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FYI
Neurophysiology of Brain-Gut Interactions During Stress
"Jack Wood, PhD
Professor of Physiology and Internal Medicine
Chairman Emeritus, Department of Physiology
The Ohio State University College of Medicine
Dr. Wood was the first to use microelectrodes to record the electrical and synaptic behavior of neurons in the enteric nervous system. He coined the term "brain-in-the-gut" in view of emerging evidence that the enteric nervous system had neurophysiological properties like the brain and spinal cord. In recent years he has focused on signaling interactions between the enteric immune system and the brain-in-the-gut during infectious enteritis and food allergy. In this lecture he shows how the central nervous system, enteric nervous system and intestinal immune system are integrated during physical and emotional stress to produce irritable bowel symptoms of diarrhea and abdominal pain and discomfort."
http://www.conference-cast.com/ibs/Lecture/RIDs/RID_BuildRegLecture.cfm
J Neuroimmunol. 2004 Jan;146(1-2):1-12. Related Articles, Links
Critical role of mast cells in inflammatory diseases and the effect of acute stress.
Theoharides TC, Cochrane DE.
Department of Pharmacology and Experimental Therapeutics, Tufts-New England Medical Center, Boston, MA, USA
Mast cells are not only necessary for allergic reactions, but recent findings indicate that they are also involved in a variety of neuroinflammatory diseases, especially those worsened by stress. In these cases, mast cells appear to be activated through their Fc receptors by immunoglobulins other than IgE, as well as by anaphylatoxins, neuropeptides and cytokines to secrete mediators selectively without overt degranulation. These facts can help us better understand a variety of sterile inflammatory conditions, such as multiple sclerosis (MS), migraines, inflammatory arthritis, atopic dermatitis, coronary inflammation, interstitial cystitis and irritable bowel syndrome, in which mast cells are activated without allergic degranulation.
PMID: 14698841
Does stress cause IBS or similar disorders in the GI Tract?
Does stress exassperate symptoms in patients who already have this disorder?
What kinds of stress are the worse and will problems go away if stress is decreased.
"These questions and many more like them are often asked by patients with GI disorders. They are also asked by physicians who are confronted with a confusing set of symptoms and few "objective" physiological markers for disease (like infections or blockage). As you might expect there are no simple answers, but new research has begun to point the way to a better picture of how stress and GI problems might be linked and even ways to address the role of stress in treatment.
The first thing to remember is that stress has a strong impact on the GI tract in everyone. It is well known that patients with IBS often report that stressful events precede the onset or exacerbation of IBS symptoms. In one survey study for example 73% of IBS patients reported that stress altered their stool pattern, and 84% reported that stress led to abdominal pain. Interestingly in the same study 54% of persons without IBS also reported stress altered stool patterns and 68% reported stress caused abdominal pain. While affecting everyone, stress does seem to more strongly impact GI function in persons with IBS or similar disorders, such as dyspepsia, or chronic heartburn.
In a recent study examining IBS patients over a several year period, up to 90% of the fluctuations in symptoms could be predicted by chronic stressors during the several preceding months. Another recent study examined patients who developed an acute GI infection (often after traveling in a foreign country). Most of the subjects recovered over a period of a few weeks with treatment but a significant percentage seemed to develop chronic symptoms similar to IBS. Level of stress during the three months prior to the infection was a strong predictor of who did and did not develop these chronic symptoms. Thus while stress is not the sole cause of IBS some stress clearly play a significant role in generating and prolonging symptoms in susceptible individuals, especially those with some GI symptoms. "
http://ibs.med.ucla.edu/Articles/PatientArticleFl99StressGI.htm
FYI
"Nervous System
"It would seem that our glands effect control
far above proportion to their size and this is
true. It is also true, however, that the glands
have their master, probably the most remarkable
creation of life's miracles - the human brain."
(Dr Bernard Jenson PhD)
When trying to understand stress, anxiety and depression it can help to have a very basic idea of how our nervous system functions and the role it plays in the stress response; this will help us to understand our psychological health problems more clearly.
