Thursday, August 01, 2013

Melzack & Katz, Pain. Part 17g: Stress conceptualization through the ages

The paper, Pain.

Part 17: The stress of it all Part 17b: Stress and adrenals Part 17c: Women, pain, and stress Part 17d: Stress, aging, and pain Part 17e: Stress and aging, keeping hippocampal dendrites fluffed up Part 17f: Chrousos and Gold and stress


We're about to set sail again, continue down the river. Here we go. Nice day for travelling. 


We are examining the paper that Melzack and Katz seem to love so much, Chrousos and Gold 1992

We are about to travel through the history of stress research. Researchers, especially medical resesarchers, love to travel back to
ancient times to find the first wisps of whatever it is they have spent their lives furthering. 

Chrousos and Gold start with Heracleitus, "the first to suggest that a static, unchanged state was not the natural condition, but rather that the capacity to undergo constant change was intrinsic to all things."

Judging by his angsty-looking visage, it would seem he felt.. well, "stressed" by the thought, "You can't step in the same river twice" instead of freed by it..  must have been a different context. 

Good for him, though, for seeing "ever-present change in the universe" as real, and holding it forth as truth. 

Next, Empedocles is mentioned.. he proposed "that all matter consisted of elements and qualities in a dynamic opposition or alliance with one another," and that "balance and harmony was a necessary condition for the survival of living organisms." 

He's credited with originating the idea of four basic substances, although I suspect that idea was likely invented in all cultures independently - it turns up all over the place. 

He supposedly died by throwing himself into a volcano. Maybe he just couldn't take the stress of it all anymore. 

Hippocrates "equated heath to a harmonious balance of the elements and qualities of life and disease to a systemic disharmony of these elements." You come across the
weirdest little factoids reading papers like this..  

Chrousos and Gold say that the terms "dyscrasia" and "idiosyncrasy" derive from Hippocrates' ideas about health and disease and mean defective or peculiar ways the elements became mixed. (I wonder if that's where the word "crazy" came from. But I digress.)

Hippocrates apparently thought nature could fix most things, as nature had "caused" them in the first place. 

Meanwhile, one of his contemporaries, Epicurus, proposed that "mind could be among or influence these healing forces." He advocated that everyone try to cultivate a state of mind he called "ataraxia" - imperturbability. [I dunno... he looks a bit perturbed to me with that furrowed brow..]

Actually, cultivation of ataraxia does not sound like a bad idea. Not at all. Of course, a lot depends on what culture you are born into and whether you're born male or female, how you're going to hope to achieve this.. but I think it can be done. I'm still trying. It's not just a good way to live, I'm sure it would also be a good way to die, i.e., unperturbed by dying.

Chrousos and Gold skip forward - way forward - to the Renaissance, to Thomas Sydenham, supposedly the "father of English medicine" according to Wikipedia.
Thomas Sydenham
They say, "Thomas Sydenham extended the Hippocratic concept of disease as a systematic disharmony brought about by disturbing forces, when he suggested that an individual's adaptive response to such forces could itself be capable of producing pathological changes."

[So, I think that means, Sydenham suggested we can bring on our own disease by how we think.. ah, so this might be why doctors, even today, tend to blame patients for bringing on their own diseases. I think this is a point we should return to. Maybe a bit later. Let's stay on track for now, until we are done with the rest of this history section.]

Claude Bernard

Chrousos and Gold move on to the ideas presented by Claude Bernard in the 19th century, who came up with the concept of milieu intérieur, or "principle of a dynamic internal physiological equilibrium."

Wikipedia defines milieu intérieur as "extra-cellular fluid environment, and its physiological capacity to ensure protective stability for the tissues and organs of multicellular living organisms." 

[Off the top of my head I remember something from the gliopathy paper about extracellular environment, something about too much ATP (I think), out in it, which stimulated the nearby cells to make a bunch of receptors which made them be more provoked by all the signalling molecules which cascaded into more sensitivity to nociceptive input and facilitated eventual neuropathic pain, something like that.. but I don't trust my own memory.]

Anyway, back to the paper: upon Bernard's idea was built the concept of homeostasis by Walter
Walter Cannon
Cannon a bit later, Chrousos and Gold say. Cannon also added emotional parameters to this idea. He also described the fight/flight response, and "linked the adaptive response to stress with catecholamine secretion and actions."

