The Impact of Movement on Nerve Signaling and Cellular Function

The Science Behind How Movement Changes Nerve Signaling to Every Tissue, Cell and Organ; Even your DNA!

You see how much we move, the variation between how intense we move to the varying terrains in our environment have adaptive epigenetic controls to our health and well-being. 

According to a study in Canada, teens between the ages of fifteen and seventeen walk an average of eleven minutes a day; when they need closer to 8-10 miles a day.

MOVE YOUR DNA

Biomechanist Katy Bowman in her book Move Your DNA, would tell you that if you were part of an ancient hunter-gatherer tribe, your development would have resembled this scenario:

"Following an entirely unmedicated birth, you, a hunter-gatherer baby, were breastfed, slept with your parents, and exercised multiple times daily. You reached standing and walking milestones at the time many modern kids begin crawling. Exclusively held, you began “core exercising” with every step your parents took (all outside), your body position shifting minute to minute as you or your holder required, allowing you to explore both the world and an infinite number of body loads via varying positions.”

Infancy years

“Just before age two, you were play-gathering, with repeated squatting and standing, digging and clambering, for hours a day. When not play-gathering, you played in constantly varying terrain. This all-day movement (and variability to movement) developed the skills, strength, and shape you would eventually need in order to function as an adult, and your gait and walking patterns were much less toddler-like and wobbly because you didn’t wear diapers. 

Your pelvis and hips took the shape necessary to continue squatting, sitting on the floor, and walking a ton, and were not influenced by kid carriers, car seats, or continuous time in a single position.”

Puberty

“Shortly after puberty, probably age fourteen, you were a fully functioning member of a tribe, participating in the same all-day movement patterns as your parents and walking medium (three-mile) to long (ten-mile) distances most days of your life. You walked every day and worked hard harvesting and carrying enough bounty to ensure survival. The frequent, weight-bearing loads of walking maximized your peak bone mass during the most crucial period of young adulthood."

Let’s contrast our ancestors’ lifeways, which is supposed to be the same today as how most of us live today.

"As an adult, you don’t exercise regularly, or ever, really. Instead, you use your body to get life done. Your total movements, varying joint positions, and rate of energy expenditure for a day’s survival work easily exceed those found in a standard athletic workout. And in addition to moving more, you also relax frequently. You don’t have the stress of driving, constant noise, constant information, and excessive light.”

Imagine your body is made out of clay and you reconfigure the shape and function of your clay body into this shape. A shape brought about by nature.

What Does Your Body Shape Say About You?

“Anthropologists and medical researchers alike have concluded that the way humans move now is drastically different from how humans have moved over the bulk of the human timeline, which is easy to see once you compare your own physical timeline with that of someone in a traditional hunter-gatherer society.”

Science is very clear.

“The physical requirements of the human body—the body loads that drive many of the functions we depend on for living—are not well met by the quantity and types of loads created in modern society.”

Most cells depend heavily on mechanical stimulation.

“The loads placed on the body via movement translate into loads on the cells themselves, which creates cellular data, and it is at this level that change—in the form of strengths, densities, and shape—occurs.”

Movement provides information for the body.

“We use the word disease to imply that something has gone awry in our bodies; but as I said before, more often than not, our bodies are simply responding normally to the input they’re given. Movement provides information for the body. Movement is an environmental or epigenetic factor. Our movement environment has been polluted, so to speak, and we’ve got the bodies to match."

 

CHIROPRACTIC CARE

Once again, this is why the frequency of visits to a chiropractor is important. Again, healthy movement in the joints is going to decrease matrix catabolism and stimulate regenerative capabilities.  Less motion in the joints is going to increase matrix catabolism.  

Mayo Clinic and NASA research on immobility and sitting disease suggest moving for three minutes every 30 minutes in order to mimic the lifeways of our ancestors who moved 8-10 miles every day and by doing so you are ensuring healing and regeneration; not moving that much you are ensuring degeneration and decay; that is the take away point here.

