self organization of muscle reflexes

[scruffy]

Up till now, most people thought spinal reflexes were organized by genetic markers.

But that's impossible, because the number of markers required would be astronomical.

Here's how it really happens. Demonstrated by a very simple model.

A model for self-organization of sensorimotor function: the spinal monosynaptic loop - PMC

Keywords: extrafusal muscle, intrafusal muscle, muscle spindle, neuron model, spinal development

pmc.ncbi.nlm.nih.gov

Human beings (and spines) have "segments", just like worms have segments. Humans only have about 20 of them, a lot less than most worms. You probably already know about the spinal segments: cervical, thoracic, lumbar, and sacral.

In the spinal cord and brainstem, the segments are organized into three major parts: gracile, cuneate, and trigeminal - for the lower and upper extremities and face, respectively.

So how does a sensory nerve in the toe, find its corresponding muscle? The sensory nerve lives near the spinal cord in an area called the "dorsal root ganglion". Whereas the motor neuron that drives the muscle, lives in the ventral horn of the spinal cord itself. How does the toe nerve know to connect to "its" muscle and ignore all the others?

The answer is, it self-organizes exactly the same way speech does. In the womb the fetus "babbles", the muscles twitch, which results in sensory signals from the muscle spindles. The spindles that activate at the same time as the muscle twitches, end up connecting to the muscle.

In the fetus, sensory axons sprout across entire segments, and then they are "pruned" by correlated neural activity. The sprouts that don't correlate, die off. Leaving the classic "monosynaptic reflex".

No genetic markers are needed. Only correlated neural activity based on random muscle twitching.

 

[shockedcanadian]

Up till now, most people thought spinal reflexes were organized by genetic markers.

But that's impossible, because the number of markers required would be astronomical.

Here's how it really happens. Demonstrated by a very simple model.

A model for self-organization of sensorimotor function: the spinal monosynaptic loop - PMC

Keywords: extrafusal muscle, intrafusal muscle, muscle spindle, neuron model, spinal development

pmc.ncbi.nlm.nih.gov

Human beings (and spines) have "segments", just like worms have segments. Humans only have about 20 of them, a lot less than most worms. You probably already know about the spinal segments: cervical, thoracic, lumbar, and sacral.

In the spinal cord and brainstem, the segments are organized into three major parts: gracile, cuneate, and trigeminal - for the lower and upper extremities and face, respectively.

So how does a sensory nerve in the toe, find its corresponding muscle? The sensory nerve lives near the spinal cord in an area called the "dorsal root ganglion". Whereas the motor neuron that drives the muscle, lives in the ventral horn of the spinal cord itself. How does the toe nerve know to connect to "its" muscle and ignore all the others?

The answer is, it self-organizes exactly the same way speech does. In the womb the fetus "babbles", the muscles twitch, which results in sensory signals from the muscle spindles. The spindles that activate at the same time as the muscle twitches, end up connecting to the muscle.

In the fetus, sensory axons sprout across entire segments, and then they are "pruned" by correlated neural activity. The sprouts that don't correlate, die off. Leaving the classic "monosynaptic reflex".

No genetic markers are needed. Only correlated neural activity based on random muscle twitching.

Does the "self-organization" occur in a fully developed, mature human? Can one improve this through some deep massage and/or stimuli of some kind? I have potential issues that might be neuopathic in nature and I've tried to assess all potential causes, from my former time.as a.very active.athlete to other potential.contributors. I am a firm believer in the magic of the body, G-ds most perfect creation. It is the what and how that I need to find answers to. This does include random muscle twitching

 

[scruffy]

Does the "self-organization" occur in a fully developed, mature human?

Yes. After injury, the axons sprout again. Also, stem cells can be implanted resulting in fresh sprouts.

If there is actual damage to the muscle spindles, the cerebral cortex can also take over some of the muscular control.

Can one improve this through some deep massage and/or stimuli of some kind?

Yes. 100 Hz electrical stimulation is often effective.

I have potential issues that might be neuopathic in nature and I've tried to assess all potential causes, from my former time.as a.very active.athlete to other potential.contributors.

Have you had an EMG? They can be done noninvasively now, as "surface EMG".

I am a firm believer in the magic of the body, G-ds most perfect creation. It is the what and how that I need to find answers to. This does include random muscle twitching

Neuropathy has many forms. "Random muscle twitching" could be a lot of things. Better than a standard neurologic exam, would be a correlation of EEG and EMG. That can distinguish for example, between peripheral neuropathy and cerebellar involvement. Are there other peripheral symptoms like tingling and numbness?

 

[shockedcanadian]

Yes. After injury, the axons sprout again. Also, stem cells can be implanted resulting in fresh sprouts.

If there is actual damage to the muscle spindles, the cerebral cortex can also take over some of the muscular control.



Yes. 100 Hz electrical stimulation is often effective.



Have you had an EMG? They can be done noninvasively now, as "surface EMG".



Neuropathy has many forms. "Random muscle twitching" could be a lot of things. Better than a standard neurologic exam, would be a correlation of EEG and EMG. That can distinguish for example, between peripheral neuropathy and cerebellar involvement. Are there other peripheral symptoms like tingling and numbness?

