Pain in the peripheral nervous system

[misgfool]

To my (limited) understanding, the peripheral nervous system sends messages of pain in the form of electrical impulses to the brains. But what's the difference between signals of extreme pain and mild pain/touch?

[Monique]

Well, what is the difference between looking at a dim light and an ultra-bright light. The latter will make you squint your eyes: it is a matter of the amount of stimulation. You have different receptors for different types of information: the nocireceptor senses injury and is thus responsible for feeling pain, you also have mechano- and thermoreceptors.

The introduction of this review is interesting (about the difference between non-painful and painful sensory stimuli): Peripheral pain mechanisms (http://linkinghub.elsevier.com/retrieve/pii/S0959-4388(97)80028-1).

[misgfool]

Well, what is the difference between looking at a dim light and an ultra-bright light. The latter will make you squint your eyes: it is a matter of the amount of stimulation. You have different receptors for different types of information: the nocireceptor senses injury and is thus responsible for feeling pain, you also have mechano- and thermoreceptors.

I'm interested in the actual signal that travels, like it's waveform, amplitude, phase etc? So that brains know that this is serious pain, output a mighty roar from mouth. :smile:

The introduction of this review is interesting (about the difference between non-painful and painful sensory stimuli): Peripheral pain mechanisms (http://linkinghub.elsevier.com/retrieve/pii/S0959-4388(97)80028-1).

I was looking for a bit (100%) cheaper article.

[Monique]

I'm interested in the actual signal that travels, like it's waveform, amplitude, phase etc? So that brains know that this is serious pain, output a mighty roar from mouth. :smile: First, there is a threshold that needs to be crossed before the nocireceptor starts to fire a signal. When there is sufficient stimulus, an action potential is created: the membrane of the neuron depolarizes (the voltage increases), the voltage peaks after which you get a hyperpolarization and a refractory period. The action potential spreads to the adjacent membrane, so that it can travel along the axon. The refractory period ensures that the signal can only travel in one direction, once the membrane has recovered it can fire again. The neuron can either be slightly excited giving a sparse signal, or strongly excited giving a continuous signal. I hope that addresses your question.

[zoobyshoe]

I'm interested in the actual signal that travels, like it's waveform, amplitude, phase etc? So that brains know that this is serious pain, output a mighty roar from mouth. :smile:



I was looking for a bit (100%) cheaper article.
Wikipedia is free:

The conduction of nerve impulses is an example of an all-or-none response. In other words, if a neuron responds at all, then it must respond completely. The greater the intensity of stimulation does not produce a stronger signal but can produce more impulses per second. There are different types of receptor response to stimulus, slowly adapting or tonic receptors respond to steady stimulus and produce a steady rate of firing. These tonic receptors most often respond to increased intensity of stimulus by increasing their firing frequency, usually as a power function of stimulus plotted against impulses per second. This can be likened to an intrinsic property of light where to get greater intensity of a specific frequency (color) there has to be more photons, as the photons can't become "stronger" for a specific frequency.

http://en.wikipedia.org/wiki/Neuron

[somasimple]

Nociception isn't pain. Nociception is the message that is sent to brain.
Pain (http://www.iasp-pain.org/AM/Template.cfm?Section=General_Resource_Links&Template=/CM/HTMLDisplay.cfm&ContentID=3058#Pain)is created only by brain.

Pain
An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. Note: The inability to communicate verbally does not negate the possibility that an individual is experiencing pain and is in need of appropriate pain-relieving treatment. Pain is always subjective. Each individual learns the application of the word through experiences related to injury in early life. Biologists recognize that those stimuli which cause pain are liable to damage tissue. Accordingly, pain is that experience we associate with actual or potential tissue damage. It is unquestionably a sensation in a part or parts of the body, but it is also always unpleasant and therefore also an emotional experience. Experiences which resemble pain but are not unpleasant, e.g., pricking, should not be called pain. Unpleasant abnormal experiences (dysesthesias) may also be pain but are not necessarily so because, subjectively, they may not have the usual sensory qualities of pain.

Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons. There is usually no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain. This definition avoids tying pain to the stimulus. Activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state, even though we may well appreciate that pain most often has a proximate physical cause.

[zoobyshoe]

Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons.


One cause of a huge variety of symptoms, including pain, that appear to have no pathophysiological cause, and which can be misdiagnosed as psychological, is Simple Partial Seizures:

# Symptoms associated with seizures from the postcentral gyrus include tingling, numbness, pain, heat, cold, agnosia, phantom sensations, or sensations of movement.
# Abdominal pain usually originates from the temporal lobe, and genital pain from the mesial parietal sensory cortex.

http://emedicine.medscape.com/article/1184384-overview

Many Simple Partial Seizures are restricted to such small and/or deep portions of the brain that they aren't picked up by surface electrodes in an EEG, (which makes their misdiagnosis as psychological even more likely):

http://www.ncbi.nlm.nih.gov/pubmed/3137487


From Somasimple's quote:
There is usually no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain. This definition avoids tying pain to the stimulus. Activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state, even though we may well appreciate that pain most often has a proximate physical cause.

Therefore: I don't agree with the characterization of pain as a "psychological" experience in all cases. It would, by this author's logic, be accurate to say that our experience of heat and cold are always "psychological" as well. At the same time it is accurate to observe there is no dedicated "pain" signal; that a neutral signal's conversion to a perception of pain takes place in the brain, that conversion is a neurological, and not a psychological, event. The same neurological event can be triggered by means other than the normal stimulus (eg: simple partial seizure, trigeminal neuralgia), without it becoming a psychological event. The word "psychological" conotes emotional interpretation in the context of personal history.

