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

ScienceDaily (Aug. 2, 2011) — 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 stressful events 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 stress disorder (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 brain 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.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Bristol.

Journal Reference:

María Gutièrrez-Mecinas, Alexandra F. Trollope, Andrew Collins, Hazel Morfett, Shirley A. Hesketh, Flavie Kersanté, and Johannes M. H. M. Reul. Long-lasting behavioral responses to stress involve a direct interaction of glucocorticoid receptors with ERK1/2–MSK1–Elk-1 signaling. Proceedings of the National Academy of Sciences, August 1, 2011 DOI: 10.1073/pnas.1104383108

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here sciencedaily.com

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

ScienceDaily (Aug. 2, 2011) — 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 stressful events 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 stress disorder (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 brain 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.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Bristol.

Journal Reference:

María Gutièrrez-Mecinas, Alexandra F. Trollope, Andrew Collins, Hazel Morfett, Shirley A. Hesketh, Flavie Kersanté, and Johannes M. H. M. Reul. Long-lasting behavioral responses to stress involve a direct interaction of glucocorticoid receptors with ERK1/2–MSK1–Elk-1 signaling. Proceedings of the National Academy of Sciences, August 1, 2011 DOI: 10.1073/pnas.1104383108

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here sciencedaily.com

'Mirroring' might reflect badly on you

ScienceDaily (July 28, 2011) — Imitation may be the sincerest form of flattery, but clueless copycatting comes at a cost. As anyone who has been subjected to the mocking playground game knows, parroting can be annoying. Yet gentle mimicry can act as a kind of "social glue" in human relationships. It fosters rapport and trust. It signals cohesion. Two people who like each other will often unconsciously mirror each other's mannerisms in subtle ways -- leaning forward in close synchrony, for example -- and that strengthens their bond.

The benefits of body-language mimicry have been confirmed by numerous psychological studies. And in popular culture, mirroring is frequently urged on people as a strategy -- for flirting or having a successful date, for closing a sale or acing a job interview. But new research suggests that mirroring may not always lead to positive social outcomes. In fact, sometimes the smarter thing to do is to refrain.

In a study to be published in a forthcoming issue of Psychological Science, Piotr Winkielman and Liam Kavanagh of the psychology department at the University of California, San Diego, along with philosophers Christopher Suhler and Patricia Churchland, also of UC San Diego, note that in real-life situations there are often observers to the mirroring that takes place between two people. This led them to wonder whether mimicry sometimes comes at a reputational cost. Are there cases in which an observer might actually think less of a person for mirroring the behavior of another?

Results of three experiments suggest that mimicry is more nuanced than previously thought and not, the authors write, "uniformly beneficial to the mimicker."

"Mimicry is a crucial part of social intelligence," said Winkielman, UC San Diego professor of psychology. "But it is not enough to simply know how to mimic. It's also important to know when and when not to. The success of mirroring depends on mirroring the right people at the right time for the right reasons. Sometimes the socially intelligent thing to do is not to imitate."

Participants in the study were asked to watch several staged and videotaped interviews. Some saw videos in which the interviewer was cordial and others saw videos in which the (same) interviewer was unfriendly. The people being interviewed in the videos either mirrored the interviewer's simple mannerisms, such as chin-touching or leg-crossing, or they did not. After watching each video, participants evaluated the interviewee on general competence, trustworthiness and likability.

Despite the fact that the participants were not instructed to watch for mimicry and reported no awareness of it, it still influenced their evaluations: Interviewees who mimicked the unfriendly interlocutor were judged to be less competent than those who didn't. That is to say, in the eyes of the outside observers, the imitators of the undesirable model incurred reputational costs -- their unconsciously observed mirroring registered as a kind of error.

In a second corollary experiment, participants were exposed to the same videos but with the interviewer obscured. In other words, they couldn't see any evidence of mimicry, and the results support the researchers' hypothesis: It is not merely interacting with negatively perceived people that has a social cost; you pay a price for aligning with them through body language.

Interestingly, an additional experiment showed that the reputational cost of mimicking an unfriendly interviewer disappeared when participants read positive information about that interviewer -- i.e., that he was engaged in humanitarian work -- before watching the video. "It's almost as though mimicry of a condescending interviewer was forgiven when he was judged to be good at heart," Winkielman said.

Our social lives are incredibly complex, said Winkielman, and in order to build or maintain relationships we have to keep in mind a variety of factors. "It's good to have the capacity to mimic," he said, "but an important part of social intelligence is knowing how to deploy this capacity in a selective, intelligent, context-dependent manner, and understanding, even implicitly, when mirroring can reflect badly on you."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of California - San Diego. The original article was written by Debra Kain.

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here