The human nervous system is very complex, but basically it is like a telephone network, the main switchboard is the brain, with telephone cables (nerves) running from it down the spine connecting into every organ and system of the body. The nervous system communicates with the body in two ways - via chemicals called hormones and by electrical impulses that travel at a speed of 130 metres per second.
The nervous system is broken down into 2 major parts:
1. The Central Nervous System consisting of the brain and spinal cord.
2. The Peripheral Nervous System.
The peripheral nervous system further divides into the autonomic nervous system which is the part we are particularly interested in with regard to stress, anxiety, depression and its related problems.
THE AUTONOMIC NERVOUS SYSTEM
The function of the autonomic nervous system is to run all the automatic functions of the body like breathing, heart rate, digestion, endocrine (hormonal) system, etc.
The autonomic nervous system is divided into 2 divisions:
1. The Sympathetic Nervous System which initiates the stress response.
2. The Parasympathetic Nervous System which induces the relaxation response.
The body's organs and systems are supplied by nerves from the sympathetic and parasympathetic nervous systems which can slow them down or speed them up via hormones and electrical impulses depending on the situation.
Normally there is a balance kept between the sympathetic and parasympathetic nervous systems, but in long term chronic stress this balance can be disturbed and either one of the sympathetic or parasympathetic nervous systems can predominate over the other leading to stress related health problems.
THE FIGHT OR FLIGHT RESPONSE
When we perceive a real or imagined threatening stressor, the brain initiates the stress response by triggering a series of chemical chain-reactions that prepare the body for fight or flight. This reaction is a healthy, vital defense mechanism and triggers the release of hormones that affect every organ and system of the body. The hypothalamus, a collection of tissues in the brain, which then stimulates the pituatary gland in the brain which then stimulates the adrenal gland on top of each kidney to release its stress hormones. The stress response is the biological equivalent of a super charger on an engine.
The stress response hormones cause a number of biochemical and physiological changes which in the short term are vital and healthy but if the stressor is chronic then these stress hormones can start to undermine our health. Our stress response is designed to be triggered mainly in the short term.
In the long term these hormones cause blood clotting to increase and blood cholesterol levels to elevate increasing the risk of many diseases such as heart disease, stroke and angina. Stress hormones also weaken the immune system in the long term leaving us more vulnerable to infections. Increases in blood pressure are another long term effect of these stress hormones increasing the risk of stroke, heart attack and kidney disease. Chronically tensed muscles brought about by the stress response can lead to pain in the neck and back for example.
Excess cortisol in the blood interferes with mood enhancing neurotransmitters called serotonin. Disturbances in serotonin levels can be a factor in causing clinical depression and anxiety disorders as well as being linked to insomnia, obesity and increased sensitivity to pain.
Fortunately, the body has a compensating system which switches off the stress resopnse and releases chemicals that reduce blood clotting, reduce blood fats, lower blood pressure and heart and breathing rates.
NEUROTRANSMITTERS
The human brain weighs approximately 2 lbs, and it is 2 lbs of the most complex software on earth. It is so sophisticated it makes the most ultra modern super-computer look like an abacus in comparison. In the book, "The Healing Brain", Dr Robert Ornstein said we should see the brain not solely as an organ of rational thought but also as a gland. The brain is not just an organ used for thinking, it is a vast chemical manufacturing complex, producing many potent hormones called neurotransmitters which can have powerful effects on our psychological and physiological health.
Certain brain neurotransmitters have antidepressant and anti-anxiety effects and regulate appetite. Research indicates the balance of neurotransiiters affect everything from sleeping, waking, love, stress, anger, opetimism, pessimism, risk taking behaviour, aggression, drug abuse, alcohbol abuse, violence, anxiety, appetite etc.
Neurotransmitters are very powerful hormones that are secreted by the brain and nervous system and have a powerful effect on our psychological and physical health. To date more than 60 different neurotransmitters have been found and there are more to be discovered. These chemicals such as serotonin, adrenaline, noradrenaline, endorphins, dopamine, enkephalins etc., have a very powerful influence on our mood and to a degree on the way we think.
