Irritable Bowel Syndrome Message Boards

I have been posting this on other bb's, including my own, it is a lot of information but will post it here.

Stress and anxiety and worry and fear and all kinds of other things come into play in IBS, because of what's called the brain gut axis. This as I said is a lot of info, some very complex. It may take a while to read and learn some of these things.

know there is often talk on this discussion forum, on all the possible causes of IBS and little attension is payed to the suffering and emotional states of people with IBS and the fears and worries of what could it be and many other issues and how that really effects our symptoms.

But it would be good to think of another aspect of IBS which is very important, while they find the cause/causes for IBS and the suffering that people have now.

Changing your thoughts in IBS
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FYI

It is well known in IBS stress and anxiety can play a major role in triggering symptoms and contribute to making pain worse and effecting the colon. I would like this thread to be about such issues and psycophysiolgoical workings of the brain gut axis and psycophysiological arousal and distress, anxiety, antisipatory anxiety, and negative reaction to symptoms, and how calming the Mind and body often makes a significant difference in symptoms. I know for myself and many others, that the symptoms themselves are enough to contribute to negative thought processes and more anxiety and worry and anger and a whole array of negative thought processes. The longer a person has IBS, the deeper these thought processes can become imbedded in our thinking and in our mental states and the more a person suffers from the vicous cycle of IBS.

This is not to say IBS "is all in the head" it is not, it is a very real physical problem and that is well known by most nowadays hopefully.

First and this is bascially a form of CBT, this is on going to the dentist, but lets apply it to IBS and we can use our imagniantions and subsitute IBS for going to the dentist and how these negative thought processes effect the gut and gut function, which is also very well known now.

SO

The key to being relatively calm in the dentist's chair begins well
before the actual visit. I say relatively calm because if you're
suffering from dental phobia and have been for a while, it's unlikely
that you will feel "perfectly" comfortable your first or second visit.
Each of us must take an active part in overcoming our fears. People
don't get over their fear of heights for instance, in an flash. It takes
practice - practice changing your thoughts. Long before the
dreaded event you must take charge of your thinking. If you
consciously make an effort at being more calm, you will be more
calm.

Let's create a mental picture. You're sitting at your desk and glance
at the calendar. You notice your dental appointment is only two
weeks from today. Immediately your mind kicks into overdrive. "I
know it's going to be terrible. What if I get nauseous while I'm in the
chair? What if the anesthetic doesn't take hold quickly enough? I
know it's going to hurt. I'm grateful I found a new dentist who
advertises gentle procedures, but can I trust him to be gentle with
my mouth? Oh I remember that awful antiseptic stench from when I
was a youngster. I wonder if they've found anyway to correct that?"

As you think about the upcoming visit, your body begins responding
to your fear thoughts. Physical sensations can range from mild to
severe depending on how vivid a scene you've painted in your mind,
and how long you engage in the working up process. Your
shoulders and neck may feel tense. Your jaw may start to hurt
because you've got it got your teeth clamped together so tightly.
You may find yourself short of breath or a headache may be
looming on the horizon. Your stomach may be churning and your
insides trembling.

Actually these body signals can be viewed as good instead of bad.
They are a sure sign that you are thinking fear and a signal for you
to take action. You see the body doesn't know the difference
between an imagined experience and a real one. How can that be
you say! If you doubt my words, think about a frightful dream you
experienced, one where someone or something was chasing you.
You awaken from the dream feeling as though your heart is
pounding out of your chest, perhaps even perspiring. Your body
was reacting to an imagined fear, thoughts you were having in a
dream state. The character in your dream was not reality, yet your
body responded as if he were genuine.

Each and every time you catch yourself anxious about your
upcoming appointment, stop and W.A.I.T. Stop and ask yourself:
What Am I Thinking? Rather than letting your thoughts control you,
take the time to control your thoughts. Consciously toss out the
unhealthy fear thoughts and replace them with healthy secure and
realistic thoughts.

Using the picture we created earlier, here are a few ways to
reprogram what's going on in your mind. The original thoughts are in
italic, followed by the replacement thought(s).

Your dental appointment is only two weeks from today

You can view that fact insecurely, the appointment is only
two weeks away, or securely - the appointment is still two
weeks away.

I know it's going to be terrible

You really don't know how uncomfortable it's going to be.
The anticipation is always worse than the actual event.

What if I get nauseous while I'm in the chair?

Feeling nauseous is uncomfortable, but doesn't necessarily
mean that anything worse is going to happen. Feeling
nauseous is distressing, but it is not dangerous. Feelings
and sensations will rise, fall and run their course if we
don't attach danger to them. Take away the fear (danger)
and your stomach will quiet down on it's own accord.

What if the anesthetic doesn't take hold quickly enough?