[misgfool]

First, there is a threshold that needs to be crossed before the nocireceptor starts to fire a signal. When there is sufficient stimulus, an action potential is created: the membrane of the neuron depolarizes (the voltage increases), the voltage peaks after which you get a hyperpolarization and a refractory period. The action potential spreads to the adjacent membrane, so that it can travel along the axon. The refractory period ensures that the signal can only travel in one direction, once the membrane has recovered it can fire again. The neuron can either be slightly excited giving a sparse signal, or strongly excited giving a continuous signal. I hope that addresses your question.

Ok, so the voltage (amplitude) of the signal is higher for extreme pain than for slight pain. Now the second question is that, why is it so hard to reconnect nerves when they have been cut? If they only acts as conductors for electricity, why isn't it possible to reconnect them with any conducting material?

[zoobyshoe]

Ok, so the voltage (amplitude) of the signal is higher for extreme pain than for slight pain. Now the second question is that, why is it so hard to reconnect nerves when they have been cut? If they only acts as conductors for electricity, why isn't it possible to reconnect them with any conducting material?
Axons don't work the same way as a conductor in an electric circuit. How much do you know about conventional electric circuits? It's hard to explain the difference without knowing how much you already know about either.

[misgfool]

Axons don't work the same way as a conductor in an electric circuit. How much do you know about conventional electric circuits? It's hard to explain the difference without knowing how much you already know about either.

I know a lot (almost all) about electric circuits, but very little of axons.

[Monique]

Ok, so the voltage (amplitude) of the signal is higher for extreme pain than for slight pain. No, it is the number of pulses that are generated by the neuron.

[turbo]

Nociception isn't pain. Nociception is the message that is sent to brain.

Pain is created only by brain.I can attest to this. Years ago, I suffered a mild stroke due to some prescription medication that sent my heart into atrial fibrillation. A small clot made its way to my brain-stem and the damage caused me to lose temperature sensation in my right leg AND to cause a constant severe burning sensation in my right foot. My neurologist said that even if my right leg was amputated due to some severe injury or disease, I would still experience this pain for the rest of my life. Neuropathic pain is not fun at all - it can't be lessened with pain-killers, etc.

[misgfool]

I can attest to this. Years ago, I suffered a mild stroke due to some prescription medication that sent my heart into atrial fibrillation. A small clot made its way to my brain-stem and the damage caused me to lose temperature sensation in my right leg AND to cause a constant severe burning sensation in my right foot. My neurologist said that even if my right leg was amputated due to some severe injury or disease, I would still experience this pain for the rest of my life. Neuropathic pain is not fun at all - it can't be lessened with pain-killers, etc.

What I was thinking, that is if have understood this nerve thing correctly, was to cut a nervous pathway and put a microchip in between two axons to some point where the nerves are bundled (like shoulder etc.). The chip wouldn't have to be physically embedded to the tissue, but conductors to the axon membranes would be needed. Then program the chip so, that it would filter out extreme pain coming from the arm (i.e. reduce the amount of pulses heading to brains) without the need for brain dissolving medication. It would be a very simple to make such a chip and when mass produced the price would easily be less that $10. Best part is that it could be programmed in any way the patient wants. This was obviously a simplified case, since there must be a few of those pathways, but the principle should apply.

[somasimple]

Nerves use ions that have electric consequences but a microchip is purely electric, far from the functioning of a nerve that have many ways to change its behavior.
And pain is not an incoming stimulus but a brain response to noxious (or considered as) stimulus.

[misgfool]

Nerves use ions that have electric consequences but a microchip is purely electric, far from the functioning of a nerve that have many ways to change its behavior.
And pain is not an incoming stimulus but a brain response to noxious (or considered as) stimulus.

If nerves have electric consequences, they can be integrated with electric circuits.

However, I don't quite understand that stimulus thing. How can the brains know if you hide your hand and someone/thing touches one finger? There has to be some kind of sensory input coming to brains. All one has to do is to identify which signal is noxious and filter it out.

[zoobyshoe]

If nerves have electric consequences, they can be integrated with electric circuits.
The point is that you can't simply splice any old conductor into an axon.

I'm assuming you understand ions and cations. The electrical activity of nerves and neurons is based on actual physical motion of these, especially cations, rather than the EMF of conventional electricity based on electrons.

To understand this, you need to take some time to read up on the basics of action potentials. Maybe Monique ot Soma know a good site.

[misgfool]

The point is that you can't simply splice any old conductor into an axon.

How about a new one? :smile: My purpose is not to make an axon, only something that can interface with axons.

I'm assuming you understand ions and cations. The electrical activity of nerves and neurons is based on actual physical motion of these, especially cations, rather than the EMF of conventional electricity based on electrons.

There is only one (known) kind of electricity in the universe. It involves the presence and flow of electric charge. There is no conventional and unconventional electricity. It's either electricity or it is something totally different.

Apparently ion is a general category for atoms or molecules that have gained or lost electron(s). Ions have two subcategories: Anion which has more electrons than protons and cation which has less electrons than protons. Hence both of these have an electric charge of different polarity and are well in the realm of what you call conventional electricity.

It involves measurements of voltage change or electric current on a wide variety of scales from single ion channel proteins to whole organs like the heart.

Now looking at Wikipedia, you can see a picture of membrane voltage. I can't find any explanation why it would be different from other kinds of voltage measurements. For example look at the voltage clamp picture in Electrophysiology -article.

http://en.wikipedia.org/wiki/Action_potential
http://en.wikipedia.org/wiki/Electrophysiology

[zoobyshoe]

There is only one (known) kind of electricity in the universe. It involves the presence and flow of electric charge. There is no conventional and unconventional electricity. It's either electricity or it is something totally different.
If I said a Stirling engine is not the conventional heat engine powered by exploding gases, would you object saying "There's only one (known) kind of heat in the universe. It's either a heat engine or it is something totally different. There is no conventional and unconventional heat."