Research has indicated that our thoughts can influence these neurotransmitters in the brain. Serotonin for example, is positively enhanced by factors like healthy diet, laughter, exercise, but chronic stress can lower serotonin levels. Here then we can see biological and psychological factors at work influencing, among many other things, our mood.
PSYCHOLOGICAL INFLUENCES
Research on patient's brains scanned by Positron Emmision Tomography have indicated that the type of thoughts we have infleunce the balance of brain chemicals, so by learning to think more positively and realistically we can influence brain chemistry in a positive way, but other factors like an unloved, unsupported childhood can influence brain chemistry and physiology in such a way that it makes us less able to cope with stress in adulthood. If we think mainly negatively our brains secrete chemicals that can undermine our psychological and physiological health, whereas if we think more positively we can cause chemicals to be secreted that boost our psychological and physical health.
We also need to be aware that we are not exact carbon copies of each other, we have subtle biochemical and physiological differences that partially influence how we react to stress. For example each person's nervous system can react quite differently to any given stimuli or situation. Some people's nervous systems are more sensitive than others, more easily triggered by stress, and may also take longer to switch on the relaxation mode, once the stress response has done its job . There can also be differences in the amount of stress hormones we secrete in response to a stressor. People who have more of a tendency to being what is known as Type A personality are more reactive to stress and can produce up to forty times more cortisol (a stress hormone), they can produce four times as much adrenalin (another stress hromone),and also pump three times more blood to their muscles than the more laid back Type B personality.
This does not mean however that there is nothing that the more biologically reactive Type A's can do to reduce their stress. Research on Type A personalities who had suffered a heart attack showed that if they were taught stress management techniques then they could dramatically reduce their risk of a second heart attack when compared to Type A personalities who had not been taught stress management techniques.
BIOLOGICAL INFLUENCE
Our genes can also influence our brain biochemistry as can caffeine, alcohol, diet, exercise and stress. These factors can all have an impact in a positive or negative way on our brain chemistry and make us more vulnerable to developing stress, anxiety, depression, insomnia, etc.
NEUROTRANSMITTERS AND RISKY BEHAVIOUR
Depression and anxiety, Pre Menstural Syndrome, social phobia, anxiety, aggression, obsessive compulsive disorder, post traumatic stress disorder, violence, gambling, overeating, excess sex, drug abuse, have all been partly linked to low levels of neurotransmitters among other factors. Some people believe that those who participate in these risky behaviours do so because they want to and while this may be partly correct, the reason they are doing this is because it makes them feel better by boosting mood enhancing neurotransmitters which they may be low in, such as serotonin. It has been found that when, for example, an alcoholic's serotonin is boosted they loose the desire to drink in excess. This is how antidepressant drugs like Prozac work - they increase levels of serotonin which boosts mood and resolves depression.
This is a very basic explaination of how the nervous system works."
REFERENCES
http://stresshelp.tripod.com/helpline/id15.html
Harvard health
The Mind and the Immune System—Part I
One of the standing mysteries of medicine is the relationship between the mind and physical health—how feelings, thoughts, attitudes, and behavior are related to physical illness, how psychological and social stress affect the likelihood of developing a disease or the ability to resist it, and how counseling for emotional problems can aid recovery from illness. One of the clues to this mystery lies in the immune system, the network that defends us against microbes and other invaders. Interest in the connections between the brain and the immune system has given birth to the discipline of psychoneuroimmunology.
These systems communicate through the sympathetic nervous system and the endocrine glands, especially the hypothalamic-pituitary-adrenal (HPA) axis. Like the immune system, both are dedicated to the defense of the body against stress and danger, and both are directed from the same part of the brain, the hypothalamus. All three—the immune system, sympathetic nervous system, and HPA axis—respond to some of the same transmitter chemicals.