If you feel the first poke of a dental instrument, speak up.
Tell the doctor it hurts. If you begin to feel pain while the
drilling's going on, hold up your hand as a signal to the
doc. You may not be able to speak clearly with the
position you're mouth is in, but you can make some kind of
sound, Grunt if you need to.- but do show some sign that
you're feeling pain. Remember your pain receptors are in
your body. Even though the dentists fingers are in your
mouth, he has no clue of what you're feeling unless you let
him know. Do not suffer in silence. And if you're concerned
about sounding a bit odd, don't. Dentists, assistants and
hygienists are used to hearing us
"talk with our mouths full."

I know it's going to hurt

The replacement thought here is simply: I don't know if it's
going to hurt - because you really don't know! None of us
can predict the future.

I'm grateful I found a new dentist who advertises gentle
procedures, but can I trust him to be gentle with my mouth?

Realistically there is no guarantee. But in all probability the
man or woman is more compassionate and caring than the
dentists of long ago.

Oh I remember that awful antiseptic stench from when I was a
youngster. I wonder if they've found anyway to correct that?

Most probably they have. New technology dentistry now
includes pleasant flavors for the things they place in our
mouths. If the flavors have improved, so have the scents.
Everything on the patient end of dentistry Is more
user-friendly these days.

And all those physical sensations you experience two weeks before
your appointment are the direct result of your fear thoughts - they
too are distressing, but they are not dangerous.

Practice in reprogramming thoughts has two beneficial effects. It
calms down the anticipatory fear you have before your visit, and
makes it easier to calm yourself down at the office. It's much easier
to recall secure and realistic thoughts if you've taken the time to use
them before. You can have them at your fingertips or the tip of your
tongue, ready to use while you're in the chair.

Another excellent method for stopping racing thoughts is objectivity
- the process of thinking of something measurable and verifiable.
This is a great technique to use, when you're stuck "in the chair."
Think about your automobile and picture every detail - interior and
exterior colors, number of doors, the shape of the door handles, all
the indicators on the dashboard, the type of fabric on the seats.
The list is endless. If you don't own an automobile, think of a
specific room in your home. Think about the size of the room -
length, width, height of the ceiling, how the furniture is placed, the
colors, lamps and all other accessories. It's a fact that we can only
have a single thought in a single instant. Describing in your mind
(thinking about) an object or objects that are familiar to you doesn't
give the mind a chance to harbor racing, upsetting thoughts. Fear
thoughts are persistent and they will try to sneak back in. When
they do, simply bring your attention (your thoughts) back to
describing your chosen object or place.

When you have a fear of dentists you really have the choice of two
discomforts -the actual discomfort you may feel during the
appointment (notice I said "may" have), or you have the discomfort
of not going and having the needed work done and beating yourself
up for giving into your fear. The dialogue goes like this: I'm such a
coward. But I can't help it. I'm scared. But I can't admit it to
anyone.

Every act of self-control produces a sense of self-respect. Along
with the relief you feel for having the dental procedure behind you
instead of staring you in the face, I guarantee you that when you
face your fear you will gain a realistic sense of self-pride. This next
step is important whether you do it immediately after you leave the
office or later on in the day - take time to give yourself a mental pat
on the back. You deserve it! No one else needs to be aware of it. It
was your effort that got you through. It's your victory and you can
be proud of it.

Whether your fear is dentists or tax audits, driving or diving, the
above tactics will work at reducing anxiety. If your anxiety has
grown into a full blown phobia, it's merely going to take more of
your effort. The key as with any life skill is do put to use what
you've learned. Changing thoughts is the first step in taking back
control of your life.

Print this article and carry it with you for easy reference. Memorize
and use the phrase "distressing but not dangerous." Do whatever it
takes to help you be an active participant in reprogramming your
mind.

It's true - Change your thoughts and change your life.

1998 Rose VanSickle

Author - Peace of Body, Peace of Mind

Does the above ring true for anyone, in going on long car rides for example or "where is the bathroom for example, or even anger in consitpation that you can't go or anxiety that you can go, which can contirbute to not going, or anxiety with d, which can contribute to d. ect. Or worry and anxiety the doctors have missed something which is causing your IBS Ect..

No problem Nancy, I can only but try to help explain some of the gut brain intereactions that are known to trigger symptoms. This is a very important part of IBS and IBS research and things they already know and understand about the disorder. I will keep posting more on it here, in the hopes it will help some understand the physical systems that the digestive system is connected too.

This is the actual the stress system and how it works and on a side not it is connected to fighting pathogens and threats to the digestive system.

Stress System Malfunction Could Lead to Serious, Life Threatening Disease

NOTE: IBS is not a serious life threatening disease that is just the name of the article with the information in it.

"The Stress Circuit

The HPA axis is a feedback loop by which signals from the brain trigger the release of hormones needed to respond to stress. Because of its function, the HPA axis is also sometimes called the "stress circuit."

Briefly, in response to a stress, the brain region known as the hypothalamus releases corticotropin-releasing hormone (CRH). In turn, CRH acts on the pituitary gland, just beneath the brain, triggering the release of another hormone, adrenocorticotropin (ACTH) into the bloodstream. Next, ACTH signals the adrenal glands, which sit atop the kidneys, to release a number of hormonal compounds.

