Study type: Medical/biological study (experimental study)

Extremely low frequency magnetic field effects on premorbid behaviors produced by cocaine in the mouse. med./bio.

Published in: Bioelectromagnetics 2004; 25 (4): 245-250

Aim of study (acc. to author)

The effects of exposure to 2-60 Hz magnetic fields on cocaine-induced behavioral changes in mice should be investigated.

Background/further details

In previous experiments, the authors found that magnetic field exposure might influence the toxicity and the behavioral effects of cocaine in mice. The latter should be closer investigated in this study in view of a possible therapeutic use.
216 mice received intraperitoneal injections of cocaine hydrochloride (either 65 or 70 mg/kg) and were exposed to a magnetic field immediately thereafter. The following groups were used (n=24 each): 65 mg/kg cocaine (n=12) and 70 mg/kg cocaine (n=12) and exposure to a magnetic field of 1) 2 Hz, 2) 3 Hz, 3) 4 Hz, 4) 8 Hz, 5) 10 Hz, 6) 15 Hz, 7) 25 Hz, 8) 60 Hz and 9) sham exposure.
The doses of cocaine were chosen because the lethality is around 50%.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2 Hz
Exposure duration: about 20 min
Exposure 2: 3 Hz
Exposure duration: about 20 min
Exposure 3: 4 Hz
Exposure duration: about 20 min
Exposure 4: 8 Hz
Exposure duration: about 20 min
Exposure 5: 10 Hz
Exposure duration: about 20 min
Exposure 6: 15 Hz
Exposure duration: about 20 min
Exposure 7: 25 Hz
Exposure duration: about 20 min
Exposure 8: 60 Hz
Exposure duration: about 20 min

Exposure 1

Main characteristics
Frequency 2 Hz
Type
Waveform
Exposure duration about 20 min
Exposure setup
Exposure source
Chamber plexi glass cage of 18 x 13 x 13 cm³
Setup 5 rectangular coils on 38 x 26 x 38 cm3 with 150 turns on open wooden frames created the fields; 4 vertical wooden supports held the coils, which were set 9.5 cm apart; the homogeneity over the exposed region inside the frame was larger than 95%; mouse cage with one mouse was placed at the center of the coil system; temperature of laboratory was between 26°C and 28°C
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.81 mT minimum measured - -
magnetic flux density 1.83 mT maximum measured - -

Exposure 2

Main characteristics
Frequency 3 Hz
Type
Waveform
Exposure duration about 20 min
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.74 mT minimum measured - -
magnetic flux density 1.82 mT maximum measured - -

Exposure 3

Main characteristics
Frequency 4 Hz
Type
Waveform
Exposure duration about 20 min
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.86 mT maximum measured - -
magnetic flux density 1.81 mT minimum measured - -

Exposure 4

Main characteristics
Frequency 8 Hz
Type
Waveform
Exposure duration about 20 min
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.72 mT maximum measured - -
magnetic flux density 1.68 mT minimum measured - -

Exposure 5

Main characteristics
Frequency 10 Hz
Type
Waveform
Exposure duration about 20 min
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.65 mT maximum measured - -
magnetic flux density 1.6 mT minimum measured - -

Exposure 6

Main characteristics
Frequency 15 Hz
Type
Waveform
Exposure duration about 20 min
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.8 mT maximum measured - -
magnetic flux density 1.75 mT minimum measured - -

Exposure 7

Main characteristics
Frequency 25 Hz
Type
Waveform
Exposure duration about 20 min
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.98 mT maximum measured - -
magnetic flux density 1.86 mT minimum measured - -

Exposure 8

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration about 20 min
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.99 mT maximum measured - -
magnetic flux density 0.96 mT minimum measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

It was found that the mean onset times of stop rearing and tonic-clonic seizures were significantly different in the 4 Hz magnetic field exposure group (group 3) compared to the sham exposure group.

Study character:

Study funded by

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