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AFFERENT FUNCTION IN THE GROUP OF NERVE FIBERS OF SLOWEST CONDUCTION VELOCITY

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DEAN CLARK, JOSEPH HUGHES, HERBERT N. GASSER · 1935

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This foundational 1935 study identified C fibers as crucial sensory pathways, the same vulnerable nerve types modern research links to EMF sensitivity.

Plain English Summary

Summary written for general audiences

This 1935 study by Clark investigated whether the slowest-conducting nerve fibers (called 'C fibers') could carry sensory information to the brain. Using cats, researchers found that these unmyelinated fibers do indeed transmit sensory signals and can trigger reflexes, establishing their role in the nervous system's communication network.

Why This Matters

While this 1935 neurophysiology study predates our EMF concerns by decades, it established fundamental knowledge about how our nervous system processes sensory information through different types of nerve fibers. The research demonstrated that C fibers, the slowest-conducting and most vulnerable nerve pathways, play crucial roles in sensory transmission. This matters enormously for EMF health because these same delicate, unmyelinated fibers are precisely what modern research suggests may be most susceptible to electromagnetic interference. When we consider that wireless radiation can disrupt nerve signal transmission, understanding which fibers are most vulnerable becomes critical. The science demonstrates that our most sensitive neural pathways, the very ones this early research identified as essential for sensory function, may be the first to suffer when exposed to the electromagnetic pollution that now surrounds us daily.

Finding

We therefore conclude that "C" fibers carry afferent impulses capable of producing reflex effects in cats.

In their words

“We therefore conclude that "C" fibers carry afferent impulses capable of producing reflex effects in cats.”

Figures from the Original Paper

Diagrams extracted from the original research document.

diagramPage 2 - Fig. 1 (above). Pneumograph tracing and electroneurogram during stimulation of cat's saphenous nerve.
p. 2 of the original PDF
diagramPage 4 - Figure 3 illustrates the effect of compression on the electroneurogram of excised cat's saphenous nerve, showing 'A' and 'B' elevations before compression, complete elimination by compression ('C' strength shock), and a slight delay in 'C' elevation when 'A' and 'B' have been eliminated.
p. 4 of the original PDF
graphPage 5 - AI-described figure: Figure 4 illustrates blood pressure and pneumograph tracings during stimulation of a cat's saphenous nerve under dial anesthesia, showing the effects before and after compression with a pressure chamber.
p. 5 of the original PDF

Exposure Information

Specific exposure levels were not quantified in this study.

Cite This Study
DEAN CLARK, JOSEPH HUGHES, HERBERT N. GASSER (1935). AFFERENT FUNCTION IN THE GROUP OF NERVE FIBERS OF SLOWEST CONDUCTION VELOCITY.
Show BibTeX
@article{afferent_function_in_the_group_of_nerve_fibers_of_slowest_conduction_velocity_g5590,
  author = {DEAN CLARK and JOSEPH HUGHES and HERBERT N. GASSER},
  title = {AFFERENT FUNCTION IN THE GROUP OF NERVE FIBERS OF SLOWEST CONDUCTION VELOCITY},
  year = {1935},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

C fibers are the slowest-conducting nerve fibers in your body, lacking the protective myelin sheath that speeds up other nerves. This 1935 study proved they carry important sensory information, making them potentially vulnerable to electromagnetic interference.
Clark used three methods in cats: comparing weak versus strong electrical stimulation, blocking faster A and B fibers while testing C fibers alone, and using mechanical stimulation after blocking the faster fibers.
Unlike A and B fibers, C fibers lack myelin, the fatty protective coating that speeds nerve transmission. This makes them slower but also potentially more vulnerable to external electromagnetic interference.
The study demonstrated that stimulating C fibers alone could trigger measurable reflex responses in cats, proving these slow fibers carry meaningful sensory information to the nervous system for processing.
This study identified the basic function of C fibers, the same vulnerable, unmyelinated nerve pathways that current research suggests may be most susceptible to disruption from wireless radiation and electromagnetic fields.