These compounds include epinephrine (formerly known as adrenaline), Norepinephrine (formerly known as noradrenaline) and cortisol. All three hormones enable the body to respond to a threat. Epinephrine increases blood pressure and heart rate, diverts blood to the muscles, and speeds reaction time. Cortisol, also known as glucocorticoid, releases sugar (in the form of glucose) from the body reserves so that this essential fuel can be used to power the muscles and the brain.

Normally, cortisol also exerts a feedback effect to shut down the stress response after the threat has passed, acting upon the hypothalamus and causing it to stop producing CRH.

This stress circuit affects systems throughout the body. The hormones of the HPA axis exert their effect on the autonomic nervous system, which controls such vital functions as heart rate, blood pressure, and digestion.

The HPA axis also communicates with several regions of the brain, including the limbic system, which controls motivation and mood, with the amygdala, which generates fear in response to danger, and with the hippocampus, which plays an important part in memory formation as well as in mood and motivation. In addition, the HPA axis is also connected with brain regions that control body temperature, suppress appetite, and control pain.

Similarly, the HPA axis also interacts with various other glandular systems, among them those producing reproductive hormones, growth hormones, and thyroid hormones. Once activated, the stress response switches off the hormonal systems regulating growth, reproduction, metabolism, and immunity. Short term, the response is helpful, allowing us to divert biochemical resources to dealing with the threat."

http://www.nichd.nih.gov/new/releases/stress.cfm

The stress sytem is also part of all humans fight or flight system.

"What is the "fight or flight response?"

This fundamental physiologic response forms the foundation of modern day stress medicine. The "fight or flight response" is our body's primitive, automatic, inborn response that prepares the body to "fight" or "flee" from perceived attack, harm or threat to our survival.

What happens to us when we are under excessive stress?
When we experience excessive stress�whether from internal worry or external circumstance�a bodily reaction is triggered, called the "fight or flight" response. Originally discovered by the great Harvard physiologist Walter Cannon, this response is hard-wired into our brains and represents a genetic wisdom designed to protect us from bodily harm. This response actually corresponds to an area of our brain called the hypothalamus, which�when stimulated�initiates a sequence of nerve cell firing and chemical release that prepares our body for running or fighting.

What are the signs that our fight or flight response has been stimulated (activated)?

When our fight or flight response is activated, sequences of nerve cell firing occur and chemicals like adrenaline, noradrenaline and cortisol are released into our bloodstream. These patterns of nerve cell firing and chemical release cause our body to undergo a series of very dramatic changes. Our respiratory rate increases. Blood is shunted away from our digestive tract and directed into our muscles and limbs, which require extra energy and fuel for running and fighting. Our pupils dilate. Our awareness intensifies. Our sight sharpens. Our impulses quicken. Our perception of pain diminishes. Our immune system mobilizes with increased activation. We become prepared�physically and psychologically�for fight or flight. We scan and search our environment, "looking for the enemy."

When our fight or flight system is activated, we tend to perceive everything in our environment as a possible threat to our survival. By its very nature, the fight or flight system bypasses our rational mind�where our more well thought out beliefs exist�and moves us into "attack" mode. This state of alert causes us to perceive almost everything in our world as a possible threat to our survival. As such, we tend to see everyone and everything as a possible enemy. Like airport security during a terrorist threat, we are on the look out for every possible danger. We may overreact to the slightest comment. Our fear is exaggerated. Our thinking is distorted. We see everything through the filter of possible danger. We narrow our focus to those things that can harm us. Fear becomes the lens through which we see the world.

We can begin to see how it is almost impossible to cultivate positive attitudes and beliefs when we are stuck in survival mode. Our heart is not open. Our rational mind is disengaged. Our consciousness is focused on fear, not love. Making clear choices and recognizing the consequences of those choices is unfeasible. We are focused on short-term survival, not the long-term consequences of our beliefs and choices. When we are overwhelmed with excessive stress, our life becomes a series of short-term emergencies. We lose the ability to relax and enjoy the moment. We live from crisis to crisis, with no relief in sight. Burnout is inevitable. This burnout is what usually provides the motivation to change our lives for the better. We are propelled to step back and look at the big picture of our lives�forcing us to examine our beliefs, our values and our goals.

What is our fight or flight system designed to protect us from?

Our fight or flight response is designed to protect us from the proverbial saber tooth tigers that once lurked in the woods and fields around us, threatening our physical survival. At times when our actual physical survival is threatened, there is no greater response to have on our side. When activated, the fight or flight response causes a surge of adrenaline and other stress hormones to pump through our body. This surge is the force responsible for mothers lifting cars off their trapped children and for firemen heroically running into blazing houses to save endangered victims. The surge of adrenaline imbues us with heroism and courage at times when we are called upon to protect and defend the lives and values we cherish.

What are the saber tooth tigers of today and why are they so dangerous?

