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Super-high Frequency Electric Field and Crustacean Ganglionic Discharges

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Itsuo Yamaura, Shiko Chichibui · 1967

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High-power 11 GHz microwaves suppressed nerve firing in crustaceans, with stronger radiation causing faster suppression.

Plain English Summary

Summary written for general audiences

Researchers exposed crayfish and prawn nerve clusters to 11 gigahertz microwave radiation at an available power of 100 W/mm². The microwaves suppressed normal nerve firing patterns, with stronger radiation causing faster suppression. This 1967 study provided early evidence that microwave radiation can directly disrupt nervous system function in living organisms.

Why This Matters

This pioneering 1967 research demonstrated that microwave radiation can directly interfere with nervous system function at the cellular level. The study used 11 GHz frequency, which falls within the range of modern radar and satellite communications. The available power of 100 W/mm² is extremely high compared to typical consumer exposures, but the linear relationship between radiation intensity and nerve suppression suggests biological effects occur across a spectrum of exposures. What makes this research particularly significant is that it showed both immediate suppression of nerve activity and a following supernormal phase of increased firing, indicating that microwave effects on the nervous system aren't just about heating tissue. The researchers discussed possible thermal and non-thermal mechanisms, a distinction that remains central to EMF health debates today. While we can't directly extrapolate from crustacean nerve responses to human health effects, this study established fundamental principles about how electromagnetic fields interact with nervous tissue that have been confirmed in countless subsequent studies.

Figures from the Original Paper

Diagrams extracted from the original research document.

diagramPage 2 - AI-described figure: Block diagram of the experimental arrangement for microwave irradiation on crustacean nerve ganglia.
p. 2 of the original PDF
diagramPage 3 - AI-described figure: Fig. 2: Spontaneous discharges from a crayfish ganglion showing control and post-irradiation patterns.
p. 3 of the original PDF
graphPage 4 - Fig. 3: Microwave irradiation effect on the crayfish ganglion showing impulse frequency change by irradiation and a schematic of frequency change with percentage scale.
p. 4 of the original PDF
graphPage 5 - AI-described figure: Fig. 4: Beat type discharge from a crayfish ganglion showing impulse frequencies per every 2 seconds plotted against time in seconds.
p. 5 of the original PDF
graphPage 6 - AI-described figure: Fig. 5: Experiment on the prawn ganglion showing impulse frequencies plotted in a logarithmic scale against time.
p. 6 of the original PDF
graphPage 7 - AI-described figure: Fig. 6: Attenuator effect on crayfish ganglionic discharge with impulse frequencies and durations of microwave irradiation.
p. 7 of the original PDF
Cite This Study
Itsuo Yamaura, Shiko Chichibui (1967). Super-high Frequency Electric Field and Crustacean Ganglionic Discharges.
Show BibTeX
@article{super_high_frequency_electric_field_and_crustacean_ganglionic_discharges_g5667,
  author = {Itsuo Yamaura and Shiko Chichibui},
  title = {Super-high Frequency Electric Field and Crustacean Ganglionic Discharges},
  year = {1967},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

Researchers used 11 gigahertz (GHz) microwave radiation, which falls in the super-high frequency range used for radar and satellite communications today.
The available power was 100 W/mm², which is extremely high compared to typical consumer device exposures from phones or WiFi.
In one crayfish ganglion, a 100 W/mm² irradiation reduced the discharge frequency with a time constant of 2.3 seconds, and with an attenuator that halved the electric field intensity the time constant became longer (4.9 seconds). The time constant of the declining limb in the suppressed phase had a linear relation to the intensity of microwave radiation, so higher power produced faster suppression.
The researchers discussed possible thermal (heating) and non-thermal mechanisms for the two phases. A calculated temperature rise of 0.24°C in a ganglion over 10 seconds led them to conclude that at least the suppressed phase is not directly related to the thermal conversion of absorbed energy.
The microwaves caused two distinct phases: immediate suppression of nerve impulses, followed after irradiation ended by a supernormal phase, a temporary increase in impulse frequency.