in interacting with others in their large social groups. These findings are consistent with reports of human patients with damage to the amygdala, Raper says.

"We speculate that the rich social environment provided to the monkeys promotes compensatory mechanisms in cortical regions implicated in the regulation of social behavior," she says. "But neonatal amygdala damage seems more detrimental for the development of stress neuroendocrine circuits in other areas of the brain."

The investigators plan to follow the animals into adulthood to investigate the long-term effects of early amygdala damage on stress hormones, behavior and physiological systems possibly affected by chronically high cortisol levels, such as immune, growth and reproductive functions.

The research was supported by the National Institutes of Mental Health (MH050268, MH732525), the National Science Foundation (Center for Behavioral Neuroscience: IBN 9876754) and the Office of Research Infrastructure Programs (Primate centers: P51OD11132 – formerly NCRR P51RR000165).

Lisa Newbern | Eurek Alert!
Further information:
http://news.emory.edu/stories/2014/08/amygdala_stress_hormones_yerkes/

Further reports about: CRF Health Infrastructure Medicine Neuroscience damage disorders environment function hormones

More articles from Life Sciences:

nachricht New mechanisms uncovered explaining frost tolerance in plants
26.09.2016 | Technische Universität München

nachricht Chains of nanogold – forged with atomic precision
23.09.2016 | Suomen Akatemia (Academy of Finland)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Stronger turbine blades with molybdenum silicides

26.09.2016 | Materials Sciences

Scientists Find Twisting 3-D Raceway for Electrons in Nanoscale Crystal Slices

26.09.2016 | Materials Sciences

Lowering the Heat Makes New Materials Possible While Saving Energy

26.09.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>