When we face very real dangers to our physical survival, the fight or flight response is invaluable. Today, however, most of the saber tooth tigers we encounter are not a threat to our physical survival. Today's saber tooth tigers consist of rush hour traffic, missing a deadline, bouncing a check or having an argument with our boss or spouse. Nonetheless, these modern day, saber tooth tigers trigger the activation of our fight or flight system as if our physical survival was threatened. On a daily basis, toxic stress hormones flow into our bodies for events that pose no real threat to our physical survival.

Once it has been triggered, what is the natural conclusion of our fight or flight response?

By its very design, the fight or flight response leads us to fight or to flee�both creating immense amounts of muscle movement and physical exertion. This physical activity effectively metabolizes the stress hormones released as a result of the activation of our fight or flight response. Once the fighting is over, and the threat�which triggered the response�has been eliminated, our body and mind return to a state of calm.

Has the fight or flight response become counterproductive?

In most cases today, once our fight or flight response is activated, we cannot flee. We cannot fight. We cannot physically run from our perceived threats. When we are faced with modern day, saber tooth tigers, we have to sit in our office and "control ourselves." We have to sit in traffic and "deal with it." We have to wait until the bank opens to "handle" the bounced check. In short, many of the major stresses today trigger the full activation of our fight or flight response, causing us to become aggressive, hypervigilant and over-reactive. This aggressiveness, over-reactivity and hypervigilance cause us to act or respond in ways that are actually counter-productive to our survival. Consider road rage in Los Angeles and other major cities.

It is counterproductive to punch out the boss (the fight response) when s/he activates our fight or flight response. (Even though it might bring temporary relief to our tension!) It is counterproductive to run away from the boss (the flight response) when s/he activates our fight or flight response. This all leads to a difficult situation in which our automatic, predictable and unconscious fight or flight response causes behavior that can actually be self-defeating and work against our emotional, psychological and spiritual survival.

Is there a cumulative danger from over-activation of our fight or flight response?

Yes. The evidence is overwhelming that there is a cumulative buildup of stress hormones. If not properly metabolized over time, excessive stress can lead to disorders of our autonomic nervous system (causing headache, irritable bowel syndrome, high blood pressure and the like) and disorders of our hormonal and immune systems (creating susceptibility to infection, chronic fatigue, depression, and autoimmune diseases like rheumatoid arthritis, lupus, and allergies.)

To protect ourselves today, we must consciously pay attention to the signals of fight or flight

To protect ourselves in a world of psychological�rather than physical�danger, we must consciously pay attention to unique signals telling us whether we are actually in fight or flight. Some of us may experience these signals as physical symptoms like tension in our muscles, headache, upset stomach, racing heartbeat, deep sighing or shallow breathing. Others may experience them as emotional or psychological symptoms such as anxiety, poor concentration, depression, hopelessness, frustration, anger, sadness or fear.

Excess stress does not always show up as the "feeling" of being stressed. Many stresses go directly into our physical body and may only be recognized by the physical symptoms we manifest. Two excellent examples of stress induced conditions are "eye twitching" and "teeth-grinding." Conversely, we may "feel" lots of emotional stress in our emotional body and have very few physical symptoms or signs in our body.

By recognizing the symptoms and signs of being in fight or flight, we can begin to take steps to handle the stress overload. There are benefits to being in fight or flight�even when the threat is only psychological rather than physical. For example, in times of emotional jeopardy, the fight or flight response can sharpen our mental acuity, thereby helping us deal decisively with issues, moving us to action. But it can also make us hypervigilant and over-reactive during times when a state of calm awareness is more productive. By learning to recognize the signals of fight or flight activation, we can avoid reacting excessively to events and fears that are not life threatening. In so doing, we can play "emotional judo" with our fight or flight response, "using" its energy to help us rather than harm us. We can borrow the beneficial effects (heightened awareness, mental acuity and the ability to tolerate excess pain) in order to change our emotional environment and deal productively with our fears, thoughts and potential dangers. "

http://www.mindbodymed.com/EducationCenter/fight.html

and when we talk about this keep this definition in mind. and also this article. But also keep in mind IBS is a physical problem, this is not "IBS is all in the head or psycobabble, but how all humans systems operate and the effects, as either a contributer to getting IBS in PI IBS studies or as a major trigger to IBSers, down to emotions, anxiety stress, worry, fear, pain, and the above mentioned feelings. But also later in ways work on these very real coordinated biological, behavioral, and psychological responses. "

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My website on IBS is www.ibshealth.com

Print Remind Me Notify Moderator

The Neurobiology of Stress and Emotions
By: Emeran A. Mayer, M.D., UCLA Mind Body Collaborative Research Center, UCLA School of Medicine, California

"We often hear the term "stress" associated with functional gastrointestinal (GI) disorders, such as irritable bowel syndrome (IBS). Many patients experience a worsening of symptoms during times of severely stressful life events. But what is stress? How often does it occur? How does our body respond to stress? This article explores the mechanisms that link stress and emotions to responses that have evolved to ensure survival and that, in the modern world, affect health�including gastrointestinal function. "

