Neuroplasticity

Dr. Matthew McCoy - Editor editor@jvsr.com 
Journal of Vertebral Subluxation Research 
http://www.jvsr.com 

Continuing our discussion of neuroanatomy, I wanted to touch on the concept of neuroplasticity. This is not solely a chiropractic concept, although I think we know the most about it from a clinical perspective. If you pick up some major University catalogs and look through the course listings under the neuroscience programs you'll find semester long courses on this topic. For chiropractors, it's time our scientific understanding of this concept and its relationship to subluxation catches up with our clinical understanding of it.

The concept is also explained in an article that made its way through the chiropractic profession a short time back titled: Thalamic Neuron Theory: Theoretical Basis for the Role Played by the Central Nervous System (CNS) in the Causes and Cures of All Diseases (1). No D.D. or B.J. didn't write this one, but you'd swear the author has read their books! The gist of the article and the concept of neuroplasticity can be found in the abstract:

"Inherent in its capacity to learn and adapt (i.e. to habituate) is the CNS' ability to learn to be sick (pathological habituation) by looking in certain deranged central neural circuitries, leading to chronic disease states. These pathologically habituated states can be reversed by dehabituation through manipulation or modulation of the abnormal neural circuits by physical means (physical neuromodulation)"

Translation into chirospeak: A healthy nervous system, when confronted with the limitations of matter inherent in the introduction of a subluxation, sets up abnormal neurological reflex loops that can involve the entire neuroaxis and lead to disease. Furthermore, the patterns set up by the subluxation can be reversed by specific adjustment.

The article goes on further to explain that the "dehabituation" (correction) process can happen slowly in a "repetitious manner" over a long period of time and that it can also happen immediately, secondary to a significant one time event. Sounds like the old explanation of why some patients get better with one adjustment and others take months.

To begin an understanding of the intricacies of neuroplasticity and neurospinal learning we need to discuss Somatic Sensations and one of the classifications is Mechanoreceptive Somatic Senses.

There are 4 "types" of mechanoreptors. Type I receptors tell us where a joint is moving to, the strength and speed with which its moving, what the pressure is inside the joint and also tells us where the joint is, when it's not moving. Type II tell us when movement in the joint is speeding up or slowing down. Type III tell us when the joint is at the extremes of motion and Type IV are the pain receptors of the joints.

Its important to remember that mechanoreceptor activity makes up nearly 90 percent of all the information relayed to the Central Nervous System. A few points worth mentioning:

• These joint receptors are separate from the contributions made by the muscle receptors.
• The greatest concentration of mechanoreceptor populations are in the joints and connective tissue of the spinal column.
• The highest concentration is in the occipito-atlanto-axial region (3).

To make this even more exciting:

• The greatest load to the thalamus is from the cerebellum
• The greatest load to the cerebellum is unconscious mechanoreception
• Mechanoreceptors have the highest population of representation of thalamic projections in the entire nervous system (4).

So if you haven't had your atlas set by an upper cervical specialist, do so today!

This all means that the majority of sensory information that is transmitted to the cerebral cortex is a result of joint mechanoreceptor input (afferentation.) Increasing mechanoreceptor activity via a specific chiropractic adjustment has the potential to increase the ability of the nervous system to comprehend movements, joint position and posture. It may affect cognitive functions and the ability to perceive visual, auditory and olfactory phenomena as well as all aspects of human function.(3)

The adjustment does this by facilitating the effects of mechanoreceptor afferents on four aspects of function: Pain, sensation, motor system integrity and the autonomic nervous system. As always, I look forward to your feedback, comments and suggestions.

Regards, 
Dr. Matthew McCoy
Editor - Journal of Vertebral Subluxation Research.
http://www.jvsr.com 
editor@jvsr.com 

REFERENCES

1. Lee T.N.: Thalamic Neuron Theory: Theoretical Basis for the Role Played by the Central Nervous System (CNS) in the Causes and Cures of All Diseases. Medical Hypotheses: 1994: 43, 285-302.

2. McCoy M: Computerized Muscle Testing and the Neurology of the VSC: Part III. The Chiropractic Journal September 1996.

3. Adams R.W.: Primary Neurological Conditioning. June 1993. Unpublished Manuscript.