RESEARCH HINTS AT WHY STRESS IS MORE DEVASTATING FOR SOME
From the FMS Global News Desk of Jeanne Hambleton Released: 3-Sep-2014 Source Newsroom: Rockefeller University
Newswise — Some people take stress in stride; others are done in by it. New research at Rockefeller University has identified the molecular mechanisms of this so-called stress gap in mice with very similar genetic backgrounds — a finding that could lead researchers to better understand the development of psychiatric disorders such as anxiety and depression.
“Like people, each animal has unique experiences as it goes through its life. And we suspect that these life experiences can alter the expression of genes, and as a result, affect an animal’s susceptibility to stress,” says senior author Bruce McEwen, Alfred E. Mirsky Professor and head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology.
“We have taken an important step toward explaining the molecular origins of this stress gap by showing that inbred mice react differently to stress, with some developing behaviors that resemble anxiety and depression, and others remaining resilient.”
The results, published September 2 in Molecular Psychiatry, point toward potential new markers to aid the diagnosis of stress-related disorders, such as anxiety and depression, and a promising route to the development of new treatments for these devastating disorders.
In experiments, researchers stressed the mice by exposing them to daily, unpredictable bouts of cage tilting, altered dark-light cycles, confinement in tight spaces and other conditions mice dislike with the goal of reproducing the sort of stressful experiences thought to be a primary cause of depression in humans. Afterward, in tests to see if the mice displayed the rodent equivalent of anxiety and depression symptoms, they found about 40 per cent showed high levels of behaviours that included a preference for a dark compartment over a brightly lit one, or a loss of interest in sugar water. The remaining 60 per cent recovered well from the stress. This distinction between the susceptible mice and the resilient ones was so fundamental that it emerged even before the mice were subjected to stress; some unstressed mice showed an anxiety-like preference for a dark compartment over a lighted one.
The researchers found that the highly stress-susceptible mice had less of an important molecule known as mGlu2 in a stress-involved region of the brain known as the hippocampus. The mGlu2 decrease, they determined, resulted from an epigenetic change, which affects the expression of genes, in this case the gene that codes for mGlu2.
“If you think of the genetic code as words in a book, the book must be opened in order for you to read it. These epigenetic changes, which affect histone proteins associated with DNA, effectively close the book, so the code for mGlu2 cannot be read,” says first author Carla Nasca, a postdoc in the lab and a fellow of the American Foundation for Suicide Prevention.
Previously, she and colleagues implicated mGlu2 in depression when they showed that a promising potential treatment known as acetyl carnitine rapidly alleviated depression-like symptoms in rats and mice by reversing these epigenetic changes to mGlu2 and causing its levels to increase.
“Currently, depression is diagnosed only by its symptoms,” Nasca says. “But these results put us on track to discover molecular signatures in humans that may have the potential to serve as markers for certain types of depression. Our work could also lead to a new generation of rapidly acting antidepressants, such as the candidate acetyl carnitine, which would be particularly important to reduce the risk of suicide.”
A reduction in mGlu2 matters because this molecule regulates the neurotransmitter glutamate. While glutamate plays a crucial role relaying messages between neurons as part of many important processes, too much can lead to harmful structural changes in the brain.
“The brain is constantly changing. When stressful experiences lead to anxiety and depressive disorders the brain becomes locked in a state it cannot spontaneously escape,” McEwen says.
“Studies like this one are increasingly focusing on the regulation of glutamate as an underlying mechanism in depression and, we hope, opening promising new avenues for the diagnosis and treatment of this devastating disorder.”
The Hope for Depression Research Foundation and the American Society for Suicide Prevention sponsored this research.
REACTING TO PERSONAL SETBACKS: DO YOU BOUNCE BACK OR GIVE UP?
From the FMS Global News Desk of Jeanne Hambleton Embargoed: 4-Sep-2014 Citations Neuron 10.1016/j.neuron.2014.08.012Source Newsroom: Rutgers University
Newswise — Sometimes when people get upsetting news – such as a failing exam grade or a negative job review – they decide instantly to do better the next time. In other situations that are equally disappointing, the same people may feel inclined to just give up.
How can similar setbacks produce such different reactions? It may come down to how much control we feel we have over what happened, according to new research from Rutgers University-Newark. The study, published in the journal Neuron, also finds that when these setbacks occur, the level of control we perceive may even determine which of two distinct parts of the brain will handle the crisis.
“Think of the student who failed an exam,” says Jamil Bhanji, a postdoctoral fellow at Rutgers and one of the study’s co-authors.
“They might feel they would not have failed if they had studied harder, studied differently – something under their control.” That student, Bhanji says, resolves to try new study habits and work hard toward acing the next exam. Functional magnetic resonance imaging (fMRI) used in the study showed activity in a part of the brain called the ventral striatum – which has been shown to guide goals based on prior experiences.
A different student might have failed the same test, but believes it happened because the questions were unfair or the professor was mean, things that he could not control. The negative emotions produced by this uncontrollable setback may cause the student to drop the course.
Overcoming those negative emotions and refocusing on doing well in the class may require a more complicated thought process. In cases like this, fMRI revealed that activity in the ventromedial prefrontal cortex (vmPFC), a part of the brain that regulates emotions in more flexible ways, is necessary to promote persistence.