"Introduction
Stress is an adaptive response that is not unusual or unique to only certain individuals. In humans and animals, internal mechanisms have developed throughout evolution, which allow the individual to maximize their chances of survival when confronted with a stressor. A stressor in this context is any situation that represents an actual or perceived threat to the balance (homeostasis) of the organism. In a wide variety of real, life threatening situations -- such as an actual physical assault or a natural disaster -- stress induces a coordinated biological, behavioral, and psychological response. "

http://www.aboutibs.org/Publications/stress.html

This has to do with fear, the fight or flight and emotions and the brain. First is looking at these things like anxiety (mind chatter) and Fear (of symptoms say or getting in a car or where is the bathroom or when will the next pain attack start etc. )understanding them, then its how they apply to IBS and how to help change how we react.

But

Part 1

DISCOVER Vol. 24 No. 3 (March 2003)
Table of Contents

Learning Series: The Brain and Emotions - part 1
Fear
Recent research shows that when something bad happens to you, part of your brain begins thinking independently, storing its own memories so it can save you next time. That worked fine a million years ago
By Steven Johnson
Photograph by Elinor Carucci
Graphics by Don Foley

You are driving at night down a quiet suburban street, listening to Van Morrison's ''Brown Eyed Girl'' on the stereo. As you cross an intersection, your peripheral vision picks up the flash of headlights descending on the right side of the car. In the split second before you hear the sound of metal grinding into metal, your body tenses, blood flows to your extremities, adrenaline surges, and time slows down. At impact you find yourself noticing surreal details�the bright orange jacket of a startled pedestrian, the low-hung branches of a dogwood tree at the side of the road. After a split second that seems like 10 minutes, your car lurches to a halt against the curb.
The physical event of one car colliding with another has run its course, but its emotional impact continues. The adrenaline and other stress hormones released in your body have brought you to a state of almost superhuman alertness; you feel more awake than you've felt in your entire life. You can review the details of the crash as though you were replaying a DVD of the event, all the details immaculately preserved. For weeks, as memory fades, details continue to haunt you. Driving through an intersection causes you to flinch, anticipating another crash; the flash of headlights makes your gut tighten. For months, driving at night seems far more dangerous than driving during the day. Even a year later, the sight of drooping dogwood flowers triggers a sense of dread. Hearing ''Brown Eyed Girl'' brings the whole sequence back to consciousness with astonishing clarity.
Anyone who has been through a traumatic event will recognize this scenario immediately� the sudden physical response of fear and its often debilitating persistence in memory. The feeling of fear, like all emotions, is something that happens to the body and the mind. Few memories are as easily triggered and as hard to shake as those in which we are confronted with an immediate threat. For people who have undergone serious trauma, including war veterans and rape survivors, memories of fear can sometimes play a dominant role in shaping personality, a condition we now call post-traumatic stress disorder.
Unraveling the mystery of how the mind experiences fear� perhaps the most primal and enduring of all the emotions� turns out to be one of the most interesting and instructive quests in the annals of recent neuroscience. We have learned that fear plays tricks with our memory and our perception of reality; we have also learned that the fear systems in the brain have their own perceptual channels and their own dedicated circuitry for storing traumatic memories. As scientists have mapped the path of fear through the brain, they have begun to explore ways to lessen its hold on the psyche, to prevent that car accident from keeping us off the road months later.
It seems intuitive to us that we would remember vividly the details of a frightening event like a car accident. But here is a question with a surprising answer: Would we remember our fear if we had no long-term memory?
An experiment performed nearly 100 years ago by Swiss psychologist �douard Clapar�de provides a clue: Clapar�de was treating a woman suffering from a debilitating form of amnesia that left her incapable of forming new memories. She had suffered localized brain damage that preserved her basic mechanical and reasoning skills, along with most of her older memories. But beyond the duration of a few minutes, the recent past was lost to her� a condition brilliantly captured in the movie Memento, in which a man suffering similar memory loss solves a mystery by furiously scrawling new information on the backs of Polaroids before his memories fade to black.
Clapar�de's patient would have seemed straight out of a slapstick farce had her condition not been so tragic. Each day the doctor would greet her and run through a series of introductions. If he then left for 15 minutes, she would forget who he was. They'd do the introductions all over again. One day, Clapar�de decided to vary the routine. He introduced himself to the woman as usual, but when he reached to shake her hand for the first time, he concealed a pin in his palm.
It wasn't friendly, but Clapar�de was onto something. When he arrived the next day, his patient greeted him with the usual blank welcome� no memory of yesterday's pinprick, no memory of yesterday at all� until Clapar�de extended his hand. Without being able to explain why, the woman refused to shake. She was incapable of forming new memories, yet she had nevertheless remembered something� a subconscious sense of danger, a remembrance of past trauma. She failed utterly to recognize the face and the voice she'd encountered every day for months. But somehow, buried in her mind, she remembered a threat.