THE SCIENCE

As for compression, like squatting, kneeling, or sitting on the floor like how our ancestors were who didn’t lay on beds, they laid on the floor, or sit on chairs, they squat or kneeled on the floor, they even ate on the floors. Well, recent advances in mechanobiology found a way to study compression‐induced mechanotransduction that is involved in these daily movements it included the use of some of the elastomeric substrate techniques I noted earlier.

For example, one study found that applied compression to cells on various PDMS substrates to determine its effects on cell-substrate interactions and morphological changes and found that compression caused the overall cell structure, including the actin cytoskeleton, to reorient in the direction of the compression applied.

DEGENERATIVE JOINT DISEASE IS DEFICIENT MOVEMENT DISORDER

This means it’s demonstrating the complexity and sensitivity of IVD cell responses to varying conditions like immobile spinal joints, DDD, squatting, laying down, sitting, and the impact those forces have not only on our spinal health but our biological health.

As another example, the effects of two factors alone, that is the age of the intervertebral cells and the frequency of the dynamic compression applied, have demonstrated dependence on variations in one another, with more mature cells responding quite differently (in terms of cellular phenotypes, rates of biosynthesis, and the production and maintenance of ECM components) to different compression frequencies than less mature cells.

Research suggests

At the same time, these findings and those of related studies suggest that mechanotransduction itself especially from normal spinal motion, may have different pathways of activation depending on conditions as discrete as, say, the specific frequency of the applied tensile or compressive strain, how well, and often you move, how well maintained your spinal health is, and on and on.

In any case, as complex as these interactions are, further studies will continue to illuminate their characteristics, providing important insights to improve our understanding of mechanotransduction, disc degeneration, and potential therapies to repair or prevent such degeneration.

Mehanical Forces

The means by which the above mechanical forces cause their most important effects on various cells is mechanotransduction propagated through nerve signaling picked up like a motion detector system loaded in spinal joints through mechanoreceptors and joint proprioceptors loaded in the disc.

CHIROPRACTIC TAKE AWAY POINT

Without spine-induced mechanotransduction, a compressive force would, for example, cause the nucleus pulposus of a disc to be physically deformed by a decrease in its height, but a whole host of critical intracellular changes in terms of gene expression, protein synthesis, and even proliferation would not occur. In a sense, the capacity for mechanotransduction is one of the qualities that distinguish living tissues from most inanimate substances.

– DR. MATT HAMMETT

Mechanoreceptors 

These mechanoreceptors facilitate the transmission of mechanotransductive forces to cellular biochemical actions. Localized in nerve terminals, they allow tissues to respond directly to touch, vibration and pressure, among other physical stimuli.

Mechanoreceptors begin the biological response to mechanical stress through the firing of action potentials or nerve signaling.

TYPES OF MECHANORECEPTORS

Various types and concentrations of mechanoreceptors are found in different parts of the body. But they are most populated in the spine, especially the upper cervical spine.

A study of sequential sections of human and bovine spines found that the mechanoreceptors in the annulus fibrosus and longitudinal ligaments consisted primarily of Pacinian corpuscles, Ruffini endings, and, most frequently, Golgi tendon organs.

Types

It is suggested that the Pacini and Ruffini endings are primarily related to posture, while the Golgi tendon organs are related to pain. These are also proprioceptors.  

In this connection, they noted that Golgi tendon organs were found in differing percentages of discs from patients with scoliosis about 15% and lower back pain about 50%.

MRI STUDIES

In a later study using magnetic resonance imaging to conduct a more direct comparison of mechanoreceptors in healthy and degenerated discs, one study found that mechanoreceptors play critical roles in different phases of disc degeneration, with a greater number of mechanoreceptors being found in degenerated discs than in normal discs.  

Often when I perform a chiropractic exam of the spine using motion palpation I can feel the level of stiffness, and usually the greater the stiffness in a joint I usually find greater signs of DDD at that level on X-ray and pain only sometimes show up there. So pain is not the indicator, it’s the stiffness of the spine.