Mauricio Delgado, an associate professor of psychology at Rutgers’ Newark College of Arts and Sciences and the study’s other co-author, says people whose jobs include delivering bad news should pay attention to these results, because their actions might influence how the news is received.
“You may deliver the news to the student – no sugar coating, here’s your setback,” says Delgado. “But then you make an offer – ‘would you like to review those study habits with me? I would be happy to do it.’ This puts the student in a situation where they may experience control and be more likely to improve the next time.” This approach, Delgado says, may be far more constructive than curtly delivering a bad grade.
Bhanji says lessons from the study may even guide certain people toward giving up too soon on careers where they could do well. “We wonder why there are fewer women and minorities in the sciences, for example,” he explains.
“Maybe in cases like that it is fair to say there are things we can do to promote reactions to negative feedback that encourage persistence.”
That is not to say everyone should persist. “There are times,” Delgado adds, “when you should not be persistent with your goals. That is where the striatal system in the brain, which can be a source of more habitual responses, may be a detriment. You keep thinking ‘I can do it, I can do it.’ But maybe you should not do it. During these times, interpreting the setback more flexibly, via the vmPFC, may be more helpful.”
As research continues, adds Bhanji, important areas to explore will include “figuring out when it’s worth continuing to keep trying and when it is not.”
PROFESSORS PROVIDE MOST UPDATED INFORMATION ON ASPIRIN IN THE PREVENTION OF A FIRST HEART ATTACK
From the FMS Global News Desk of Jeanne Hambleton Released: 2-Sep-2014 Citations Trends in Cardiovascular Medicine Source : Florida Atlantic University
Newswise — The first researcher in the world to discover that aspirin prevents a first attack, Charles H. Hennekens, M.D., Dr.P.H., the first Sir Richard Doll professor and senior academic advisor to the dean in the Charles E. Schmidt College of Medicine at Florida Atlantic University, has published a comprehensive review in the current issue of the journal Trends in Cardiovascular Medicine.
Hennekens and his coauthor James E. Dalen, M.D., M.P.H., executive director of the Weil Foundation and dean emeritus, University of Arizona College of Medicine, provide the most updated information on aspirin in the prevention of a first heart attack.
Hennekens also presented these findings from the article titled “Aspirin in the Primary Prevention of Cardiovascular Disease: Current Knowledge and Future Research Needs,” on Saturday, Aug. 30 at a “Meet the Experts” lecture at the European Society of Cardiology meetings in Barcelona, Spain. Serving as chair of a symposium on Sunday, Aug. 31, he also delivered a lecture on “Evolving Concepts in Cardiovascular Prevention: Aspirin Then and Now.”
In the article, Hennekens and Dalen emphasize that the evidence in treatment indicates that all patients having a heart attack or who have survived a prior event should be given aspirin. In healthy individuals, however, they state that any decision to prescribe aspirin should be an individual clinical judgment by the healthcare provider that weighs the absolute benefit in reducing the risk of a first heart against the absolute risk of major bleeding.
“The crucial role of therapeutic lifestyle changes and other drugs of life saving benefit such as statins should be considered with aspirin as an adjunct, not alternative,” said Hennekens. “The benefits of statins and aspirin are, at the very least, additive. The more widespread and appropriate use of aspirin in primary prevention is particularly attractive, especially in developing countries where cardiovascular disease is emerging as the leading cause of death.”
Hennekens also notes that aspirin is generally widely available over the counter and is extremely inexpensive. He cautions, however, that more evidence is necessary in intermediate risk subjects before general guidelines should be made.
Among the numerous honors and recognition Hennekens has received include the 2013 Fries Prize for Improving Health for his seminal contributions to the treatment and prevention of cardiovascular disease, the 2013 Presidential Award from his alma mater, Queens College for his distinguished contributions to society, the 2013 honoree as part of FAU’s Charles E. Schmidt College of Medicine from the American Heart Association for reducing deaths from heart attacks and strokes, and the 2014 honoree from the Ochsner Foundation for his seminal research on smoking and disease.
From 1995 to 2005, Science Watch ranked Hennekens as the third most widely cited medical researcher in the world and five of the top 20 were his former trainees and/or fellows. In 2012, Science Heroes ranked Hennekens No. 81 in the history of the world for having saved more than 1.1 million lives.
– FAU –
About Florida Atlantic University:
Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, the University, with an annual economic impact of $6.3 billion, serves more than 30,000 undergraduate and graduate students at sites throughout its six-county service region in southeast Florida. FAU’s world-class teaching and research faculty serves students through 10 colleges: the Dorothy F. Schmidt College of Arts and Letters, the College of Business, the College for Design and Social Inquiry, the College of Education, the College of Engineering and Computer Science, the Graduate College, the Harriet L. Wilkes Honors College, the Charles E. Schmidt College of Medicine, the Christine E. Lynn College of Nursing and the Charles E. Schmidt College of Science. FAU is ranked as a High Research Activity institution by the Carnegie Foundation for the Advancement of Teaching. The University is placing special focus on the rapid development of three signature themes – marine and coastal issues, biotechnology and contemporary societal challenges – which provide opportunities for faculty and students to build upon FAU’s existing strengths in research and scholarship..
Back soon. Jeanne