Click on the image to enlarge. (23k)
The amygdala, which directs signal traffic in the brain when danger lurks, receives quick and dirty information directly from the thalamus in a route that neuroscientist Joseph LeDoux dubs the low road. This shortcut allows the brain to start responding to a threat within a few thousandths of a second. The amygdala also receives information via a high road from the visual cortex. Although the high road encodes much more detailed and specific information, the extra step takes at least twice as long� and could mean the difference between life and death. LeDoux says the disconnection between the two routes may underlie some disorders: "While in terms of survival it may be better to mistake a stick for a snake, people who have pathological fears may be treating sticks as snakes much of the time."
� Jocelyn Selim

About 25 years ago, a young postdoctoral student at weill Medical College of Cornell University in Manhattan named Joseph LeDoux was casting about for a research focus. Cognitive science, with an emphasis on computer modeling, was the hot new field. But LeDoux was interested in emotions, and "there wasn't a lot going on there,'' he remembers, sitting in his office at New York University, where he is a professor of neural science. ''So I read around and came across studies on fear conditioning." Clapar�de's pin turns out to be a somewhat diabolical twist on the classic behaviorist experiment of fear conditioning: Put a rat in a cage, play a tone, and simultaneously deliver a shock to the animal. After a few rounds of tone and shock, the rat starts to fear the tone even if it's not accompanied by the shock. The fear reaction� noticeable because the rat freezes in place� has been observed in species as diverse as pigeons, rabbits, baboons, and humans. It is called a conditioned response. The rat has an unconditioned innate fear of shocks, but it can be conditioned to be afraid of tones if the two are associated with each other. In Clapar�de's version of the experiment, the pin was the shock. His outstretched hand was the tone. After only one exposure to the shock and the tone, the amnesiac patient acquired a conditioned fear response to shaking hands with her doctor.
Conditioned fear is easy: Fruit flies, marine snails, even lizards can be trained to display defensive behavior in response to threatening stimuli, along the lines of the tone and shock experiments. Conditioned fear turns out to be one of the most essential techniques that natural selection stumbled across to increase the survival odds of organisms in an unpredictable environment. But until a few decades ago, we had almost no idea how that learning actually took place. The ubiquity of conditioned fear in the animal kingdom, combined with the amnesiac's ability to remember potential threats, made it clear that learning to be afraid involved different mechanisms than, say, learning how to ride a bicycle or memorizing the capitals of all 50 states. But what was the mechanism? That's what LeDoux set out to determine. There had been almost no research into how the fear response actually came into being. ''In fact,'' LeDoux says with a smile, ''my first grant on this topic in the early 1980s was turned down," because scientists reviewing his application believed it was impossible to scientifically study emotions.
LeDoux forged ahead anyway. ''I started from the outside,'' he says. ''I had the sound that produced the fear response. I wanted to know: How does that sound go through the brain and create the response?'' Like most brain researchers in the age before advanced imaging technology, LeDoux's approach was surgical subtraction. Take a healthy rat and begin extracting specific parts of his brain. If you remove a region and the rat can still learn to associate the tone with the shock, then the region you've removed isn't relevant to fear conditioning. But if the rat stops learning, you know you've got something relevant.

Click on the image to enlarge. (85k)
ANATOMY OF FEAR

Within seconds of perceiving a threat, the primitive amygdala sounds a general alarm. The adrenal system promptly floods the body with adrenaline and stress hormones. Nonessential physiological processes switch off. Digestion stops, skin chills, and blood is diverted into muscles in preparation for a burst of emergency action. Breathing quickens, the heart races, and blood pressure skyrockets, infusing the body with oxygen while the liver releases glucose for quick fuel. The entire body is suddenly in a state of high alert, ready for fight or flight.
� J. S.

