Stress and the Brain

[Mr Rayon]

How much of an affect can stress have on the brain? To what extent can it cause a decrease in intelligence? When we are at a time where we are feeling stressed or angry our adrenal glands release cortisol. Having cortisol released for long periods of time has been known to damage the hippocampus of the brain making it more difficult to form the type of memories associated with it, and therefore reduce IQ levels. So, my question is how much of an affect can be seen when cortisol is released for a specific period (you can choose how specific, generally the more specific the better)? Does the release of cortisol cause other damage to brain structures? Can this be fixed?

[Monomer]

Maybe these will answer your question:

 

 

General Psychiatry, investigators at Washington University School of Medicine in St. Louis provide the first direct evidence that several days of exposure to cortisol at levels associated with major physical or psychological stresses can have a signifcant negative effect on memory.

 

"We tested memory and other cognitive functions before treatment, after one day of treatment and again after four days, in individuals receiving either a high dose of cortisol, a lower dose or an inactive substance," explained lead author John W. Newcomer, M.D., assistant professor of psychiatry and psychology. "We saw memory impairment only in the individuals treated with the higher dose and only after four days of exposure. The good news is it appears that it would take several days of stresses like major surgery or severe psychological trauma in order for cortisol to produce memory impairment. And after a one-week wash-out period, memory performance returned to the untreated levels."

http://www.scienceblog.com/community/older/1999/E/199904719.html

 

 

Our brains appear to be most vulnerable to the effects of excessive stress in a region called the hippocampus. The hippocampus is a mass of neurons each with multiple branch-like extensions (dendrites and axons) which make connections (synapses) with other neurons all across the brain. Among other things, this region is important in dealing with emotions and consolidating new memories. As with all brain regions, its ability to adapt relies upon being able to alter the branching and connections of its neurons. The hippocampus is also one of the only regions of the brain known to be able to produce new neurons, a process called neurogenesis.

 

Brain Damage

 

Enduring a high stressor for more than 30 minutes to an hour has been shown to negatively impact the hippocampus in various ways. To begin, sustained exposure to higher than normal levels of cortisol results in the pruning back of the number of branches and synaptic connections of hippocampal neurons. By a variety of mechanisms, these conditions also increase the rate of cell death in this region of the brain.

 

As if this wasn’t bad enough, recent research is also demonstrating that sustained increases in glucocorticoid levels also has negative effects, impairing the hippocampus’s ability to create new neurons.

 

Over a period of time, all of this results in the shrinking in size of the hippocampus with associated declines in cognitive function, including the ability to retain new information and adapt to novel situations.

 

Damage Control

 

Fortunately the negative effects of excessive stress can not only be stopped but also reversed once the source (psychological or physical) is removed or sufficiently reduced. Next time we will explore techniques one can use to protect our brains by managing the unavoidable stressors we all face as part of being human.

http://www.sharpbrains.com/blog/2008/02/05/stress-and-neural-wreckage-part-of-the-brain-plasticity-puzzle/

 

 

 

Something else to read:

http://www.sfn.org/index.cfm?pagename=brainBriefings_stressAndTheBrain