With this in mind, the authors suggest that magnetic resonance provides a highly efficient means of detecting even the early phases of disc degeneration, even as other authors have pointed out that the precise implications of these initial changes remain obscure.

One of the primary means by which mechanoreceptors propagate the chain of mechanotransductive effects in cells is by altering intracellular levels of gene expression. The normal segmental motion of your spine is the main mechanism most experts have dropped the ball on. This has direct effects on all the fundamental activities within and between cells, including proliferation, apoptosis, and protein and enzyme synthesis, among others.

MECHANOTRANSDUCTION

Mechanotransduction, as you know by now, is the process by which cells sense and respond to mechanical signals. You also know that, through body loads, mechanical signals are being created 100 percent of the time, both by our movements and by how we are positioned when we’re not moving. Movement (not only exercise, but every gesture, big or small, made by the human body) loads the body’s tissues and the body’s cells.

Every cell contains a rigid network called a cytoskeleton, similar in function to our bones. Most recent findings in cellular biomechanics show that the deformation of the cell itself, and the load placed on the cytoskeleton, affect each cell’s behavior, including how the cell regenerates.

Today, there is a large volume of scientific research regarding the effects physical loads have on the ailments and injuries we develop. Still, the greatest allocation of resources (and magazine headlines) focuses on genetic pre-determinism and biochemical markers (like high cholesterol in the case of heart disease).

Despite scientific understanding that virtually all cells adapt to accommodate their mechanical environment and that biochemical signals for genetic expression might not even be necessary (it appears the cytoskeleton can directly transmit mechanical signals to the DNA via recently identified “cytofiliments”; our physical experience is repeatedly presented as an event—such as how we have used our bodies since birth.

WHAT GENES TELL OUR BODIES

For example, your genes contain information about the ratio of muscle fiber types you have, which affects the potential for your muscles to develop in response to exercise—for instance, whether you’ll ever be able to be a world-class sprinter—but genes do not run the programs for developing your body into an athlete’s. Rather, this development occurs when you create stimulation through your actions.

If you (and your genes) lay in bed for fifteen years beginning the day you were born, you would not end up looking the same (in person or on paper) as you would have had you (and your genes) been upright and moving around for fifteen years. This is an extreme example, but all movement and lack of movement create subtle differences in outcome in individuals and their genes.

Accordingly, close examination of gene expressions under varying circumstances can elucidate the means by which mechanotransduction occurs under different circumstances. 

MOVEMENT CHANGES GENE EXPRESSION IN DNA

For example, another study used dynamic compression combined with an RGD inhibitory peptide to demonstrate that nucleus pulposus cells from degenerated discs have a different mechanotransduction pathway than cells from healthy discs.

More specifically, they showed that this peptide called RGD integrins, was responsible for mechanosensing in the non‐degenerated disc cells, while cells from degenerated discs exhibited a different signaling pathway that excluded them.

For example, a finding regarding the role of integrins in annulus fibrosus cells similar to that which one study reported in nucleus pulposus cells was recently detailed by a different scientist who specifically found that, while RGD integrins do mediate the mechano‐response of non‐degenerated annulus fibrosus cells to cyclic tensile strain, these integrins are excluded from the same mechanotransduction pathway in annulus fibrosus cells from degenerated discs.

DEGENERATIVE DISC DISEASE

To sum the two studies up, RGD integrins mediate signaling pathways in both nucleus pulposus and annulus fibrosus cells from healthy discs, but they somehow become excluded from the mechanotransduction pathways in the same types of cells derived from unhealthy discs.

INTEGRINS

One of the key means by which integrins transmit their effects on transduction is via their connections to the cytoskeleton. One study used magnetic twisting to demonstrate the close continuity between cytoskeleton and integrins, showing that they are firmly attached to eachother.

Another study showed how the application of such twisting to integrin receptors results in increased gene expression.

In fact, a variety of proteins, including tensin, talin and filamin, among others, have been shown to include binding domains for both cytoskeleton and integrins, providing various means for their direct physical linking.