The sympathetic nervous system is part of the autonomic nervous system, which controls involuntary functions like heart rate, digestion, and breathing. The sympathetic nerves serve as an emergency response network, heightening the body's readiness to accept a challenge or escape in the face of danger. The sympathetic nerves are connected to various organs of the immune system, such as the thymus gland, the bone marrow, the spleen, and lymph nodes. Immune cells, including T cells, monocytes, and B cells, have receptors for the neurotransmitters released by sympathetic nerves. Damage to the hypothalamus and loss of sympathetic transmitters impairs the functioning of the immune system. An injection of antigens (foreign substances that activate the immune system) affects the concentration of sympathetic neurotransmitters in the brain.
Immune Learning
Animal experiments show that the immune system can "learn" by association. In one experiment, rats drank sweetened water containing a drug that causes nausea and depresses the immune system. They became so sick that they avoided sweetened water for some time after the drug was removed. That behavioral conditioning eventually was extinguished (wore off), and they returned to drinking the water—only to start developing infections at an abnormally high rate. Apparently, by association with the immunosuppressant drug, sugared water was provoking a conditioned response that continued to suppress the rats' immune systems even when it no longer affected their behavior.
Another experiment involved mice bred to be genetically vulnerable to an autoimmune disease (one in which an overactive immune system attacks the body's own tissues). They were given a flavored solution containing a drug that suppresses the immune system, delaying the onset of the disease. Then most of the drug was removed, but as long as the flavor remained, the rats continued to drink the liquid and resist the disease. The immune system had learned by association to suppress itself when the animals recognized that taste.
Conditioned learning can also enhance immune function, as another experiment showed. Mice were repeatedly forced to smell camphor while they were injected with a substance that stimulated the activity of natural killer (NK) cells, a type of white blood cell. When they were exposed to the smell of camphor without the injection, the activity of their NK cells still increased.
Hormonal Effects
The HPA axis regulates the body's activity through the circulation of the blood rather than directly through neural connections. The hypothalamus directs the pituitary gland to produce hormones that travel in the blood to the adrenal glands, where they cause the release of cortisol and other steroids as well as epinephrine (adrenaline) and its chemical relative norepinephrine (both of which also serve as neurotransmitters in the sympathetic system). These stress hormones influence the immune reaction through receptors on immune cells. Adrenaline, which prepares the body for immediate action, stimulates the immune system. One function of cortisol and related hormones (glucocorticoids) is to serve as a feedback mechanism that conserves energy by tuning down the emergency reaction when it is no longer needed. Rising cortisol levels signal the brain to shut down an immune response that threatens to become overactive.
There's evidence that stress is associated with depressed immune function in one or another part of the system. In one study, the activity of NK cells declined in medical students preparing for an examination. Those who felt calmer and had a slower heart rate also showed fewer immune changes. In another study, unemployment slowed the multiplication of white blood cells in response to antigens. A survey found that unhappily married women had lower numbers of certain immune cells than women with happy marriages. Elderly people caring for relatives with Alzheimer's disease have higher than average levels of cortisol and low levels of antibody response to influenza vaccine. Stress delays the production of antibodies in mice infected with influenza virus and suppresses the activity of NK cells in animals inoculated with herpes simplex virus.
Social stress can be even more damaging than physical stress. In a report published last year, some mice were put into a cage with a highly aggressive mouse two hours a day for six days. Other mice were kept in tiny cages without food and water for long periods. Both groups of mice were exposed to a bacterial toxin, and the socially stressed animals were twice as likely to die.
Severe depression resembles a chronic stress response, and depressed patients often lack the normal daily variation in the production of cortisol. Depressed patients seem to have lower NK cell activity than healthy controls, possibly because of high cortisol levels. In one study, the lymphocytes (a type of white blood cell) of depressed and bereaved persons responded sluggishly to the substances that normally stimulate them to proliferate.
Isolation can also suppress immune function. Infant monkeys separated from their mothers, especially if they are caged alone rather than in groups, generate fewer lymphocytes in response to antigens and fewer antibodies in response to viruses. Some studies have found lower NK cell activity in separated and divorced than in married men. NK cell activity also has been found to be lower in medical students who say they are lonely. In a year-long study of people caring for husbands or wives with Alzheimer's disease, changes in immune function were greatest in those who had the fewest friends and least outside help. In general, good social support is associated with better immune function in the elderly, even after correction for health habits, depression, anxiety, and life stress.
