Neural function and behavior: defining the relationship

Abstract

Over the years, this laboratory has studied radio-frequency (rf) energy effects, such as evoked potentials in the brains of cats, conditioned responses in cats and monkeys, frog heart arrhythmia, and hearing phenomena in cats and humans. A few years ago, one of us (A.H.F.) discussed the possible mechanisms by which rf energy could affect biologic systems in general and the nervous system in particular. The possibilities considered and evaluated included rf energy-induced transmembrane potential changes, conformational changes in membranes, field-induced forces at the neural junction, microthermal effects, and also possible rf effects on tissue thought to have electret characteristics or piezoelectric properties. The solid-state characteristics of the nervous system were regarded within the context of possible rf energy-induced effects, and these possibilities were evaluated. Other possibilities were also contemplated. The evaluation was concluded with the observation that, “The question is not whether there is a possible mechanism, but rather which of numerous possible mechanisms . . . .” In the work reported here, we made a first approach to answering the question and began to define the relationship between neural function and behavior. We have used essentially the same rf energy parameters in experiments that involved avoidance behavior and brain tissue permeability change as indexed with a fluorescent dye. We found an association between changes in behavior and in brain permeability. We have also found a difference in effectiveness of pulsed and continuous energy on behavior and brain permeability. We wish to make quite clear that we have not established a causal relationship, only an association. BEHAVIOR EXPERIMENT In the behavior experiment, we compared pulsed illumination, continuous wave (cw) illumination, and sham illumination effects on rats in a shuttle box. The shuttle box was constructed of white polystyrene, divided in half by a low hurdle. One half was shielded from the rf energy. The dependent variable was the amount of time spent in the rf-shielded half as compared to the unshielded half of the box. The box balanced as a see-saw on a 2 cm high wedge that permitted limited travel. At each end was a microswitch that registered animal location on an Esterline Angus event recorder. The rf energy source was a Microdot model 411A power oscillator that was connected by an RG-8 cable to a model 11-1.1 Scientific Atlanta coax to wave guide adaptor and standard gain horn antenna. The antenna emitted energy into an rf anechoic chamber that was constructed of RF 340 absorber, which minimized spurious reflections and created essentially free field conditions. Prior to each day’s testing, all equipment was turned on, tested, and adjusted.

AI evidence extraction

Main findings

Using essentially the same RF parameters across experiments, the authors report an association between changes in avoidance behavior and changes in brain permeability (fluorescent dye index). They also report a difference in effectiveness between pulsed and continuous-wave RF on behavior and brain permeability, and state they did not establish causality.

Outcomes measured

• Avoidance/position preference behavior in shuttle box (time spent in RF-shielded vs unshielded half)
• Brain tissue permeability change indexed with a fluorescent dye
• Comparison of pulsed vs continuous-wave RF effectiveness on behavior and brain permeability

Limitations

• Causal relationship explicitly not established (association only)
• Frequency, SAR/dose metrics, exposure duration, and sample size not reported in the provided abstract
• Details of results (magnitude/statistics) not provided in the provided abstract

Suggested hubs

• rf-bioeffects (0.9)
  Laboratory RF exposure examining neural/behavioral effects and brain permeability; pulsed vs CW comparison.

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        "frequency_mhz": null,
        "sar_wkg": null,
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    },
    "population": "Rats (behavior experiment); also mentions prior work in cats, monkeys, frogs, and humans",
    "sample_size": null,
    "outcomes": [
        "Avoidance/position preference behavior in shuttle box (time spent in RF-shielded vs unshielded half)",
        "Brain tissue permeability change indexed with a fluorescent dye",
        "Comparison of pulsed vs continuous-wave RF effectiveness on behavior and brain permeability"
    ],
    "main_findings": "Using essentially the same RF parameters across experiments, the authors report an association between changes in avoidance behavior and changes in brain permeability (fluorescent dye index). They also report a difference in effectiveness between pulsed and continuous-wave RF on behavior and brain permeability, and state they did not establish causality.",
    "effect_direction": "mixed",
    "limitations": [
        "Causal relationship explicitly not established (association only)",
        "Frequency, SAR/dose metrics, exposure duration, and sample size not reported in the provided abstract",
        "Details of results (magnitude/statistics) not provided in the provided abstract"
    ],
    "evidence_strength": "insufficient",
    "confidence": 0.61999999999999999555910790149937383830547332763671875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "radio-frequency energy",
        "RF",
        "pulsed",
        "continuous wave",
        "avoidance behavior",
        "rats",
        "brain permeability",
        "fluorescent dye",
        "mechanisms",
        "nervous system"
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            "reason": "Laboratory RF exposure examining neural/behavioral effects and brain permeability; pulsed vs CW comparison."
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