[misgfool]

If I said a Stirling engine is not the conventional heat engine powered by exploding gases, would you object saying "There's only one (known) kind of heat in the universe. It's either a heat engine or it is something totally different. There is no conventional and unconventional heat."

I can't see the analogy. Also that example is incomprehensible and silly. No need to be offended. I was just stating a fact. Let's try to stick in the topic.

[Monique]

There has to be some kind of sensory input coming to brains. All one has to do is to identify which signal is noxious and filter it out. I've heard of conditions where a physician will cut a nerve that is causing a noxious stimulus, but this is not an easy thing to do. What exactly is your idea about the application of the concept?

[zoobyshoe]

I can't see the analogy. Also that example is incomprehensible and silly. No need to be offended. I was just stating a fact. Let's try to stick in the topic.
It's sounding more like you want to be a pain in the peripheral nervous system rather than alleviating it.:biggrin:

[misgfool]

I've heard of conditions where a physician will cut a nerve that is causing a noxious stimulus, but this is not an easy thing to do. What exactly is your idea about the application of the concept?

I'm fairly good in what I choose to do. Really, I am. But I came up with this idea about 6 hours ago in a bus (while watching a charming young lady who had green eyes by the way), so you are demanding quite a lot at this point of the (hobby) project. I'm good, but not quite that good. However, while technical issues are very easy to solve, the biological side is still bit of a question mark. And that's where I could use some help.

It's sounding more like you want to be a pain in the peripheral nervous system rather than alleviating it.

All the more reason for you to focus in developing this chip, so that you can program it to filter the pain I'm causing. :smile:

[turbo]

All the more reason for you to focus in developing this chip, so that you can program it to filter the pain I'm causing. :smile:How do you dial back pain safely? If your hardware solution makes extreme pain tolerable, how is the implantee going to be able to distinguish between pain that indicates that a mild amount of tissue damage may be occurring, and a (damped) sensation that on examination reveals that some really extreme damage is occurring? Doctors already have tools at their disposal (including narcotics) to deal with chronic pain, though as I posted above, their tools to deal with neuropathic-induced pain are limited and sufferers pretty much have to learn to live with it.

Pain is not pleasant, but it has real survival value.

[somasimple]

I've heard of conditions where a physician will cut a nerve that is causing a noxious stimulus, but this is not an easy thing to do. What exactly is your idea about the application of the concept?
And they stopped because they can't cut the brain.

[somasimple]

Pain is part of a security system. Without pain no life. Patient who do not feel pain have a short life time (<20 yrears).

[somasimple]

Therefore: I don't agree with the characterization of pain as a "psychological" experience in all cases. It would, by this author's logic, be accurate to say that our experience of heat and cold are always "psychological" as well. At the same time it is accurate to observe there is no dedicated "pain" signal; that a neutral signal's conversion to a perception of pain takes place in the brain, that conversion is a neurological, and not a psychological, event. The same neurological event can be triggered by means other than the normal stimulus (eg: simple partial seizure, trigeminal neuralgia), without it becoming a psychological event. The word "psychological" conotes emotional interpretation in the context of personal history.
See Ramachanfran and phantom limb pain.
http://en.wikipedia.org/wiki/Phantom_limb
Psychology is the result of neurons activation: a physical process.

[somasimple]

There is only one (known) kind of electricity in the universe. It involves the presence and flow of electric charge. There is no conventional and unconventional electricity. It's either electricity or it is something totally different.

A ion that is moving creates an electric field that is effectively electricity but where is the circuit?
Conventional electronic chips need electric circuits. A neuron has no dedicated wires or electric circuit. No circuit lets an useless electric field.
And a chip needs energy.

[somasimple]

And a last and quite definite problem is that you can't cut an axon without killing it.

[Monique]

And they stopped because they can't cut the brain. What's this problem you have with the brain? If a neuron is misfiring and thus causing trouble, you need to tame it. The brain adds another level of complexity and it certainly can cause problems, but that does not mean you can completely ignore the effect of the neuron itself.

[somasimple]

Where do go neurons? Where are they connected?
I have no problem with brain. Brain is the masterpiece of pain. Without brain no pain.

[misgfool]

Pain is not pleasant, but it has real survival value.

Yes, but if it is chronic and severe, it doesn't really help. I would also like to reduce the medical payload people get, since drugs often have undesirable side effects. Unfortunately, the chip wouldn't help you.

[misgfool]

A ion that is moving creates an electric field that is effectively electricity but where is the circuit?
Conventional electronic chips need electric circuits. A neuron has no dedicated wires or electric circuit. No circuit lets an useless electric field.

I already solved this problem. I'm not going to go into details.

And a chip needs energy.

Yes.

And a last and quite definite problem is that you can't cut an axon without killing it.

I wouldn't cut an axon, just separate two of them from each others.

[somasimple]

I wouldn't cut an axon, just separate two of them from each others.
it doesn't mean anything, sorry.
An axon is a single piece you can't separate from the soma.

[misgfool]

it doesn't mean anything, sorry.
An axon is a single piece you can't separate from the soma.

Ok, thanks all for help.

[somasimple]

A nerve is a bundle that contains thousands and thousand axons. Of course, they aren't labeled so you do not know which are transmitting nociception.
http://en.wikipedia.org/wiki/Neuron

[zoobyshoe]

See Ramachanfran and phantom limb pain.
http://en.wikipedia.org/wiki/Phantom_limb
I've read about Ramachandran's work in phantom limbs a couple times before. It is a phenomenon of the brain, just as you say, but not a psychological one. I think we're both in agreement about what is happening, it's the term psychological I object to. It could be that in French this word has a different connotation.

