Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stress hormone elevation is associated with working memory deficits in aging

18.06.2014

Animal study suggests that stress may accelerate age-related changes in the brain

 A new study published in the June 18 issue of The Journal of Neuroscience adds to a body of evidence suggesting stress may accelerate cognitive decline later in life. The study found that aged rats with high levels of the stress hormone corticosterone showed structural changes in the brain and short-term memory deficits.

While most people will experience some cognitive decline as they get older, the extent of these changes and how rapidly they progress varies greatly from one person to the next. Scientists are interested in understanding the factors that contribute to these differences. Research suggests that how the body responds to stress may be one of the factors influencing how the brain ages. Multiple animal studies have linked high levels of the stress hormone corticosterone (similar to the human stress hormone cortisol) with age-related structural and functional decline in the hippocampus, a region that plays a key role in long-term memory.

Jason J. Radley of the University of Iowa wanted to know whether exposure to high levels of corticosterone is associated with other changes in the brain and memory deficits. In the current study, he and others measured the amount of the stress hormone in the blood of young and old rats and examined cells in the prefrontal cortex, a region of the brain involved in short-term memory. The researchers found that older animals with high levels of the stress hormone had fewer connections between prefrontal cortex cells than the older animals with lower levels of the hormone. In contrast, prefrontal cortex cells appeared similar in younger animals regardless of stress hormone levels.

"Older animals with higher levels of stress hormones in their blood have 'older' frontal cortexes than animals with less stress hormones," explained Stanford University professor Robert Sapolsky, PhD, an expert on the damaging effects of long-term stress who was not involved with this study. "Thus, stress may act as a pacemaker of aging in this key brain region."

Older rats with higher levels of stress hormone displayed a 20 percent reduction in the density of dendritic spines (the small protrusions on neurons that come into close contact with other cells to form synapses, the connections between cells) relative to age-matched rats with less stress hormone.

The researchers also compared how the young and old rats performed on a simple working memory task, where the animals had to remember which arm of a two-arm maze contained a food reward following varying periods of delay. Older animals with higher levels of corticosterone made more errors when attempting to predict the location of the reward than age-matched animals with less of the stress hormone after a brief period of delay.

"These findings are not meant to indicate that high stress hormones are the only factor in determining the decline of mental abilities during aging," Radley cautioned. "Nonetheless, this study suggests that the effects of these stress hormones on the brain may be much more widespread than we previously thought."

###

This research was funded by the National Institute of Mental Health.

The Journal of Neuroscience is published by the Society for Neuroscience, an organization of nearly 40,000 basic scientists and clinicians who study the brain and nervous system. Radley can be reached at jason-radley@uiowa.edu. More information on aging, stress, and memory can be found on BrainFacts.org.

Emily Ortman | Eurek Alert!

Further reports about: Neuroscience animals corticosterone deficits hormones levels rats

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

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

23.09.2016 | Event News

 
Latest News

The first genome of a coral reef fish

29.09.2016 | Life Sciences

Gentle sensors for diagnosing brain disorders

29.09.2016 | Medical Engineering

Swiss space research reaches for the sky

29.09.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>