The effect of traumatic stress on the immune system has been studied occasionally. According to one report, four months after the passage of Hurricane Andrew in Florida, people in the most heavily damaged neighborhoods showed red uced activity in four out of five immune functions. Similar results were found in a study of hospital employees after an earthquake in Los Angeles. And a report published last year suggested that men with a history of posttraumatic stress disorder (PTSD), even long after apparent recovery, had lower numbers of various immune cells and lower levels of immune activity—possibly indicating a long-lasting suppression of the system. Another study found lower lymphocyte activity in abused women.
But it's not easy to generalize about the effect of stress hormones and sympathetic nervous system activity on immune functioning. Much depends on the individual, the timing, the kind of stress, and the part of the immune system under consideration. The results of studies on depression, for example, are conflicting; it does not consistently suppress any part of the immune system except NK cells.
Animal experiments suggest that the nervous system responds differently to acute and chronic stress. The acute stress reaction is often a healthy response to a challenge. But chronic stress may cause the feedback controls to fail, turning the emergency response into a condition that persists when it no longer has any use. Stress hormones and sympathetic activity remain at high levels, suppressing immune function and possibly promoting illness. The immune systems of people who are under chronic stress may also respond abnormally to acute stress.
The Difference it Makes
What matters most is whether the mind's influence on the immune system has the power to raise or lower the risk of illness or injury. On that issue only a little evidence is available.
Healing of injuries. One study found that the wound from a biopsy healed more slowly in women under high emotional stress. In another experiment, a wound healed more slowly in students when it was inflicted before an examination rather than just before vacation. Slow healing has also been found in people caring for Alzheimer's patients.
Colds and flu. Both observation and experiments suggest that stress makes people more susceptible to colds and other respiratory infections. In a one-year study, researchers asked 100 people to keep a diary recording their feelings and events in their lives. They were examined periodically for bacteria in throat cultures and virus antibodies in the blood. Stressful events were four times more likely to come before rather than after new infections. And people who developed a cold or other infection had often been feeling more angry and tense than usual.
In an English study published in 1991, 420 people were given nose drops containing a cold virus after answering questions about their personality, health practices, and behavior. They were asked about feelings of frustration, nervousness, anxiety, and depression and about events such as loss of a job or deaths in the family. When the subjects were quarantined and monitored for nine days, those under greater stress were more likely to catch a cold.
Researchers have continued to confirm this connection. In a study conducted in the late 1990s at the University of Pittsburgh, 276 healthy adults were given nose drops containing a cold virus. The symptoms were most severe in those who reported a high level of stress in their lives—but only when it was prolonged stress caused by such problems as unemployment and troubled marriages. Resistance to the virus was correlated with strong social support, especially a variety of contacts with family, neighbors, friends, workmates, and fellow members of voluntary organizations. This effect was independent of smoking, alcohol consumption, and quality of sleep. People with the weakest (least diverse) social ties were four times more susceptible to colds than those with the strongest ties.
Stress can also interfere with the response to a vaccine. In one study, flu shots were given to 32 people under high stress and 32 under low stress, matched for age, sex, and social class. The vaccine produced higher levels of antibodies in the low-stress group, and the high-stress people were more likely to become infected.
The University of Pittsburgh researchers found a close association between difficulties in coping with stress, flu symptoms, and a specific immune response. Fifty-five volunteers were given nose drops containing a flu virus after answering questions about their ability to handle stress in their lives. The people with the most stress-related problems produced higher concentrations of interleukin-6, a chemical messenger that attracts immune cells to the site of an infection. They also produced more mucus (had stuffier noses) and generally developed more serious symptoms in direct proportion to the rise in their interleukin-6 levels.
http://www.health.harvard.edu/hhp/article/content.do?id=537
IBS and the gastrointestinal Enteric nervous system.
http://www.fda.gov/fdac/features/2001/ibsside.html
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My website on IBS is www.ibshealth.com
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