"psy·chol·o·gy

1: the science of mind and behavior2 a: the mental or behavioral characteristics of an individual or group b: the study of mind and behavior in relation to a particular field of knowledge or activity3: a theory or system of psychology <Freudian psychology> <the psychology of Jung>"
http://www.merriam-webster.com/dictionary/psychology

Psychology is about the programming and programs, so to speak, and not the hardware. It's about what is called "mind"; about the way people think and behave. If a person were hypnotized to experience physical pain at the sight of a book, then that is a psychological event: it's purely the result of programming.

That is a consideration distinct from the physical mechanisms whereby the brain creates sensory experiences from stimuli. Phantom limb pain is the result of the mechanism, the hardware being forced to operate in the absence of normal stimuli. When the neurons have no direct input from the limbs they start accepting and processing input from the surrounding neurons and processing it as if it were from the limbs. That's a neurological event. A psychological explanation, on the other hand, would be, for example, to assert that the person is grief stricken over having lost a limb and reacts by becoming psychotic enough to convince themselves that the limb is still there.

That's the reason I object to his use of the word "psychological". If we define neurological events as psychological then people with Multiple Sclerosis and even Traumatic Brain Injuries, should be sent to psychologists and psychiatrists, and we can do away with neurologists.

[turbo]

I've read about Ramachandran's work in phantom limbs a couple times before. It is a phenomenon of the brain, just as you say, but not a psychological one. I think we're both in agreement about what is happening, it's the term psychological I object to. True. My constant pain (burning right foot) is not some psychological problem. It is entirely physiological, as pointed out to me by my neurologist (a lovely German woman). She showed me the small region in my brain-stem that was damaged by the stroke, using MRI images. That region handles bi-lateral neural paths, so while I lost temperature sensation in the right leg from the hip down (and got this relentless roasting sensation in my right foot) I also lost a lot of joint-position feedback from the left leg. I learned to walk again in a few days, but uneven ground still gives me fits, especially if I am not perfectly upright. Nothing psychological about any of it, or I'd have had my brain shrunk long ago.

[zoobyshoe]

True. My constant pain (burning right foot) is not some psychological problem. It is entirely physiological, as pointed out to me by my neurologist (a lovely German woman). She showed me the small region in my brain-stem that was damaged by the stroke, using MRI images. That region handles bi-lateral neural paths, so while I lost temperature sensation in the right leg from the hip down (and got this relentless roasting sensation in my right foot) I also lost a lot of joint-position feedback from the left leg. I learned to walk again in a few days, but uneven ground still gives me fits, especially if I am not perfectly upright. Nothing psychological about any of it, or I'd have had my brain shrunk long ago.
Exactly. "Psychological" connotes "psychosomatic", which very erroneously characterizes the sufferer's problem as one of mental illness.

----------

I hope you don't mind my saying so, but your symptoms are very interesting. It just underscores how complex the architecture is.

[turbo]

Exactly. "Psychological" connotes "psychosomatic", which very erroneously characterizes the sufferer's problem as one of mental illness.

----------

I hope you don't mind my saying so, but your symptoms are very interesting. It just underscores how complex the architecture is.I don't mind. I would like people to consider that our soldiers coming back from wars with wounds can be afflicted with many of these same symptoms. Phantom pain in amputated limbs (perhaps debilitating pain) loss of many types of sensation, etc, can result from the traumatic injuries these people suffered in their service. I had a tiny clot migrate to my brain-stem and kill some cells. Some of these people have suffered severe physical injuries, and the hardest ones to diagnose after the fact may be hidden brain injuries.

[turbo]

To follow up, our returning soldiers can be outwardly "whole" while suffering from pain that is very real, and that cannot be treated with pain-killers because it originates in their brains. They can never escape it, and well-meaning but inadequately-trained VA doctors can set them on treatment paths that result in addiction, frustration, self-destructive behaviors, and worse.

[somasimple]

I've read about Ramachandran's work in phantom limbs a couple times before. It is a phenomenon of the brain, just as you say, but not a psychological one. I think we're both in agreement about what is happening, it's the term psychological I object to. It could be that in French this word has a different connotation.

"psy·chol·o·gy

1: the science of mind and behavior2 a: the mental or behavioral characteristics of an individual or group b: the study of mind and behavior in relation to a particular field of knowledge or activity3: a theory or system of psychology <Freudian psychology> <the psychology of Jung>"
http://www.merriam-webster.com/dictionary/psychology

Psychology is about the programming and programs, so to speak, and not the hardware. It's about what is called "mind"; about the way people think and behave. If a person were hypnotized to experience physical pain at the sight of a book, then that is a psychological event: it's purely the result of programming.


Where lives the mind? Where is created behaviors?
You may contest that it is situated elsewhere than the brain. It is not my concern but as the scientific mind you may bring some proof that it is not the result of neurons network activation. A neurons network is purely physical and their activation create programs: something that is purely material and hardwired by physical synapses.

The connotation of psychosomatic and psychological that you brought is not scientific at all. Freund and all are not sciences and actually criticized by neuro-scientists. See Damasio...

She showed me the small region in my brain-stem that was damaged by the stroke, using MRI images.
Did I said brain? :confused:

I agree there is a problem of term but all illness have a psychological component because brain reacts every time the body is threatened. I fell sick or It hurts are already the result of brain activation.

Read this excellent book: Explain pain (http://www.amazon.com/Explain-Pain-David-Butler/dp/097509100X/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1232777555&sr=8-1)

[somasimple]

Exactly. "Psychological" connotes "psychosomatic", which very erroneously characterizes the sufferer's problem as one of mental illness.


A mental illness? Do you mean a brain disorder? or a physical problem that occurs between some neurons located in brain? :confused:

[somasimple]

A favorite of mine from this book:
ALL PAIN IS REAL!

