Study Shows That The Vicious Stress Loop Is Reversible
The New York Times by NATALIE ANGIER
August 18, 2009
Reporting earlier this summer in the journal Science, Nuno Sousa of the Life and Health Sciences Research Institute at the University of Minho in Portugal and his colleagues described experiments in which chronically stressed rats lost their elastic rat cunning and instead fell back on familiar routines and rote responses, like compulsively pressing a bar for food pellets they had no intention of eating.
Moreover, the rats’ behavioral perturbations were reflected by a pair of complementary changes in their underlying neural circuitry. On the one hand, regions of the brain associated with executive decision-making and goal-directed behaviors had shriveled, while, conversely, brain sectors linked to habit formation had bloomed.
In other words, the rodents were now cognitively predisposed to keep doing the same things over and over, to run laps in the same dead-ended rat race rather than seek a pipeline to greener sewers. Happily, the stress-induced changes in behavior and brain appear to be reversible. To rattle the rats to the point where their stress response remained demonstrably hyperactive, the researchers exposed the animals to four weeks of varying stressors: moderate electric shocks, being encaged with dominant rats, prolonged dunks in water. Those chronically stressed animals were then compared with non-stressed peers. The stressed rats had no trouble learning a task like pressing a bar to get a food pellet or a squirt of sugar water, but they had difficulty deciding when to stop pressing the bar, as normal rats easily did.
But with only four weeks’ vacation in a supportive setting free of bullies and Tasers, the formerly stressed rats looked just like the controls, able to innovate, discriminate and lay off the bar. Atrophied synaptic connections in the decisive regions of the prefrontal cortex resprouted, while the overgrown dendritic vines of the habit-prone sensorimotor striatum retreated.
Recent Postings Of Other Breakthroughs
-
Oxford Psychologists Suggest that the Computer Game, Tetris, May Reduce a Soldier's Flashbacks
-
Magnetic Impulses Can Help People Learn a Skill Better and Faster
-
Can Positive Thoughts Help Heal Us. Can They Heal Another Person?
-
Outgoing and relaxed people are less likely to develop dementia
-
Finding Happiness: You Can Cajole Your Brain To Lean To The Positive
-
Going For Your Personal Best: Relaxed Is A Good Way To Start
"... executive decision-making and goal-directed behaviors had shriveled, while, conversely, brain sectors linked to habit formation had bloomed."
PO BOX 49 • Oakville CA, 94562 • 866.448.1001 • info@mysticcool.com
© Copyright 2006–2008 ProAttitude, Inc. All Rights Reserved.