Physiologic effects of electroanesthesia
Sanford J. Larson, Anthony Sances, Jr. · 1968
1968 research proved electrical fields can alter brain function and consciousness, establishing the biological basis for EMF health concerns.
Plain English Summary
This 1968 study by Larson examined how electrical currents affect the nervous system during electroanesthesia, focusing on brain wave activity in visual and auditory regions. The research explored how extremely low frequency electrical fields influence neural transmission and sensory processing. This early work helped establish scientific understanding of how external electrical fields can alter normal brain function.
Why This Matters
This pioneering research from 1968 represents some of the earliest scientific documentation that electrical fields can directly alter brain function. The study examined electroanesthesia, a medical technique that uses electrical currents to induce unconsciousness, providing clear evidence that external electromagnetic fields can interfere with normal neural transmission. What makes this particularly relevant today is that the extremely low frequency fields studied here are similar to those emitted by our electrical grid and many household appliances.
The science demonstrates that if electrical fields can reliably alter consciousness and sensory processing in controlled medical settings, we should take seriously the potential for everyday EMF exposures to affect brain function in subtler ways. While your home's electrical fields are much weaker than those used in electroanesthesia, the principle remains the same: external electromagnetic fields can influence how your nervous system operates.
Figures from the Original Paper
Diagrams extracted from the original research document.
Exposure Information
Specific exposure levels were not quantified in this study. Duration: 30 minutes
Study Details
To investigate the mechanism and physiologic effects of electrical anesthesia, particularly focusing on cortical versus subcortical effects.
Squirrel monkeys (Saimiri sciureus) and stump-tail macaque monkeys (Macaca spectosa) were used. Elec...
As the level of the applied currents was raised, the amplitude of the cortical somatosensory potenti...
The findings indicate that evoked somatosensory, visual, and auditory potentials as well as recruiting responses are more profoundly affected by the electroanesthesia currents at cortical than at subcortical levels. The parallel disappearance of responsiveness and of cortical-evoked responses suggests that electroanesthesia is largely a cortical phenomenon. Although the currents appear to act at the cortical level, the mechanism is not clear. Since pulses of relatively high frequency are used for electroanesthesia, it appears likely that synaptic mechanisms may be affected. This explanation is supported by theoretical considerations and by the changes in the observed number of synaptic vesicles near the cleft during the application of currents. Spreading depression does not appear to be a likely explanation for electroanesthesia, since the recovery time for evoked potentials is short and the impedance values do not change significantly. The observations to date have not shown adverse metabolic effects. Arterial pCO2 and pH values do not change appreciably from those determined under very light ether anesthesia. In addition, the free fatty acid concentration, which reflects blood catecholamine levels, is not significantly altered. The stability of the impedance values during electroanesthesia suggests that hypoxia does not occur. Conceivably, the currents used for electrical anesthesia in animals may only affect the response to pain rather than to pain perception. However, the disappearance of cortical recruiting responses and of somatosensory, visual, and auditory potentials suggests that cortical processing of afferent impulses is markedly affected. Animals given electroanesthesia repeatedly and without premedication or supplemental agents do not struggle or attempt to escape when the electrodes are applied, as would be expected if the previous experiences had been unpleasant. The observations reported suggest that electrical anesthesia in animals is reversible and safe. The cerebral cortex appears to be more greatly affected than subcortical structures. However, additional physiologic, morphologic, and chemical studies must be done before the safety of the method can be considered proved.
Show BibTeX
@article{physiologic_effects_of_electroanesthesia_g5694,
author = {Sanford J. Larson and Anthony Sances and Jr.},
title = {Physiologic effects of electroanesthesia},
year = {1968},
}