Making a super-simple glossary of brain science

HPA Axis – hypothalamus pituitary adrenal



Group of organs that control the stress response



The interactions among these organs constitute the HPA axis, a major part of the neuroendocrine system that controls reactions to stress and regulates many body processes, including digestion, the immune system, mood and emotions, sexuality and energy storage and expenditure



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Allostatic Load;is defined as the physiological consequences of chronic exposure to fluctuating or heightened neural or neuroendocrineresponse that results from repeated or chronic stress


Allostatic load starts to accumulate from before birth and with each demand on the nervous system or body it accumulates as an increasing load on the organism. The body tabulates the total life stress load and once it reaches their genetic threshold it will be expressed as disease or psychological dysfunction.

Four conditions that lead to allostatic load are:

• Repeated frequency of stress responses to multiple novel stressors;
• Failure to habituate to repeated stressors of the same kind;
• Failure to turn off each stress response in a timely manner due to delayed shut down; and
• Inadequate response that leads to compensatory hyperactivity of other mediators.

 

All of which occur in family and social situations where you're cut off from the real world of nature and its link with your thinking body. The natural stresses created by rain, snow, ice, wind and rocks only build self-confidence and self-reliance. Dealing with those kind of stresses don't tear you down, they build you up inside.

 

We are designed to handle immediate problems even if major - it is the drip....drip...drip of non-stop stress that causes a breakdown

 

Yes, direct, empirical emergencies - like a big storm, a river crossing, or an avalanche - can be dealt with on the spot and when they're over, they're over and you can kick back and relax, even feel refreshed and strengthened. But working in a Silicon Valley start 'em up that's going down is a daily 8 to 5 stress machine where people start acting out and picking on each other in the false hope that they won't be the one to get fired (even though everyone is going to get it if sales don't pick up). I've been in three of those, but didn't have as much responsibility as the other employees who certainly didn't welcome being canned so they could go do something more fun. Always nicer if you're the one who's not implicated - the question mark. However, taking care of my parents after they collapsed, working two jobs, managing a wrongful death law suit, burying dad, and being a care-giver for my mom with dementia now that's a different kettle of fish as far as stress is concerned. It's just how much your psychological "center" is threatened that determines how much you're stressed out. Grad school was stressful, sure, but when you know that afterwards you're moving to Yosemite and having fun, the pressure isn't nearly so great. Living on the street in a homeless encampment - hard to imagine that kind of stress. No wonder they turn to crystal meth and alcohol. Probably the only time they feel half-assed human.

 

Forest, you don't say from which one of Prof Sapolsky's books this quote is taken? It can't be from his videos in the Media section.

I see where Robert Sapolsky has a new online course on what it means to be human:

http://www.thegreatcourses.com/tgc/...anada,+United+Stat2&utm_content=Robert+Sapols

 

Lets dumb this down a bit. Body tension has two primary functions: the first is the flight/fight stress mode – to run like hell or stand and battle which produces tension as an activity readiness. The second is the freeze mode which produces tension as a body armor.

The limbic-hypothalamic-pituitary-adrenal axis is the threat response system that activates this fight/flight/freeze response and creates the body tension. Once this system is activated it alters the balance of almost all the neurotransmitters in the body including dopamine that can cause severe muscle pain and stiffness.

The bodies hormone and neurotransmitters are not in isolation. They play as a symphony so when you alter one you alter many.

The hippocampus is part of the shut-off feedback loop for the LHPA axis and is damaged by allostatic load and stress. The usual prodromal of allostatic load is psychological and functional symptoms, not disease.

I respect Dr. Schubiner and his work but he is human and limited in the amount of data he can learn. He did not know about the effect of NutraSweet on muscle tension. Aspartame can have profound effects on muscle pain as can over the counter remedies, prescription drugs and minor dehydration.

 

Autonomic overload is a non-medical term used for easy understanding. A more accurate term is sympathetic dominance where the sympathetic system gets turned on and fails to shut off.

Our unique large cortex enables us to do much of what makes us human – it is also a curse. We can create mental pictures, thoughts and psychological disturbances animals are not able to do. An animal can not sustain a stress response unless there is an outside stressor – humans can flog ourselves for years....a lifetime with no external stress.