Cytoskeletal elements themselves (e.g. microtubules and the Golgi apparatus) are directly affected by mechanical forces. For example, a different study demonstrated that when hydrostatic pressure on cells becomes too high, these elements can become disorganized, hindering both protein synthesis and transport across the cell membranes.

SQUATS AND DEAD LIFTS: BE CAREFUL

So, you want to be careful of too heavy of squats and deadlifts.

At the same time, the cytoskeleton can undergo reorganization in response to hypo‐osmotic conditions, a finding that is directly relevant to degeneration in IVDs, precisely because osmotic pressure changes as a result of decreased water content are known to be among the most profound changes that occur in IVDs as individuals go through the process of immobility induced aging like I said, stuck, stiff joints not moving efficiently.

LATEST RESEARCH IN DISCS

New cutting‐edge research offers additional possibilities for exploring the effects of osmotic pressure on mechanotransduction involving various cell structures, including cytoskeletal elements in IVDs.

This is basically saying that the normal joint movement between segmental vertebrae in the 25 moveable vertebrae in the spine improves the health of the cytoskeleton inside the IVD, strengthening it, causing stronger Protein Anchorage for regeneration and healing, and it increases the mechano transductive nerve signaling pathways to further stimulate disc regeneration.

In fact, the complexity of a mechanotransduction pathway shows a model of how this signaling pathway regulates gene expressions in the nucleus pulposus cells in the context of both disc degeneration and regeneration.

TODAY’S CHIROPRACTIC RESEARCH

In short, restoring the normal movement of your spine by a trained chiropractor who assesses both the movement, posture, alignment, duration, and frequency of both your tiny all-day movement as well as the frequency of your chiropractic care have huge biological factors including improving cellular function, gene expression and improving your DNA function, more so than simply getting out of pain.  

I talked briefly about a proprioceptive organ called Golgi tendon organs and how they loaded within the IVD.

MAJOR THEORY

One of the major theories in chiropractic today concerns another proprioceptive organ called muscle spindles, which are loaded in muscle. One such sensor exists within the deeper layer of muscles called paraspinal muscles which contract and relax during the normal segmental motion of all 25 moveable bones in our spine. These sensors relay a circuit to the brain and have huge benefits to our brain health. The leading researcher in chiropractic is Dr. Heidi Haavik. I had the chance to sit down and talk with her after a seminar in Chicago.

 

Heidi told me that:

muscle spindles are tiny little stretch sensors found inside the muscles. They play a very important role in sensorimotor integration (our brain’s ability to sense movement and tell muscle what to do) and most likely also play a very important role in the mechanisms of spinal adjustments.” – Dr. Heidi Havvik Ph.D.

 

STRETCHING

Every time your muscle is used or is “stretched” in any way, the muscle spindles tell your brain about it immediately. Basically, the muscle spindles are your brain’s “eyes” within your muscles,” she said. It’s the tiny deeper layer of muscles called the parspinal muscles that only a specific chiropractic adjustment is able to stretch and target the brain’s sensory system especially the prefrontal cortex.

Heidi, along with her cutting-edge brain mapping technologies, spends most of her days studying the effects of chiropractic adjustments on muscle spindle activity.

WHAT HAPPENS DURING A CHIROPRACTIC ADJUSTMENT

When chiropractors adjust the spine, by giving a small thrust into stiff areas of the spine, it stretches the paraspinal muscles. One group of scientists found that muscle spindles in the paraspinal muscles in cats responded to forces applied to the vertebrae that are similar to the forces delivered during spinal adjustments. Another group of scientists has shown that spinal adjustive thrusts can evoke short-lasting electromyographic (EMG) responses in paraspinal muscles. Electromyography (EMG) measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle. These studies demonstrate that chiropractic adjustments are sensed by the muscle spindles inside the paraspinal muscles, which will then feed this information up to the brain.