A bit later in the 1930's, Hans Selye came along and expanded the field. He came from Hungary and ended up at McGill and U Montreal. Yet another connection to Melzack.

Back to his contributions to stress research - there are tons. 
Here is how Chrousos and Gold describe it: "In the 1930's, Hans Selye borrowed the term "stress" from physics and set it to mean the mutual actions of forces that take place across any section of the body. He hypothesized that a constellation of stereotypic psychological and
Hans Selye
physiological events occurring in seriously ill patients represented the consequences of a severe, prolonged application of adaptational responses. He referred to this state as the "General Adaptation or Stress Syndrome" and, in effect, redefined Sydenham's concept of diseases of adaptation."

Selye figured out that not all stress is bad. He coined the term "eustress" to describe the kind that is useful to the organism, as opposed to dis-stress, which isn't. Exercise falls under eustress, usually.

Chrousos and Gold say this: "[Selye] believed that mild, brief, and controllable states of challenged homeostasis could actually be perceived as pleasant or exciting and could be positive stimuli to emotional and intellectual growth and development. It was the more severe, protracted, and uncontrollable situations of psychological and physical distress that Selye believed led to frank disease states."

Next we'll look at their next section on stress syndrome, the phenomenology and physiology.

Previous blogposts

Part 1 First two sentences Part 2 Pain is personal Also Pain is Personal addendum., Neurotags! Pain is Personal, Always.

Part 3a Pain is more than sensation: Backdrop Part 3b Pain is not receptor stimulation Part 3c: Pain depends on everything ever experienced by an individual

Part 4: Pain is a multidimensional experience across time

Part 5: Pain and purpose

Part 6a: Descartes and his era; Part 6b: History of pain - what’s in “Ref 4”?; Part 6c: History of pain, Ref 4, cont.. : There is no pain matrix, only a neuromatrix; Part 6d: History of Pain: Final takedown Part 6e: Pattern theories in the history of pain Part 6f: Evaluation of pain theories Part 6g: History of Pain, the cautionary tale. Part 6h: Gate Control Theory.

Part 7: Gate control theory has stood the test of time: Patrick David Wall;  Part 7bGate control: "The theory was a leap of faith but it was right!"

Part 8: Beyond the gate: Self as mayor Part 8b: 3-ring circus of self Part 8c: Getting objective about subjectivity

Part 9: Phantom pain - in the brain! Part 9b: Dawn of the Neuromatrix model Part 9cNeuromatrix: MORE than just spinal projection areas in thalamus and cortex Part 9d: More about phantom body pain in paraplegics

Part 10: "We don't need a body to feel a body." Part 10b: Conclusion1: The brain generates its own experience of being in a body Part 10c:Conclusion 2: Your brain, not your body, tells you what you're feeling Part 10dConclusion 3: The brain's sense of "Self" can INclude missing parts, or EXclude actual parts, of the biological body Part 10eThe neural network that both comprises and moves "Self" is (only)modified by sensory experience

Part 11We need a new conceptual brain model! Part 11b: Intro to a new conceptual nervous system Part 11c: Older brain models just don't cut it Part 11d: The NEW brain model!

Part 12: Action! 12b: Examining the motor system, first pass. 12c: Motor output and nervous systems - where they EACH came from Part 12d... deeper and deeper into basal ganglia Part 12e: Still awfully deep in basal ganglia Part 12f: Surfacing out of basal ganglia Part 12gThe Action-Neuromatrix 

Part 13: Pain and Neuroplasticity Part 13b: Managing neuroplasticity

Part 14: Side trip out to the periphery! Part 14b: Prevention of pain neurotags is WAY easier than cure Part 14cPW Nathan was an interesting pain researcher  Part 14dBrain glia are from neuroectoderm and PNS glia are from neural crest Part 14e: The stars in our headsPart 14f: Gleeful about glia Part 14g: ERKs and MAPKs and pain Part 14h: glia-fication of nociceptive input 14i: molecular mediators large and small Part 14j: Neurons, calling glia (over, do you read?) Part 14k: Glia calling glia, over. Do you read? Part 14l: satellite cell and neuron cell body interactions, and we're outta here!

Part 15: Prevention of neurobiological hoarding behaviour by dorsal horn and DRG glia is easier than clutter-busting after the fact

Part 16: Apples are to fruit as cows are to animals as nociceptive input is to pain

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