We also know that a mother under stress while pregnant passes along these stress chemicals to the fetus permanently altering their stress response system, this also occurs in children in adverse condition families. It is not a coincidence that most TMS people had stressful childhood experiences, and it need not be major trauma if the child is genetically sensitive. For some children an absent parent such as day care is enough.

 

I know Robert Sapolsky and also know he basically a researcher on stress and is especially interested in social structures and stress. He is not a clinician –clinicians work with the outcomes from stress, researchers do not.

Things can be very “Broken” and be functional disorders. What they don’t include is measurable structural damage, no tumors, injury, cellular damage, pathogens etc. Most psychological disorders are functional in that our scans and tests can only show the outcome of the dysfunction and not the cause. Even then there are no tissue changes.

A simple definition of stress is when an organism is asked to respond to change or threat. Allostatic Load is the genetically predetermined number of times an organism (or piece of steel) can respond to challenges before a threshold is reached and the organism breaks (how may times can you bend a piece of steel before it snaps).

Before it breaks it overloads or is reaching final threshold but has not yet snapped (major disease or death). TMS is the overload phase, the body is saying I have endured all I can and remain normally functional.

Change + Threat = stress.
Stress x sum of lifetime events = Allostatic load
Sum of Lifetime Allostatic Load ./. (divided by) Genetic Resilience = Tolerance to Breakdown
Breakdown Expression is the result of genetics – personality – history & type of load

The LHPA axis is the system that responds to threat or change so Allostatic Load is the number of times it has been called on to respond. TMS is part of the exhaustion phase Dr. Hans Selye identified. We are not designed to breakdown during the alarm or resistance phases – only the exhaustion phase.

Unlike Zebras we can call on the LPHA axis constantly with psychological and thought issues that keep us in chronic exhaustion phase. Add too much physical activity, poor diet, dehydration, environmental stressors such as too much heat or cold, too much incoming stimuli (arousing TV, events, social life etc) medications and drugs, lack of sleep, illness, responsibilities and you have more piles on the Allostatic Load truck

EXHAUSTION STAGE -
At this phase, the stress has continued for some time. Your body’s ability to resist is lost because its adaptation energy supply is gone. Often referred to as overload, burnout, adrenal fatigue, maladaptation or dysfunction – Here is where stress levels go up and stay up!
The adaptation process is over and not surprisingly; this stage of the general adaptation syndrome is the most hazardous to your health.
Chronic stress can damage nerve cells in tissues and organs. Particularly vulnerable is the hippocampus section of the brain. Thinking and memory are likely to become impaired, with tendency toward anxiety and depression. The hippocampus is also a main regulator of the stress response and once damaged may not be capable of shutting the stress response off.
There can also be adverse function of the autonomic nervous system that contributes to high blood pressure, heart disease, body pain, psychiatric disorders, rheumatoid arthritis, and other stress related illness.

 

Speaking of the exhaustion phase, last night I just happened to glance at this passage in Anthony Beevor's new magisterial history, The Second World War (2012):

When the German 6th Army in Stalingrad had been reduced to a diet of Wasserzuppe - a few pieces of horse-meat boiled in melted snow, the army's pathologist, Dr Hans Gergensohn, who had been flown into the pocket in December 1942, "soon came to an alarming discovery after carrying out fifty autopsies. Soldiers were dying of hunger far more rapidly than they would in other circumstances. This, he concluded, came from the interacting effect of stress, prolonged malnutrition, lack of sleep and intense cold. This interfered with the body's metabolism. Although the soldier might have consumed a few hundred calories worth of food, his digestive system absorbed probably only a fraction. The resulting weakness also reduced his ability to survive disease. Even those who were not ill were far too weak to attempt a breakout through deep snow." (p. 396)

In other words, the German soldiers in Paulus's 6th Army were so run down that they couldn't digest food and absorb calories from it due to the extremely stressful environment they found themselves in. This makes you wonder if pure psychological stress becomes too great will it also interfere with the operation of your basal metabolism? Could self-imposed psychological stress become so great that it would lead to self-extinction? Makes you think about such old adages as "Dying of a broken heart" and so on.