REPEATED MAGNETIC FIELD SHIELDING INDUCES ANALGESIA IN MICE.

Behavioural effects related to the Earth’s geomagnetic field, such as orientation, migration route determination, and direction finding, are perhaps the most consistent reported effects of exposure to magnetic fields. As well, acute exposure to a weak electromagnetic field has been shown to interrupt this behaviour, and attenuate opioid-induced analgesia. Here we show that 10 days of daily repeated 1 hour exposures of mice to the environment produced by a µ-metal box (geomagnetic field attenuated by a factor of ~125) induces significant analgesia (160 % of sham exposed) that peaks at day 5 and abates by day 10