SUBLUXATION

An animal model was developed for studying what the different parts of the nervous system would do when you immobilize vertebrae out of their natural alignment and function. They found that this small displacement is signaled to the brain and central nervous system from nerves arising from a different deep muscle that runs between adjacent vertebrae called intervertebral muscles. In particular, both the speed of vertebral movement and the relative position of the vertebral displacement appeared to be encoded by nerve activity from intervertebral muscles.

So, now we know at least two groups of deep layers of muscle between adjacent spinal segments carry proprioceptive input into the brain and switch on the 6th sense. Heidi says “this supports the idea that the deep muscles close to the spine are sensors for the brain that tell the brain what is happening in the spine”. Heidi believes that vertebral subluxation is likely to alter the input to the brain from the lack of normal spinal motion between adjacent joints in the deep paraspinal muscles. “This may lead to ongoing maladaptive plastic changes in the brain”, she says. 

HOW CHIROPRACTIC WORKS

How exactly?

What goes on in the microscopic spaces between our specialized cells called neurons that transmit nerve impulses is exceedingly complicated. In biochemical terms, it involves various chemical reactions that register and record experiences in neural pathways. In biomechanical terms, every time we perform a movement task, especially movement of the spine, a set of neurons in our brains is activated.

BRAIN HEALTH

The brain receives that first spark from the movement of our body especially the movement of the spine via the activation of two sensors (proprioceptors) body position sensors and (mechanoreceptors) body load sensors that charge these neurons to join through the exchange of synaptic neurotransmitters. This joining permits a nerve cell to pass an electrical or chemical signal to another neuron and turn on many types of neurotransmitters which release chemicals that nerve cells use to send signals to other cells.

REPEATED ADJUSTMENTS

As the experience (especially the chiropractic adjustments) is repeated, the synaptic links between the neurons grow stronger and more plentiful. The strength of these links is achieved through both physiological adaptations, such as the release of higher concentrations of neurotransmitters, and anatomical ones, such as the generation of new neurons or the growth of new synaptic terminals on existing axons and dendrites.

CELL PHYSIOLOGY VIA MOVEMENT

These are the long and short threadlike parts of a nerve cell along which impulses conduct from the cell body to other cells. Synaptic links can also weaken in response to experiences, again as a result of physiological and anatomical alterations such as poor posture, alignment, and immobility caused by a sedentary lifestyle. 

What we learn as we live is embedded and recorded in ever-changing cellular connections inside our brains. The chains of linked neurons form from these physical inputs and mental experiences our minds’ true vital paths actually grow and adapt. 

HEBB’S RULE

Today, scientists sum up the essential dynamic of neuroplasticity with a saying is known as Hebb’s rule: ‘neurons that fire together wire together.’” A sedentary lifestyle alters this response in reverse, the brain actually shrinks. For the first time in our history as a species, the brain is actually shrinking. None of this is a theoretical construct or a philosophical ideology. All of this is worked out in science! Please understand something in science with what we consider evidence. The human anatomy and physiological textbooks in America are from northern American people (only 4 -6 % of people on the globe). 

WESTERN SCIENCE STUCK IN 17TH CENTURY

The textbooks used in science like Guyton’s textbook on medical physiology or the biochemistry books are very misleading regarding actual evidence. They should be corrected to read rat medical physiology and rat biochemistry; most of what we think we know about humanity that we call evidence-based does not come from humanity! It is an anamorphic lens that bends reality!

Not to mention we simply don’t live in a vacuum. The rats they use are not even found in nature that way; they are lab bread for specific experiments. This is 17th-century rat science and still very much the predominant system in science today!

Chiropractic care is superb and science is finally learning how by restoring joint function like a motion system stimulate mechanotransductive pathways that help regulate your brain function, to proper cellular, tissue, and organ function; right down to the nano scaling of your genetic expression in your DNA. 

Get to a chiropractor who understands how to implement the new biology, and you will never be the same again!

