Study type: Medical/biological study (experimental study)

Daily repeated magnetic field shielding induces analgesia in CD-1 mice med./bio.

Published in: Bioelectromagnetics 2005; 26 (2): 109-117

Aim of study (acc. to author)

This study was performed to investigate the effects of magnetic field shielding on analgesia in mice.
Three objectives were targeted: 1) Whether a daily 1 h magnetic field shielding, repeated on 10 consecutive days affect analgesia in mice. 2) If possible shielding effects depend rather on magnetic field than on ambient electric field. 3) To determine if possible shielding effects are consistent with opioid mediated analgesia.

Background/further details

The magnetic field shielding was achieved by the use of special Mu-metal (TM) material.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 0–100 Hz
Exposure duration: repeated daily exposure, 1 h/day for 10 consecutive days

Exposure 1

Main characteristics
Frequency 0–100 Hz
Type
Waveform
Exposure duration repeated daily exposure, 1 h/day for 10 consecutive days
Exposure setup
Chamber Mu-metal enclosures (33 x 38 x 20 cm³) made of 1 mm Mu metal and laminated with 5 mm thick opaque Plexiglas
Setup mice were placed individually in a translucent acrylic cage (26 x 16 x 12 cm³) which was placed in the Mu-metal enclosure
Sham exposure A sham exposure was conducted.
Additional info The sham enclosures (33 x 38 x 20 cm) were made of 5 mm thick black opaque Plexiglas. Acrylic mouse colony cages were used for holding individual mice inside sham enclosures.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 30 nT maximum measured - AC field for the sham (= not shielded) condition
magnetic flux density 55 µT mean measured - Static magnetic field measured in the sham exposure enclosure

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

A robust effect on analgesia depending on magnetic field shielding was observed. The maximum analgesic response occured over days 4-6 of the experiment. The effect seems to be opioid related as indicated by experiments using morphine and naloxone.

Study character:

Study funded by

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