Study type: Medical/biological study (experimental study, theoretical study)

Do weak, low pulsed frequency, high-frequency electromagnetic or magnetic fields alter the basic bioelectrical parameters of nerve cells in vineyard snails (Helix pomatia L.) ? / I. Electromagnetic fields med./bio.

By: Kullnick U
Published in: Bioelectrochem Bioenerg 1995; 37 (1): 39-45
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Aim of study (acc. to author)

To investigate resting potentials of the vineyard snail (Helix pomatia) to find how they were influenced by weak, low pulsed frequency, high-frequency electromagnetic fields. The flux densities of the fields were chosen such that thermal effects could not occur in the tissue exposed. An experimental method was developed which allowed electrophysiological measurements to be carried out in the high-frequency electromagnetic field without artifacts.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 150 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min
Exposure 2: 150 MHz
Modulation type: pulsed
Exposure duration: continuous for 20 min or intermittent for 2 x 10 min
Exposure 3: 150 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min

Exposure 1

Main characteristics
Frequency 150 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type pulsed
Repetition frequency 8.3 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 2 cm
Chamber A small Plexiglas vessel was attached to a vibration-damped marble slab in a Faraday cage.
Setup The transmitting antenna was fastened 2 cm away from the ganglion.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 50 µT - - - ± 50%
magnetic flux density 70 µT - - - ± 50%
magnetic flux density 90 µT - - - ± 50%
magnetic flux density 124 µT - - - ± 50%

Exposure 2

Main characteristics
Frequency 150 MHz
Type
Exposure duration continuous for 20 min or intermittent for 2 x 10 min
Modulation
Modulation type pulsed
Repetition frequency 8.3 Hz
Exposure setup
Exposure source
Additional info The run down of 40 min served as a run up for the second exposure.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 124 µT - - - ± 50%
power density 0.02 mW/cm² - - - ± 50%

Exposure 3

Main characteristics
Frequency 150 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type pulsed
Additional info

pulse rates of 6, 10, 12, and 50 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 124 µT - - - ± 50%

Reference articles

  • Kullnick U (1992): Influence of weak non-thermic high-frequency electromagnetic fields on the membrane potential of nerve cells

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The resting potential of the neurons being investigated hyperpolarized. A relationship between the resulting value of the strength of the field-induced hyperpolarization and the resting potential before the start of the exposure was established. A model of the sequence of events for the effect was developed in order to explain the exposure-induced hyperpolarization. Fundamental to the hypothesis which was drawn up is the interaction of a possible field-induced release of calcium from intracellular depots in the cytoplasma of neurons and the resultant activation of the calcium-dependent potassium channels.

Study character:

Study funded by

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