Yes. Prickly feelings all over, as if spiders are on my skin. It happens in unison fkr.aboit 20-30 seconds,.dosn eachnleg,.arms, neck,.fsce.then just as fast as it started it stops. Numbness and even weakness.sometimss. All random. This also corresponds wi pain behind one eye

 

[scruffy]

Yes. Prickly feelings all over, as if spiders are on my skin. It happens in unison fkr.aboit 20-30 seconds,.dosn eachnleg,.arms, neck,.fsce.then just as fast as it started it stops. Numbness and even weakness.sometimss. All random. This also corresponds wi pain behind one eye

I'd recommend an immediate medical evaluation including MRI. Pain behind the eye could be something as simple as optic neuritis (inflammation of the optic tract), but when coupled with the somatic symptoms you describe suggests a broader inflammation, including things as serious as MS or other auto-immune type conditions. The pain behind one eye (but not both? Is it always the same eye?) is called "hemiplegic" - migraines sometimes cause the collection of symptoms you're describing. Hemiplegic migraines are usually treatable with pharmaceuticals. The more dangerous condition would be an infection at the brainstem level (top of the spinal cord), which is serious and should be looked at right away. A brain scan can eliminate the more dangerous possibilities, things like MS lesions and internal infections would show up. Beyond that I have to state I'm not an MD and can't give medical advice and am not licensed to diagnose. I strongly suggest you visit a qualified specialist as soon as possible. May I ask, how frequent are the 20-30 second episodes? Once a day, or several per day? Are they correlated with any activity? (Eating, exercising, watching TV?)

 

[shockedcanadian]

I'd recommend an immediate medical evaluation including MRI. Pain behind the eye could be something as simple as optic neuritis (inflammation of the optic tract), but when coupled with the somatic symptoms you describe suggests a broader inflammation, including things as serious as MS or other auto-immune type conditions. The pain behind one eye (but not both? Is it always the same eye?) is called "hemiplegic" - migraines sometimes cause the collection of symptoms you're describing. Hemiplegic migraines are usually treatable with pharmaceuticals. The more dangerous condition would be an infection at the brainstem level (top of the spinal cord), which is serious and should be looked at right away. A brain scan can eliminate the more dangerous possibilities, things like MS lesions and internal infections would show up. Beyond that I have to state I'm not an MD and can't give medical advice and am not licensed to diagnose. I strongly suggest you visit a qualified specialist as soon as possible. May I ask, how frequent are the 20-30 second episodes? Once a day, or several per day? Are they correlated with any activity? (Eating, exercising, watching TV?)

The episodes specific to the rapid tingling prickly feeling all around my.body have occured only maybe 15-20 times.over the last few.months. Unpredictable.and unexpected. I could be lying down or I could be walking. I do suffer from individual incidents of tingling, isolated to a foot or a even the side of my body or hip. I have some.numbness too that arrives and disappears. I am working with a neurologist for more.tests but the process is slow. When I talk alot it gets worse.at times to the point I feel a rush of shock or.fear (fight or.flight). If I exercise with push ups.etc the pain behind my eye becomes worse

 

[scruffy]

Hm. Well, the good news is it doesn't sound like a full fledged auto-immune condition. But it does sound biochemical, because it's generalized and gets worse with activity. Nerves are complicated, we don't understand them yet. Biochemically, they interact with other cells called "glia", for example astrocytes, which in turns interact with the immune system. Also there is immune linkage in the hypothalamus and in relation to the blood brain barrier.

In addition to an MRI which is mandatory in such situations, an immune screening sounds like a good idea. It's "blood work", they take a bunch of your blood and analyze it. I'll just cite a few names of tests, so you'll get the landscape. Anti-nuclear antibody test, auto-antibody test, complete blood count, C-reactive protein test, erythrocyte sedimentation rate, and of course urinalysis. It's not usual for a neurologist to recommend these types of tests, so a good idea might be to complement the neurologist with another specialist, like an immunologist.

The symptoms you're describing fall into the category of "generalized" neuropathy. The link with metabolism is things like diabetes, alcohol use, toxins (including heavy metals and even perhaps other pharmaceuticals), and vitamin deficiency. Do you take vitamins? Something you could try yourself without a doctor is loading up on B-12 and see if that helps. Or you could for example take two Centrums every day and see if you get any relief that way. Centrum is very good, it has almost everything your body needs. One-A-Day is not as good. Folic acid is also important, you can find the vitamins with more folate and less zinc.

Also consider a thyroid issue, sometimes that presents like neuropathy. Thyroid should be included in your immune screening. Neuropathy is not curable but it's usually treatable and manageable. Alternative treatments like acupuncture and massage with lotions can sometimes be very effective. If I were you I'd be proactive and not wait around for the neurologist. Alcohol and caffeine should be minimized if possible, along with anything that causes stress to the nervous system. Maybe you'll find a magic bullet, but more likely a combination of things will work, and you just have to find the best combination for you. The doctors can help with MRI and blood work, but they may end up telling you things you already knew. My friend in Philly has Sjogren's, she gets all the symptoms you're describing if she doesn't drink a Pediasure every day. Weird, none of her doctors can say why, but it works for her. It's mostly protein and electrolytes, who knows maybe one of the electrolytes is magic for her. She doesn't want to experiment further, it's sufficient that she's found a way to get relief. She's almost 70, she goes "the clerks at WalMart look at me funny when I buy a case of Pediasure but I don't care" lol