Study type: Medical/biological study (experimental study)

Weak extremely-low-frequency magnetic field-induced regeneration anomalies in the planarian Dugesia tigrina. med./bio.

Published in: Bioelectromagnetics 1996; 17 (6): 467-474

Aim of study (acc. to editor)

To study the effect of weak extremely low frequency magnetic fields on regeneration anomalies in the planarian Dugesia tigrina.

Background/further details

The authors recently reported (publication 2870) that cephalic regeneration in the planarian Dugesia tigrina was significantly delayed in populations exposed continuously to combined parallel DC (78.4 µT) and AC (60 Hz, 10µT) magnetic fields. This effect was consistent with hypotheses suggesting an underlying resonance phenomenon.
The turbellarian flatworm Dugesia tigrina is of particular research importance since it embodies a large number of stem cells in its connective tissue which, after injuries or lesions, can differentiate into new nerves, muscles, sensory organs, and other tissues. Due to its regeneration ability the planarian plays an important role in regeneration research.
Transverse lesions were made immediately posterior to the auricles (before exposure).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: 12 days continuous exposure, except approx. 1 hour each day for observations, calibration and measurements
Faraday control
Exposure 2: 60 Hz
Exposure duration: 12 days continuous
Exposure 3: 60 Hz
Exposure duration: 12 days continuous
Exposure 4:
Exposure duration: 12 days continuous
Ambient
Exposure 5:
Exposure duration: 12 days continuous
Passive control

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration 12 days continuous exposure, except approx. 1 hour each day for observations, calibration and measurements
Additional info Faraday control
Exposure setup
Exposure source
Setup 3 identical solenoids, each 24 cm apart and horizontally aligned, were centered in a triple-axis Helmholtz coil system; an AC signal was fed to the first solenoid that was connected in series to a matching set of windings in the second solenoid; an additional DC signal was fed to a second set of windings of these solenoids; a third solenoid was placed between these two
Additional info in the first coil the resulting field consisted only of the AC component; in the second coil resulted a combination of AC and DC magnetic field; in the third coil the horizontal component of the geomagnetic field and a residual AC field of 0,2 µT existed
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.01 µT cf. remarks measured - vertical DC field +/- 0.1 µT
magnetic flux density 0.01 µT cf. remarks measured - horizontal DC field +/- 0.05 µT
magnetic flux density 1 µT peak value measured - AC field
magnetic flux density 10 µT peak value measured - AC field
magnetic flux density 40 µT peak value measured - AC field
magnetic flux density 51.1 µT peak value measured - AC field
magnetic flux density 78.4 µT peak value measured - AC field

Exposure 2

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration 12 days continuous
Additional info Calcium Resonance
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.01 µT cf. remarks measured - vertical DC field +/- 0.1 µT
magnetic flux density 1 µT peak value measured - AC field
magnetic flux density 10 µT peak value measured - AC field
magnetic flux density 40 µT peak value measured - AC field
magnetic flux density 78.4 µT peak value measured - AC field
magnetic flux density 78.42 µT cf. remarks measured - horizontal DC field +/- 0.18 µT

Exposure 3

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration 12 days continuous
Additional info Potassium resonance
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.05 µT cf. remarks measured - vertical DC field +/- 0.05 µT
magnetic flux density 51.13 µT cf. remarks measured - horizontal DC field +/- 0.12 µT
magnetic flux density 51.1 µT peak value measured - AC field

Exposure 4

Main characteristics
Frequency
Type
Waveform
Exposure duration 12 days continuous
Additional info Ambient
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 53.5 µT cf. remarks measured - vertical DC field +/- 0.01 µT
magnetic flux density 18.2 µT cf. remarks measured - horizontal DC field +/- 0.01 µT

Exposure 5

Main characteristics
Frequency
Type
Exposure duration 12 days continuous
Additional info Passive control
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.01 µT cf. remarks measured - vertical DC field +/- 0.1 µT
magnetic flux density 18.2 µT cf. remarks measured - horizontal DC field +/- 0.01 µT

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
  • head
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The data showed that weak extremely low frequency magnetic fields can significantly increase the incidence of regeneration anomalies in cephalically regenerating planaria. The magnitude of the response increased as a function of AC field intensity. Similar to regeneration rate effects, the incidence of regeneration anomalies was specifically dependent upon the planaria possessing a fixed orientation with respect to the applied magnetic field vectors.
The results suggest that cephalic regeneration in the planarian represents an excellent model system for investigating teratogenic effects of weak extremely low frequency magnetic fields.

Study character:

Study funded by

Related articles