 

References:

1. Sowa G, Agarwal S. Cyclic tensile stress exerts a protective effect on intervertebral disc cells. Am J Phys Med Rehabil. 2008; 87: 537–44.
2. Gilbert HTJ, Hoyland JA, Millward-Sadler SJ. The response of human anulus fibrosus cells to cyclic tensile strain is frequency-dependent and altered with disc degeneration. Arthritis Rheum. 2010; 62: 3385–94.
3. Cheng CM, Steward RL, LeDuc PR. Probing cell structure by controlling the mechanical environment with cell–substrate interactions. J Biomech. 2009; 42: 187–92.
4. Korecki CL, Kuo CK, Tuan RS, et al. Intervertebral disc cell response to dynamic compression is age and frequency dependent. J Orthp Res. 2009; 27: 800–6.
5. Salter DM, Robb JE, Wright MO. Electrophysiological responses of human bone cells to mechanical stimulation: evidence for specific integrin function in mechanotransduction. J Bone Miner Res. 1997; 12: 1133–41.
6. Gillespie PG, Walker RG. Molecular basis of mechanosensory transduction. Nature. 2001; 413: 194–202.
7. Roberts S, Eisenstein SM, Menage J, et al. Mechanoreceptors in intervertebral discs: morphology, distribution, and neuropeptides. Spine. 1995; 20: 2645–51.
8. Oliveira VM, Puertas EB, Alves MTS, et al. Comparative study of normal and degenerated intervertebral discs’ mechanoreceptors of human lumbar spine by x-ray, magnetic resonance and anatomopathologic study. Acta Ortop Bras. 2007; 15: 35–9.
9. Palmgren T, Grönblad M, Virri J, et al. An immunohistochemical study of nerve structures in the anulus fibrosus of human normal lumbar intervertebral discs. Spine. 1999; 24: 2075–9.
10. Christian W. A. Pfirrmann, Alexander Metzdorf, Marco Zanetti, et al. Magnetic Resonance Classification of Lumbar Intervertebral Disc Degeneration. Spine. 2001; 26: 1873–1878.
11. Le Maitre CL, Frain J, Millward-Sadler J, et al. Altered integrin mechanotransduction in human nucleus pulposus cells derived from degenerated discs. Arthritis Rheum. 2009; 60: 460–9.
12. Gilbert HT, Nagra NS, Freemont AJ, et al. Integrin-dependent mechanotransduction in mechanically stimulated human annulus fibrosus cells: evidence for an alternative mechanotransduction pathway operating with degeneration. PLoS ONE. 2013; 8: e72994.
13. Wang N, Ingber DE. Probing transmembrane mechanical coupling and cytomechanics using magnetic twisting cytometry. Biochem Cell Biol. 1995; 73: 327–35.
14. Chen J, Fabry B, Schiffrin EL, et al. Twisting integrin receptors increases endothelin-1 gene expression in endothelial cells. Am J Physiol Cell Physiol. 2001; 280: C1475–84.
15. Liu S, Calderwood DA, Ginsberg MH. Integrin cytoplasmic domain-binding proteins. J Cell Sci. 2000; 113: 3563–71.
16. Hall AC, Urban JP, Gehl KA. The effects of hydrostatic pressure on matrix synthesis in articular cartilage. J Orthop Res. 1991; 9: 1–10.
17. Ishihara H, Warensjo K, Roberts S, et al. Proteoglycan synthesis in the intervertebral disk nucleus: the role of extracellular osmolality. Am J Physiol. 1997; 272: C1499–506.
18. Tan C, Saurabh S, Bruchez M, et al. Molecular crowding shapes gene expression in synthetic cellular nanosystems. Nat Nanotechnol. 2013; 8: 602–8.
19. Pavalko FM, Norvell SM, Burr DB, et al. A model for mechanotransduction in bone cells: the load-bearing mechanosomes. J Cell Biochem. 2003; 88: 104–12.
20. Whitmarsh AJ, Davis RJ. Transcription factor AP-1 regulation by mitogen-activated protein kinase signal transduction pathways. J Mol Med. 1996; 74: 589–607.
21. Zhao CG, Wang LM, Jiang LS, Dai LY. The cell biology of intervertebral disc aging and degeneration. Aging Res Rev. 2007; 6: 247–261.