''Because the auditory pathways are fairly well worked out in mammals, I could use that as a starting point. I started with the top of the auditory pathway, which is the auditory cortex. I took that out, and the animals learned fine. Then I went down one station to the auditory thalamus, took that out, and they couldn't learn at all. So that meant that the sound had to go through the system to the level of the thalamus but didn't go through the cortex. So where was it going?'' The question was puzzling because the traditional understanding of the brain's activity emphasized the role of the cortex over most other regions. The cortex was where the sensory information� in this case, the sound of the tone� was integrated into conscious awareness, alongside other sensory data transmitted from other parts of the brain. The auditory thalamus was supposed to be just a relay station from the ear to the primary destination, the auditory cortex. So there was something strangely inverted about LeDoux's result. You could eliminate the primary destination altogether without affecting the learning, but if you took out the relay station, the learning stopped.
LeDoux's assumption was that the auditory thalamus harbored a link to another part of the brain, in addition to its link to the cortex. Using a tracer dye to follow pathways out from the auditory thalamus, LeDoux discovered a connection to the amygdala, an almond-shaped region in the forebrain long associated with emotional states. When he removed the amygdala, the rats failed to learn. Perusing the literature, he found earlier experiments that demonstrated a crucial part of the amygdala known as the central nucleus contained links to the key brain stem areas that control the autonomic functions involved in the fear response, like acceleration of breathing and heart rate. ''I didn't start out looking for the amygdala,'' LeDoux says. ''The research led me to it.''
The key insight that emerged is that the experience of danger follows two pathways in the brain: one conscious and rational, the other unconscious and innate. These were quickly dubbed the high road and the low road. Say you're walking though a forest, and out of the corner of your eye you detect a slithering shape to your left, accompanied by a rattling sound. Before you even have time to formulate the word snake, your body has frozen in its tracks; your heart rate has accelerated; the sweat glands on your palms have dilated. In your brain, the information flow looks something like this: Your eyes and ears transmit basic sensory information to the auditory and visual thalamus, where the information is then transmitted along two paths. One stream of data heads towards the cortex, where it will be integrated with other real-time sensory data, along with more elaborate associations like the word rattlesnake, or your childhood memories of a pet python, or the snake scene from Raiders of the Lost Ark. At the same time, the slithering is also transmitted� in less rich detail� to the amygdala itself, which blasts out an alarm to the brain stem, alerting the body that a potential threat is nearby. The key difference between the two paths is data transmission time. It might take a few seconds to establish the presence of the snake and formulate a response via the high road, but the low road kicks the body into a freezing response within a fraction of a second. And you don't have to learn the elaborate bodily choreography involved, the way you might learn a complicated yoga position. Your body knows how to execute the freezing response without any training at all. In fact, it knows the response so well that it is nearly impossible to keep it from happening.
As a survival mechanism, LeDoux's low road made perfect sense. But other questions remained: How did the amygdala know to be afraid of a snake in the first place? How could Clapar�de's patient learn to be afraid if she lacked memory?
We're accustomed to describing someone as having a good or a bad memory, as though memory were a single attribute that covers the entire range of storing and recalling information. We now know that the brain's memory systems are far more diverse than this. There are systems devoted to explicit or declarative memories, like your childhood recollection of that pet python, and systems devoted to procedural memories that usually involve physical movement, like learning how to ride a bicycle. And then there are emotional memories. If you watch the activity in someone's brain using a modern fMRI scanner, you see a different profile depending on which kind of memory the subject is conjuring up.
In ordinary cases of fear conditioning� encountering that snake in the grass� a declarative memory will occur more or less simultaneously with an emotional memory. You'll feel the freezing response kick in, and moments later you'll remember seeing that scene from Raiders of the Lost Ark. The latter feels like our traditional idea of memory; there's a mental picture from the past experience that comes into consciousness, as though you were sifting through pages of a photo album. The transition to a freezing response doesn't feel like a memory in that conventional sense of the term, but for all intents and purposes it is one. It is recalled information from past experience that alters your state of mind. The transition to a freezing response happens too fast for it to be a conscious, deliberate memory, but it's a form of memory nonetheless.
In brain anatomy terms, the declarative memory of Indiana Jones in the snake pit is laid down by the hippocampus, a long, curved ridge located next to the amygdala. The emotional memory of a threat, on the other hand, is mediated by the amygdala itself. This explains the mystery of the remembered pinprick: Clapar�de's patient lacked the ability to form declarative memories, but she had a functioning amygdala that kept the memory alive, albeit unconsciously. If you had a past encounter with a snake and you felt actively threatened, a trace of that memory would have been stored by the amygdala as well as by the hippocampus. Some brain scientists believe that our fear systems are prepared to learn about threats� snakes, spiders, or heights� that have been major obstacles to survival over the millions of years it has taken the modern brain to evolve, which explains why it is easier to develop phobias about snakes than about threats that are statistically much more likely to kill you, such as electricity.
Some scientists believe the amygdala doesn't have its own discrete storage system for emotionally charged memories but rather marks memories created by other brain systems as being somehow emotionally significant. In 2001 James McGaugh of the University of California at Irvine conducted a telling variation on the classic fear-conditioning experiment. He took a rat and subjected it to the traditional foot shock if the animal took a step. After administering the shock, McGaugh injected cyclic AMP� a cellular messenger that strengthens neuronal synapses, leading to stronger memory� into the animal's cortex. Two days later, the rats were tested to see how well they were conditioned; those that received the injections turned out to have enhanced memories of the shock. ''So we know the cortex is involved in the memory that's based on fear in that situation,'' McGaugh says. ''Now, if we make a lesion of the amygdala, the stimulation of the cortex doesn't do anything. In other words, you have to have a working amygdala for the cortex to do its job.''
McGaugh concludes, ''That experiment tells me that fear is not learned in the amygdala. Amygdala projections are coming up to brain regions where information is being stored, and they're saying: 'You know this memory you're storing? Well, it turns out to be a very important one, so make it a little stronger, please.' It provides selectivity in our lives. You don't need to know where you parked the car three weeks ago, unless it was broken into that day.'' You can think of it as the brain's way of underlining.