[Math Is Hard]

Where lives the mind? Where is created behaviors?
You may contest that it is situated elsewhere than the brain. It is not my concern but as the scientific mind you may bring some proof that it is not the result of neurons network activation. A neurons network is purely physical and their activation create programs: something that is purely material and hardwired by physical synapses.

The connotation of psychosomatic and psychological that you brought is not scientific at all. Freund and all are not sciences and actually criticized by neuro-scientists. See Damasio...


Did I said brain? :confused:

I agree there is a problem of term but all illness have a psychological component because brain reacts every time the body is threatened. I fell sick or It hurts are already the result of brain activation.

Read this excellent book: Explain pain (http://www.amazon.com/Explain-Pain-David-Butler/dp/097509100X/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1232777555&sr=8-1)


Do you consider yourself a Behaviorist, somasimple?

http://en.wikipedia.org/wiki/Behaviourism

I'm not clear on your stance.

[Mashes]

I'm interested in the actual signal that travels, like it's waveform, amplitude, phase etc? So that brains know that this is serious pain, output a mighty roar from mouth. :smile:



I was looking for a bit (100%) cheaper article.


I took anatomy and physiology I last semester and aced it. I think what you may be asking is the signal from sensory to brain and back to the motor unit that determines what's going on. You have sensory receptors in the skin, pacinian corpuscle, which adapts to the environment if it's light pressure or minor change in temperature. That's why when you have cloths on you tend to forget it's there. When you put your hand on the stove, an action potential arises from the sensory nerve that then travels to the spine, were an ascending tract, that has a name but I totally forgot it, shoots it up to the brain. Then the nerve comes in contact with its terminal were a chemical reaction takes place that transfers the action potential from the sensory nerve to an integrative nerve in the brain (Could explain this in more detail, just ask, i'll crack open the textbooks). The integrative nerve is the choice maker in this scenario. The integrative
nerve decides a course of action and the same chemical reaction that occurred at the sensory/integrative synapses happens here. The chemical reaction creates an action potential for the motor neuron to move your hand from the stove and let out that mighty roar, or in my case that mighty whimper.

So heres the summery- If you think of it a highway it becomes stupid easy.
1) Hand on stove, sensory nerve creates action potential
2) Action potential continues through the PNS until it reaches the CNS ( spine and brain )
3) Ascending tract launches sensory impulse to brain.
4) Sensory impulse transfers from sensory to integrative
5) Integrative to motor neuron
6) Epic scream and removal of hand from stove..hopefully.

If anyone notices something I missed, or said incorrectly, do correct me. I did this from memory and I'm on winter break so I'm rusty and this is great practice.

[somasimple]

Do you consider yourself a Behaviorist, somasimple?

http://en.wikipedia.org/wiki/Behaviourism

I'm not clear on your stance.

I do not think so.
I'm just a physical therapist (PT) and my level of expertise is pain and behaviors carried by pain.
http://www.somasimple.com/forums/

[somasimple]

So heres the summery- If you think of it a highway it becomes stupid easy.
1) Hand on stove, sensory nerve creates action potential
2) Action potential continues through the PNS until it reaches the CNS ( spine and brain )
3) Ascending tract launches sensory impulse to brain.
4) Sensory impulse transfers from sensory to integrative
5) Integrative to motor neuron
6) Epic scream and removal of hand from stove..hopefully.

If anyone notices something I missed, or said incorrectly, do correct me. I did this from memory and I'm on winter break so I'm rusty and this is great practice.

I can't describe this sequence for an amputee who has this right missing foot that is itching like hell. You're missing something.

[Mashes]

Oh and to the posters of the post prior to mine, I read this book called My Stroke Of Insight by Jill Bolte Taylor, Neuroanatomist. She had a stroke and while having the stroke she studied her behavior and physical state. Really gripping book with a lot to offer. Anyways, the end of the book is filled with brain and CNS facts about behavior and psychology. There was one page I wish I could quote but I lent my communications professor my copy of the book and the dude never returned it. It was about how physiological reactions to anger only last 90 seconds and after that it's our choice on how we want to feel. Heres a video about her book and her experiences.

http://www.youtube.com/watch?v=UyyjU8fzEYU

[Mashes]

I can't describe this sequence for an amputee who has this right missing foot that is itching like hell. You're missing something.

The post was intended for misgool and was basic API. I hit all the points he wanted to know. As for what you're looking for, I have no idea why this would happen. Part of psychological grieving? People remember certain sensations, perhaps stronger then others? Couldn't tell you really

[Math Is Hard]

I can't describe this sequence for an amputee who has this right missing foot that is itching like hell. You're missing something.

Do you have any effective therapies for that? A long time ago I read about a remedy of letting the person scratch the opposite (intact) foot in front of a mirror and that seemed to help. I can't remember how they rigged it to create a precise illusion that the itching foot was being scratched.

[somasimple]

The post was intended for misgool and was basic API. I hit all the points he wanted to know. As for what you're looking for, I have no idea why this would happen. Part of psychological grieving? People remember certain sensations, perhaps stronger then others? Couldn't tell you really
Part of psychological grieving? no.
People remember certain sensations, perhaps stronger then others? probably.

Mirror therapy gives good results:
http://content.nejm.org/cgi/content/full/357/21/2206
http://www.mirrorboxtherapy.com/

[Mashes]

Part of psychological grieving? no.
People remember certain sensations, perhaps stronger then others? probably.

Mirror therapy gives good results:
http://content.nejm.org/cgi/content/full/357/21/2206

You don't think it has anything to do with psychology? Drug addictions start as a psychological phenomena which in turn becomes a physiological phenomena. Withdrawal for instances can kill a patient, and it was something the patient developed habitually.

Also part of the grieving process is denial, could having pains in a part of your body that aren't even there anymore be considered a physiological form of denial?

[somasimple]

You don't think it has anything to do with psychology? Drug addictions start as a psychological phenomena which in turn becomes a physiological phenomena. Withdrawal for instances can kill a patient, and it was something the patient developed habitually.

