Power Up Your Brain by David Perlmutter M. D., Alberto Villoldo Ph.d. Page B
Authors: David Perlmutter M. D., Alberto Villoldo Ph.d.
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and hypothalamus are both located within the limbic brain, and the adrenal glands are located above the kidneys. If the amygdala perceives an imminent threat, the HPA axis, rather than passing the signal along to the neocortex for logical processing, releases stress hormones—cortisol and adrenaline— into the bloodstream. These steroids give us quick energy, increase our heart rate, direct blood away from digestion and other nonemergency body functions, and reroute blood to our extremities and muscles so we can fight or flee. The advantages offered by the rapid response of our HPA axis are clear. Just as primitive man was able to avoid being attacked by an animal during a hunt, we today can quickly move out of the way of an oncoming car or an angry colleague.
In times of danger, this chemical influx is necessary to help us fight or flee, but we can get locked into a state of chronic stress when the adrenal glands don’t receive a signal to stop producing these hormones. Unlike acute stress, which serves a positive purpose, chronic stress is very destructive. In Colonial times the legendary pirates of the Caribbean learned that citizens in a city under siege were more effectively worn down by the sound of cannons firing than by the actual damage done to their town by the cannonballs. This was because the sounds of the guns kept the townspeople in a state of chronic stress, unable to fight or flee, or get a good night’s rest. Long-term exposure to stress has very profound consequences.
THE DETRIMENTAL EFFECTS OF CHRONIC STRESS
Relating this information back to what we have already learned about the evolution of the brain, it’s important to note that the stress hormone cortisol, which is produced in excessive amounts when the HPA axis is locked in a state of chronic stress, increases the damaging effects of free radicals in the neurons of the hippocampus. This causes damage to the mitochondria, which in turn causes even more free radical production. The final act in this tragic play is that the hippocampal neurons themselves perish through the process of apoptosis. And when hippocampal neurons die, learning and creativity become almost impossible. And brain synergy is out of the question. The avoidance of pain overshadows natural curiosity; we hesitate to rock the boat; we hoard needlessly and risk foolishly. We become paralyzed by an inability to discover novel solutions and are unable to think or feel originally anymore. If we remain under acute stress long enough, our adrenals eventually give out and we become drained and exhausted.
In a recent study, Eduardo Dias-Ferreira and his colleagues at the University of Minho in Braga, Portugal, demonstrated that chronically stressed rats lose their ability to break out of repetitive behavior patterns and become less creative and less cunning. 3 Essentially, stress changes the rodents’ behavior, predisposing the animals to doing the same things over and over. In commenting on the study, Robert Sapolsky a neurobiologist who studies stress at Stanford University School of Medicine, remarked, “This is a great model for understanding why we end up in a rut, and then dig ourselves deeper and deeper into that rut . . . we’re lousy at recognizing when our normal coping mechanisms aren’t working.” 4
Chronic stress can lead to a rut in which the wiring of our neural networks keeps us repeating the same dysfunctional behavior and hoping for a different outcome. As we experience depression and repetitive behaviors that stem from chronic stress, we’re less capable of analytic thought. The stress hormones released into the bloodstream keep us at a lower order of brain function, unable to attain synergy. Like iron and carbon, we remain brittle and easily afflicted, unable to find the strength of steel. We find it increasingly difficult to learn from past experiences, to alter the beliefs that cause us to re-create those experiences again and again, and to break out of
In times of danger, this chemical influx is necessary to help us fight or flee, but we can get locked into a state of chronic stress when the adrenal glands don’t receive a signal to stop producing these hormones. Unlike acute stress, which serves a positive purpose, chronic stress is very destructive. In Colonial times the legendary pirates of the Caribbean learned that citizens in a city under siege were more effectively worn down by the sound of cannons firing than by the actual damage done to their town by the cannonballs. This was because the sounds of the guns kept the townspeople in a state of chronic stress, unable to fight or flee, or get a good night’s rest. Long-term exposure to stress has very profound consequences.
THE DETRIMENTAL EFFECTS OF CHRONIC STRESS
Relating this information back to what we have already learned about the evolution of the brain, it’s important to note that the stress hormone cortisol, which is produced in excessive amounts when the HPA axis is locked in a state of chronic stress, increases the damaging effects of free radicals in the neurons of the hippocampus. This causes damage to the mitochondria, which in turn causes even more free radical production. The final act in this tragic play is that the hippocampal neurons themselves perish through the process of apoptosis. And when hippocampal neurons die, learning and creativity become almost impossible. And brain synergy is out of the question. The avoidance of pain overshadows natural curiosity; we hesitate to rock the boat; we hoard needlessly and risk foolishly. We become paralyzed by an inability to discover novel solutions and are unable to think or feel originally anymore. If we remain under acute stress long enough, our adrenals eventually give out and we become drained and exhausted.
In a recent study, Eduardo Dias-Ferreira and his colleagues at the University of Minho in Braga, Portugal, demonstrated that chronically stressed rats lose their ability to break out of repetitive behavior patterns and become less creative and less cunning. 3 Essentially, stress changes the rodents’ behavior, predisposing the animals to doing the same things over and over. In commenting on the study, Robert Sapolsky a neurobiologist who studies stress at Stanford University School of Medicine, remarked, “This is a great model for understanding why we end up in a rut, and then dig ourselves deeper and deeper into that rut . . . we’re lousy at recognizing when our normal coping mechanisms aren’t working.” 4
Chronic stress can lead to a rut in which the wiring of our neural networks keeps us repeating the same dysfunctional behavior and hoping for a different outcome. As we experience depression and repetitive behaviors that stem from chronic stress, we’re less capable of analytic thought. The stress hormones released into the bloodstream keep us at a lower order of brain function, unable to attain synergy. Like iron and carbon, we remain brittle and easily afflicted, unable to find the strength of steel. We find it increasingly difficult to learn from past experiences, to alter the beliefs that cause us to re-create those experiences again and again, and to break out of
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