New research might help people suffering from post-traumatic stress disorder

August 1, 2011 in Medical research

The discovery of a mechanism in the brain explains for the first time why people make particularly strong, long-lasting memories of stressful events in their lives and could help sufferers of post-traumatic stress disorder.

The study, carried out by researchers from the University of Bristol's Henry Wellcome Laboratories for Integrative Neuroscience & Endocrinology (HW-LINE) in the School of Clinical Sciences, and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), is published online this week in the Proceedings of the National Academy of Sciences (PNAS).

The research found that stress hormones directly stimulate biochemical processes in neurons that play a role in learning and memory. The way these hormones stimulate these signalling and epigenetic processes in neurons is completely new and has never been shown before.

In the healthy brain these processes operate smoothly and help people to cope with and learn from stressful events in their lives. In vulnerable people or in strongly traumatized people (victims of rape or war), these processes may be disturbed and may result in the formation of highly traumatic memories such as those seen in patients suffering from post-traumatic stress disorder (PTSD). The discovery may lead to new ways to develop drugs to help these patients and to prevent PTSD in trauma victims.

Professor Johannes Reul, Professorial Research Fellow in Neuroscience at HW-LINE, said: "Making memories of events in our lives is of critical importance in order to cope properly with new situations and challenges in the future. This is of particular importance for emotional and traumatic life events. Our newly discovered mechanism should be regarded as an adaptive mechanism. We believe this mechanism could be disturbed in stress-related psychiatric disorders such as depression and anxiety.

"The new findings may be of particular significance for patients suffering from post-traumatic (PTSD) as these patients are pained by pathological memories of an endured trauma (rape or war situations). We hope our discovery may help to generate a new class of drugs to help these patients."

The researchers found that stress-induced glucocorticoid hormones enhance memory formation through a direct, physical interaction of glucocorticoid-binding receptors ("glucocorticoid receptor") with a particular intracellular signalling pathway in a specific population of neurons of the hippocampus. This signalling pathway, the so-called ERK MAPK pathway, is known to be strongly involved in learning and memory processes but it was not known that it could interact with glucocorticoid receptors and that this would lead to an enhancement of memory formation.

This type of interaction has never been described before. The interaction has a major impact as the stimulated signalling cascade results in augmented epigenetic mechanisms in the nucleus of the affected neurons leading to enhanced expression of certain gene products. The induced gene products are known to evoke structural and functional changes in neurons allowing them to strengthen their role in the memory circuits of the brain.

It is well known that people make very strong memories of stressful, emotionally disturbing events in their lives. These so-called episodic memories are memories of the place (e.g. room, office) or surroundings where the event happened, how we felt at the time (mood), and the time of the day at which it happened. These kind of memories can last a lifetime.

The consolidation of such memories is taking place in a specific limbic brain region called the hippocampus – part of the involved in memory and learning. Hormones secreted during stress like the glucocorticoid hormone cortisol (in rodents, corticosterone) act on the hippocampus to enhance the consolidation of these memories. However, until now it has been unknown how these hormones act on the hippocampus to enhance the formation of emotional event-related memories.

Provided by University of Bristol search and more info website

not rated yet  

Rank not rated yet
Related Stories
Relevant PhysicsForums posts
  • A question about drug tolerance
    createdMay 23, 2012
  • Poor nutrition leading to overeating?
    createdMay 23, 2012
  • Math and dyslexia?
    createdMay 21, 2012
  • portable metabolism meter?
    createdMay 21, 2012
  • Rare medical conditions on 20/20 tonight
    createdMay 18, 2012
  • "Good" Cholesterol in Doubt
    createdMay 17, 2012
  • More from Physics Forums - Medical Sciences

More news stories

Implantable pain disk may help those with cancer

An estimated 3.5 million cancer patients around the globe are in severe pain from their disease, but many get no relief.

Medical research created 13 hours ago | popularity not rated yet | comments 0 | with audio podcast

Energy levels link sleep control mechanisms

Sleep, or lack of it, can determine level of cognitive performance which is linked with accidents as well as increased risk of serious health problems. Links between cell energy levels, gene transcription ...

Medical research created 15 hours ago | popularity not rated yet | comments 0

Researchers identify key brain cell in antidepressant action

(Medical Xpress) -- Antidepressant medications such as Prozac have helped improve mood and lessen anxiety in millions of people with major depression. But scientists know surprisingly little about how these drugs work.

Medical research created 16 hours ago | popularity 4 / 5 (1) | comments 0 | with audio podcast

Rockefeller scientists pioneer new method to determine mechanisms of drug action

(Medical Xpress) -- Knowing that a drug works is great. Knowing how it works is a luxury. And until now, determining a drug’s mechanism of action has been a tedious and difficult process for scientists.

Medical research created 16 hours ago | popularity not rated yet | comments 0 | with audio podcast

Like curry? New biological role identified for compound used in ancient medicine

Scientists have just identified a new reason why some curry dishes, made with spices humans have used for thousands of years, might be good for you.

Medical research created 23 hours ago | popularity 4.3 / 5 (9) | comments 2 | with audio podcast


Of mice and mental models: Neuroscientific implications of risk-optimized behavior in the mouse

(Medical Xpress) -- Regardless of an organism’s biological complexity, every encephalized animal continuously makes under-informed behavioral choices that can have serious consequences. Despite its ubiquity, ...

Tongue analysis software uses ancient Chinese medicine to warn of disease

For 5,000 years, the Chinese have used a system of medicine based on the flow and balance of positive and negative energies in the body. In this system, the appearance of the tongue is one of the measures used to classify ...

Cancer may require simpler genetic mutations than previously thought

Chromosomal deletions in DNA often involve just one of two gene copies inherited from either parent. But scientists haven't known how a deletion in one gene from one parent, called a "hemizygous" deletion, can contribute ...

Inherited DNA change explains overactive leukemia gene

A small inherited change in DNA is largely responsible for overactivating a gene linked to poor treatment response in people with acute leukemia.

Skp2 activates cancer-promoting, glucose-processing Akt

HER2 and its epidermal growth factor receptor cousins mobilize a specialized protein to activate a major player in cancer development and sugar metabolism, scientists report in the May 25 issue of Cell.

Early physical therapist treatment associated with reduced risk of healthcare utilization and reduced overall healthcare

A new study published in Spine shows that early treatment by a physical therapist for low back pain (LBP), as compared to delayed treatment, was associated with reduced risk of subsequent healthcare utilization and lower ...