Also part of the grieving process is denial, could having pains in a part of your body that aren't even there anymore be considered a physiological form of denial?
You do not read what I'm writing: I'm not interested by psychology. Mirror box therapy acts on brain and brain is an assembly of neurons. Brain is a physical organ.
Brain is complex and it is sure that Medicine says it is psychosomatic when the treatment fails. But Medicine says this because it doesn't understand the patient's complaint and has nothing to offer.

[somasimple]

Drug addictions start as a psychological phenomena
No. Addiction is purely physical: neurons want something (a chemical product) in urge. This urge creates behaviors that looks abnormal for others.

[Mashes]

You do not read what I'm writing: I'm not interested by psychology. Mirror box therapy acts on brain and brain is an assembly of neurons. Brain is a physical organ.
Brain is complex and it is sure that Medicine says it is psychosomatic when the treatment fails. But Medicine says this because it doesn't understand the patient's complaint and has nothing to offer.

Well if you know what you're talking about, then WHAT exactly are you interested in? You seem to have you stuff all together and you seem to understand, besides, my original post was intended for Misgool

Any who, I hope what I said made sense to you Misgool. You should take AP I and II. They really put things in perspective and unravel the mysteries of human anatomy.

[Mashes]

No. Addiction is purely physical: neurons want something (a chemical product) in urge. This urge creates behaviors that looks abnormal for others.

Do neurons want the chemical product? or does the motor unit? Also, some people overcome addictions with will power, which is psycological.

[somasimple]

Well if you know what you're talking about, then WHAT exactly are you interested in? You seem to have you stuff all together and you seem to understand, besides, my original post was intended for Misgool

Any who, I hope what I said made sense to you Misgool. You should take AP I and II. They really put things in perspective and unravel the mysteries of human anatomy.
My posts have the same intention: Replying to a question. The answer is more complex than expected and pain can't be cured by systems that act on peripheral nervous system. It had been tested and used since decades; It is called TENS: Transcutaneous Electrical Nerve Stimulation.

[somasimple]

Do neurons want the chemical product? or does the motor unit? Also, some people overcome addictions with will power, which is psycological.
What is a motor unit? a neuron connected to a myofibrill!
Power, emotions, thoughts are physical because wa are able to see the neural activation with PetSCAN and fMRI and Magneto Encephalography.

[Mashes]

My posts have the same intention: Replying to a question. The answer is more complex than expected and pain can't be cured by systems that act on peripheral nervous system. It had been tested and used since decades; It is called TENS: Transcutaneous Electrical Nerve Stimulation.

What about systems operating on the vagus nerve? Is the vagus nerve CNS or PNS?

[somasimple]

Vagus nerve belongs to CNS but CNS contains ANS that is Autonomic Nervous System. The ANS is the real subconscious nervous system. It may act against your will (and it does).
Vagus nerve has little to do with pain.
Vagus nerve is also designated as the X cranial nerve.

[Math Is Hard]

Mirror therapy gives good results:
http://content.nejm.org/cgi/content/full/357/21/2206
http://www.mirrorboxtherapy.com/


Thanks, soma. That's what I was thinking of.

[Mashes]

Vagus nerve belongs to CNS but CNS contain ANS that is Autonomic Nervous System. The ANS is the real subconscious nervous system. It may act against your will (and it does).
Vagus nerve has little to do with pain.

In what cases does the Vagus nerve have to do with pain, besides parasympathetic nausea and stomach cramp reactions?

[somasimple]

In what cases does the Vagus nerve have to do with pain, besides parasympathetic nausea and stomach cramp reactions?
None, IMHO.
http://en.wikipedia.org/wiki/Vagus_nerve

[zoobyshoe]

The connotation of psychosomatic and psychological that you brought is not scientific at all. Freund and all are not sciences and actually criticized by neuro-scientists. See Damasio...
This is pretty much my point. You can't separate psychology from "Freud and all". I am not the one giving that word that connotation. The definition I offered is from a well respected dictionary.

I am sure that there is a better term to replace "psychological" that comes from Neuro-Science. It might be "experiential" .

Hence: "All experiential pain is real pain." Meaning: When a person has the experience of pain it should be considered real pain.

The "psychological" interpretation of pain draws the opposite conclusion: "It's all in your mind. It's not real. It will go away if you talk to a therapist or simply stop thinking about it."

[zoobyshoe]

Also part of the grieving process is denial, could having pains in a part of your body that aren't even there anymore be considered a physiological form of denial?
As Ramachandran and his colleages demonstrated it is the result of the neurons which would usually receive stimuli from the limbs receiving it from the surrounding neurons instead. For example, the thumb and parts of the face are located right next to each other on the sensory homunculus. Touching the cheek of a person with no hand will give them the sensation the missing thumb is being touched. Authentic stimuli is bleeding over to the adjacent location, as it were. That adjacent location, it is reasoned, is vulnerable to this because it is starved of the stimuli it would normally be receiving.

There must certainly be a purely psychological component: it must take a long time to overcome the expectation of having a limb where it has always been. However, as in the case of Turbo, these phantom sensations can occur exclusively from insult to the brain with all limbs intact and undamaged.

[somasimple]

This is pretty much my point. You can't separate psychology from "Freud and all". I am not the one giving that word that connotation. The definition I offered is from a well respected dictionary.

I am sure that there is a better term to replace "psychological" that comes from Neuro-Science. It might be "experiential" .

Hence: "All experiential pain is real pain." Meaning: When a person has the experience of pain it should be considered real pain.

The "psychological" interpretation of pain draws the opposite conclusion: "It's all in your mind. It's not real. It will go away if you talk to a therapist or simply stop thinking about it."

