Stress really does mess with your mind. A new study has found that chronic stress can create many of the brain changes associated with mood disorders by blocking a gene called neuritin, and that boosting the gene's activity can protect the brain from those disorders. The results provide new insight into the mechanisms behind depression, anxiety, and bipolar disorder, and could offer researchers a novel target for drugs to treat those conditions.
Research has shown that mood disorders take a toll on patients' brains as well as on their lives. Postmortem studies and brain scans have revealed that the hippocampus (the brain's memory center) can shrink and atrophy in people with a history of depression and other mood disorders. People who live with mood disorders are also known to have low levels of brain-derived neurotrophic factor (BDNF), a growth factor that keeps neurons healthy. They also have low activity in the neuritin gene, which codes for a protein of the same name that may protect the brain's plasticity: its ability to reorganize and change in response to new experiences.
Ronald Duman, a neurobiologist at Yale University, and colleagues wondered if the poorly understood neuritin might play an important_and heretofore overlooked_role in depression and other mood disorders. They induced depression in a group of rats by subjecting them to chronic, unpredictable stress. Depriving them of food and play, isolating them, and switching around their day/night cycles for about 3 weeks left the rats with little interest in feeding or enjoying a sweetened drink. The rats also gave up and became immobile instead of swimming when placed in a tub of water another measure of rodent depression.
All of the depressed rats showed low levels of neuritin gene activity, and all improved when treated with antidepressants. But boosting their neuritin protein levels helped just as much, the researchers report online Monday in the Proceedings of the National Academy of Sciences. The team found that increasing production of neuritin by injecting the rats with a virus that triggered the gene's expression protected the rats from brain cell atrophy and other structural brain changes seen in mood disorders, even when the rats were exposed to chronic stress.
"Neuritin produced a response that looked exactly like an antidepressant," says Duman. "I was surprised to find this molecule was sufficient, by itself, to block the effects of stress and depression."
To further confirm neuritin's role, the researchers blocked the activity of the gene in another group of rats without stressing them out. The rodents exhibited the same symptoms of depression as stressed rats.
The results add to a growing body of evidence that implicates stress in the development and progression of mood disorders, and it suggests that compounds mimicking neuritin's action are another way to treat them, says John Neumaier, a psychiatrist and neuroscientist at the University of Washington, Seattle, who was not involved in the work. "This is a great study, one that uncovers another layer in the biology of depression and antidepressants," he says. "It opens up a new therapeutic target."
That target is much-needed, adds neurobiologist Scott Russo of the Mount Sinai School of Medicine in New York City. Only about 30 percent of people with mood disorders achieve full remission on existing antidepressants, Russo says, "and there's been a fundamental failure to turn new discoveries into new drugs we can use in clinical practice . . . if someone is willing to take the risk and the financial responsibility, neuritin could be a good approach."
Features
Why stress makes you miserable
- Features
-
-
Children help garden, community grow
This is the story of a garden, but it is also the story of how two needs were met in a small backyard in Valdosta. How a physically challenged couple has come to love the weekly visits of nearly two dozen children and how those youngsters have learned a sense of community by, what Jane Teasley calls, “planting it forward.” It is a story of not only how a garden grows but how friendships and a sense of community can grow.
-
Movie worthy of ‘Internship’
Movie Reviews: The Internship, The Purge
-
A Superman for all seasons
Superman seems a character who is needed every generation or so.
He was created in the late 1930s during a period when dictatorships were spreading across Europe. Superman came into being during the end of the Great Depression, at a time when the world was about to be steeped in a terrible global conflict. -
New mission: LAMP focuses on homeless
Call it a rebranding or a new mission, Lowndes Associated Ministries to People has changed its focus.
-
Books: Inferno by Dan Brown
Dan Brown’s “Inferno” is one of those books that you either have already bought, already read, plan to buy or plan to read, or simply have no interest in it at all, and no review will likely keep anyone from reading it or encourage anyone not already interested to open it.
-
An after-thought for ‘After Earth’
Movie Reviews: "After Earth," "Now You See Me"
-
All in the Family
Paint may well be in their blood. That and talent. Before going any further, it may help to name the players and getting their relationships straight. Think of Esther Arthur as the grandmother then there’s her daughter, D. Arthur McBride. Then, there are McBride’s two sons, Thomas M. Thomson and Ron Thomson, who are, of course, Arthur’s grandsons. Each is an artist in her and his own right. Each impressive in their specific styles and skill sets.
-
Youngsters bring ‘Sound of Music’ von Trapp children to life
From the moment they march onto the stage and stand at attention, the von Trapp children performers have the audience’s support.
-
Creedence Clearwater Revisted coming to Wild Adventures
The question must be asked, but you know it must be the last question asked. Interviewing Stu Cook, bass player for Creedence Clearwater Revisited playing this weekend at Wild Adventures, and original member of Creedence Clearwater Revival, a reporter must ask about the split among band members.
-
Artist Jim Touchton readies a Grand show
Energy still consumes artist Jim Touchton’s canvases. Looking at paintings planned for his “A Grand Affair” exhibit at Artists on Ashley this week, Touchton dwells less on subjects than in the past while increasing his dynamic approach to painted colors and brushstroke rhythms.
- More Features Headlines
-