Neuroscientists have determined that the memory of a fear stimulus triggers dramatic changes in the vital signs of rats. In a series of conditioned-response experiments, rats are first exposed to a painful shock accompanied by a tone. Whenever the tone is repeated, the rats immediately stop dead in their tracks. Blood pressure shoots up within three seconds, and heart rate peaks within five seconds. After 20 seconds, increased levels of stress hormones like corticosterone flood the body, and highly oxygenated and fuel-charged blood is pumped into the muscles to prime them for action.

The trouble with emotional memories is that they can be fiendishly difficult to eradicate. The brain seems to be wired to prevent the deliberate overriding of fear responses. Although there are extensive neural pathways from the amygdala to the neocortex, the paths running the reverse direction are sparse. Our brains seem to have been designed to allow the fear system to take control in threatening situations and prevent our conscious awareness from reigning.
This may have been an optimal design for predator-rich environments in which survival was a minute-by-minute question, but it is not a good adaptation for modern environments in which the stressors can be job performance reviews. The amygdala may be looking out for your best interests by preserving a memory of that nighttime car accident, but if the result is an inability to drive after dark, the fear circuitry has gone too far. Because the low-road memories are so tenacious, one question neuroscience is now wrestling with is how to subdue the amygdala when those memories hurt the organism.
As a New Yorker who works in downtown Manhattan, LeDoux has been thinking a lot about these issues since September 11, 2001. Many local residents experienced a conditioned fear response that day, making it hard for them to work in tall buildings or visit the downtown area. LeDoux suspects those traumatic memories will persist in the brains of New Yorkers. The treatment possibilities are not about eliminating the memories so much as retraining the amygdala to respond differently when those memories are triggered.
''The contrast,'' LeDoux says, sitting in his university office above Washington Square Park, with Ground Zero lurking not far to the south, ''is between taking action and being stuck, frozen in fear, headed toward despondency, unable to control your life. There's an interesting experiment along these lines: You have a rat that goes into a chamber. A tone goes off, and he gets a shock, and he freezes with the fear response. The next day he goes into chamber B, the tone goes off, and he freezes. But if he takes a step, the tone stops. Eventually he learns that he has to crawl across the chamber to eliminate the tone completely. So by taking that action, he's able to prevent fear from existing in his life.
''In order for the rat to do this,'' LeDoux continues, standing up to sketch out his ideas on a cluttered white board, ''he's got to throw a switch in the amygdala. Normally, the fear response goes from the lateral nucleus to the central nucleus and then out of the amygdala. In order for the rat to take a step, the stimulus has to go not to the central nucleus but to the basal nucleus, and then out to the parts of the brain that are involved in active behavior.'' In other words, the amygdala wants to associate the memory with the freezing response, but it can be trained to associate it with something less debilitating. When you hear an airplane rumbling overhead, you can freeze, or you can take a step. And with every step you reroute the path of fear through the amygdala.
Our new understanding of fear has also led to cunning pharmacological treatments for post-traumatic stress disorder. McGaugh talks about two recent studies that involved giving beta-blockers to people who had recently suffered a traumatic event, studies that built on McGaugh's own research: ''Say you have a traumatic experience. The memory of that experience will pop into your brain the next day, whether you want it to or not. And when that memory pops into your brain, you're going to have that whole autonomic response that you had originally. It's going to come back again. So it's not only that you remember that you were mugged, but you also get very emotionally excited about it when the memory happens.'' That emotional excitement triggers the memory-enhancing cycle all over again, making the traumatic memory even stronger, like a spinning tire deepening the muck hole it's stuck in with each jab on the accelerator. By preventing the autonomic reaction, beta-blockers keep the memory from forming deeper grooves in the brain, making post-traumatic stress symptoms less severe, ''which I think is a really interesting development,'' McGaugh says with a hearty laugh. ''Forty-five years of my life I've spent studying rats and out pops something useful!"

Because the fear response can play a direct role in life-and-death struggles, it's not surprising to find that the brain contains elaborate machinery dedicated to its routines. The fact that the amygdala's basic architecture reappears in so many species is testimony to its evolutionary importance: Natural selection generally doesn't tinker with components that have proved essential to basic survival. Of course, the persistence of the low road in a world where predators are largely nonexistent may no longer be adaptive, but that's the trade-off of human culture. Evolution made our brains so smart that we ended up building environments that made some of our mental resources obsolete. No matter how calculating and erudite the neocortex becomes, it can't simply switch off the amygdala. In that sense, you can see the battles between these different regions as a re-enactment of Freud's clash between man's civilized superego and his primal id.
There is great elegance in the way this system has evolved, with its complex mix of instinct and learning. Like all emotions, the fear circuitry steers the organism toward desirable states� away from predators or other threats� without knowing that much in advance about the world that the organism will actually inhabit. We are not slaves to our emotions, but they are hardly at our beck and call either. They propel us in directions that our rational minds don't always understand� fear most of all. The amygdala, like the heart in Pascal's famous phrase, has reasons of which reason knows nothing.

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