In our daily practice we see patients who experience pain without any body damage: My low back hurts since I lost my job! Is he a liar? Not at all! His body hurts.
Comments?
http://www.somasimple.com/forums/showthread.php?t=4944

As Ramachandran and his colleages demonstrated it is the result of the neurons which would usually receive stimuli from the limbs receiving it from the surrounding neurons instead. For example, the thumb and parts of the face are located right next to each other on the sensory homunculus. Touching the cheek of a person with no hand will give them the sensation the missing thumb is being touched. Authentic stimuli is bleeding over to the adjacent location, as it were. That adjacent location, it is reasoned, is vulnerable to this because it is starved of the stimuli it would normally be receiving.


There must certainly be a purely psychological component: it must take a long time to overcome the expectation of having a limb where it has always been. However, as in the case of Turbo, these phantom sensations can occur exclusively from insult to the brain with all limbs intact and undamaged.
Many babies were born without limbs and unfortunately their missing limbs hurt.
There must certainly be a purely psychological component? In utero?

[zoobyshoe]

In our daily practice we see patients who experience pain without any body damage: My low back hurts since I lost my job! Is he a liar? Not at all! His body hurts.
Comments?
Are you stipulating that it's psychosomatic?
Many babies were born without limbs and unfortunately their missing limbs hurt.
There must certainly be a purely psychological component? In utero?
Despite being born without limbs they were born with places on their sensory strip to process stimuli from limbs. All the same neurological causes of phantom pains in amputees exist in this case.

However, since they never had limbs they don't experience the purely psychological upset of missing something they used to have. I don't miss my Mercedes, because I never had a Mercedes.

[somasimple]

Are you stipulating that it's psychosomatic?

Did I? You're making distinctions between pains. I do not.
This man experiences pain. His pain is real. His pain is located in the lower back.
I may consider only his pain and I'll fail to help him.
I'm considering a man who lost his job and he is suffering from that.
I will communicate with him (brain) or with his body (brain) and perhaps it will help.

Any event may have painful consequences.

[turbo]

Remember the "neural induction" device used by the witch in Dune to test the duke's son? It induced a feeling of burning in his hand so real that he should have withdrawn his hand from the box in self-preservation. His refusal to do so was "proof" that he was a superior being.

I fear that sadists in the medical field will find ways to induce pain this way, and sell it to governments so they can torture people with no detectable tissue damage. Far-fetched? Don't think so.

[zoobyshoe]

You're making distinctions between pains.
No. Between causes.

[somasimple]

No. Between causes.
Does that change the result: Pain?

[Monique]

Somasimple, I think it should be very clear that the cause of the pain should dictate the type of treatment. It seems to be that you are saying that pain is like a dream that is imagined by the brain and that if you 'wake' someone that the pain will be gone. Pain is something physically real. You don't tell a seeing person to ignore his sight and expect him to go blind.

[somasimple]

Somasimple, I think it should be very clear that the cause of the pain should dictate the type of treatment. It seems to be that you are saying that pain is like a dream that is imagined by the brain and that if you 'wake' someone that the pain will be gone. Pain is something physically real. You don't tell a seeing person to ignore his sight and expect him to go blind.

A favorite of mine from this book:
ALL PAIN IS REAL!

It seems that I didn't say something like that.
And you may search something about pain distraction (http://www.ampainsoc.org/pub/bulletin/spr05/inno1.htm).

Virtual Reality analgesia is not limited to burn patients, however. Immersive VR distraction is being used to treat a growing number of painful procedures:

Reality? Not a bit but brain doesn't care. :redface:

[Proton Soup]

having been woke up from my sleep recently with sinus pain, it seems awfully real to me, dreaming or not.

and FWIW, pain receptors can cause real physiological symptoms whether you feel the pain in your brain or not. let's say you're a paraplegic, and you want to cheat at wheelchair racing. one thing that might be done is to put tacks in your seat so that when you sit on them, the body responds by increasing your blood pressure and cardiac output. (disclaimer: do not do this. you will get tetanus and be a very unhappy camper.) there may not be nerve conduction through your damaged spine, but there is still a pain response. and i get odd stuff from my sinus pain, too. i can have quite a bit of inflammation, and not really feel it. yet, my heart rate is elevated, my mood is depressed, and thinking is sluggish. you can distract people all you want, but that doesn't mean their bodies aren't responding to what's being done to them.

[somasimple]

there may not be nerve conduction through your damaged spine, but there is still a pain response.

No message in nerves and still in pain? Where could it be produced? :confused:
You do not understand that pain is a reponse... not an incoming stimulus and there is no pain receptors: Nociception is not pain.
Cramps come spaticity and a spastic muscle creates chemical products. Pain is a complex response that may content endocrines.

A pain experience may involve a composite of sensory, motor, autonomic, endocrine, immune, cognitive, affective and behavioural components. Context and meaning are paramount in determining the eventual output response.

[somasimple]

let's say you're a paraplegic, and you want to cheat at wheelchair racing. one thing that might be done is to put tacks in your seat so that when you sit on them, the body responds by increasing your blood pressure and cardiac output.

And your example is rather silly and far from reality.
Many paraplegics have skin problems (http://en.wikipedia.org/wiki/Bedsore) and they do not feel any pain.

[Monique]

You do not understand that pain is a reponse... not an incoming stimulus and there is no pain receptors: Nociception is not pain. Would you disagree that there is a highly specialized neuron that only responds to noxious stimuli, who communicates this information accurately to the CNS? And that this stimulus would result in a variety of autonomic responses and may result in the experience of pain?

[somasimple]

Would you disagree that there is a highly specialized neuron that only responds to noxious stimuli, who communicates this information accurately to the CNS? And that this stimulus would result in a variety of autonomic responses and may result in the experience of pain?


You do not understand that pain is a reponse... not an incoming stimulus and there is no pain receptors: Nociception is not pain.

And that this stimulus would result in a variety of autonomic responses and may result in the experience of pain?

Did you said "may"? That is not mandatory in that case. o:)

[Proton Soup]

No message in nerves and still in pain? Where could it be produced? :confused:
You do not understand that pain is a reponse... not an incoming stimulus and there is no pain receptors: Nociception is not pain.
Cramps come spaticity and a spastic muscle creates chemical products. Pain is a complex response that may content endocrines.

well, yes, not an actual pain receptor but, say, a pressure or temperature sensor. and when noxious stimuli send them over some threshold, there are physiological responses beyond the simple perception of "pain" in the brain.

in any case, the effects of stimuli that cause pain go beyond the perception in the brain, and do not require metabolic byproducts of muscle stimulation.

[Monique]

And that this stimulus would result in a variety of autonomic responses and may result in the experience of pain?

Did you said "may"? That is not mandatory in that case. o:) I think it should be very clear that nociceptors send a signal and that the brain respond to that.

[zoobyshoe]

A favorite of mine from this book:
ALL PAIN IS REAL!
No one has disputed this.

It seems that I didn't say something like that.
And you may search something about pain distraction (http://www.ampainsoc.org/pub/bulletin/spr05/inno1.htm).
Psychological treatment of physiological pain has been explored for years, particularly pain control by hypnosis. The results have always been mixed: different patients exhibit differing levels of responsiveness. The fact it can work to some extent does not mean the original physiological pain was psychological!

As far as I can tell we are in complete agreement about everything except the meaning of the word psychological. You seem to be asserting that everything that happens in the brain is psychological.

All psychological experiences arise from physiological processes but no physiological processes are psychological. This is true because of the meaning of the words. I posted the meaning of the word psychological quoting directly from the dictionary, and you rejected that meaning. That's idiosyncratic, to say the least.

[somasimple]

well, yes, not an actual pain receptor but, say, a pressure or temperature sensor. and when noxious stimuli send them over some threshold, there are physiological responses beyond the simple perception of "pain" in the brain.

in any case, the effects of stimuli that cause pain go beyond the perception in the brain, and do not require metabolic byproducts of muscle stimulation.
No. Pressure or heat is transmited by nerves => No message => No pressure or heat.

I think it should be very clear that nociceptors send a signal and that the brain respond to that.
No. It will respond if necessary.

The fact it can work to some extent does not mean the original physiological pain was psychological!

I just said the contrary. I said (one more time) that all pain is real and I added that all psychological events are real too (are physical).

[somasimple]

I posted the meaning of the word psychological quoting directly from the dictionary, and you rejected that meaning.
I reject its meaning because it is outdated.

[Monique]

I don't think there is any reason to continue this discussion, as it is going nowhere.

[somasimple]

I don't think there is any reason to continue this discussion, as it is going nowhere.

Really? It is going to the actual knowledge about brain and pain but you may follow your own way if you want. That is tolerance.
I prefer to believe in knowledge taught by the IASP (International Association for the Study of Pain) than an obsolete definition that needs a serious refinement.
Science evolves. It is an unpleasant thing for many...

[Proton Soup]

i don't think anyone sees what your point is. it's somewhat interesting that you can use a psychological means to cope with pain. but it doesn't actually fix anything, it's just a coping mechanism.

[somasimple]

i don't think anyone sees what your point is.
I'm in the same condition. :redface:

[turbo]

Really? It is going to the actual knowledge about brain and pain but you may follow your own way if you want. That is tolerance.
I prefer to believe in knowledge taught by the IASP (International Association for the Study of Pain) than an obsolete definition that needs a serious refinement.
Science evolves. It is an unpleasant thing for many...You seem to be remarkably able to ignore some medical facts and re-interpret them as wanted. It is possible (as I can well-attest, since I live with it) to have real localized brain injuries that result in the perception of pain when no tissue damage is being experienced. In my case, my right foot feels like it is being roasted 24/7 because of a stoke that damaged a small part of my brain-stem.

The pain is a result of physiological damage, and it won't go away, nor can it be lessened by any drugs that my doctors tried. There is no psychological component to the damage (which was very evident in the MRIs) nor is there a psychological component regarding treatment options unless my doctors have been in a coma for the last 15 years or so. Our perception of pain arises not in peripheral tissues, but in the brain, and if the brain is injured, we can be forced to experienced pain, no pain, discomfort, etc, in parts of our bodies that are far removed from that injury.

[somasimple]

You seem to be remarkably able to ignore some medical facts and re-interpret them as wanted. It is possible (as I can well-attest, since I live with it) to have real localized brain injuries that result in the perception of pain when no tissue damage is being experienced. In my case, my right foot feels like it is being roasted 24/7 because of a stoke that damaged a small part of my brain-stem.

You seem to be remarkably able to ignore all my posts. I'm just saying the things you're telling us.

http://www.physicsforums.com/showpost.php?p=2044691&postcount=6
Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons. There is usually no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain. This definition avoids tying pain to the stimulus. Activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state, even though we may well appreciate that pain most often has a proximate physical cause.
Did I said either that Medicine is a miracle provider? No. Unfortunately there are many cases where we have no solution, actually.

[Monique]

I think what turbo-1 is describing is neuropathic pain (a chronic pain as a result from an injury to the nervous system), which is different from nociceptive pain.

[somasimple]

Perhaps: Neuropathic pain is a dysfunction of the nerve (or of another neural component) itself. Neuropathic pain have also many components; peripheral (local) and central.

In my case, my right foot feels like it is being roasted 24/7 because of a stroke that damaged a small part of my brain-stem.
In the described case, it seems a central pain. It is a complex pain and it is very difficult to find a solution. The mirror box may help to normalize the two sides.
A central problem may also creates peripheral problems...