Antinociceptive effects of a pulsed magnetic field in the land snail, Cepaea nemoralis

Pulsed magnetic fields (patent pending) consisting of approximately 100 mu T (peak), frequency modulated, extremely low frequency magnetic fields (ELFMF) were shown to induce a significant degree of antinociception ('analgesia') in the land snail Cepaea nemoralis. Fifteen minute exposures to a specific magnetic field both increased enkephalinase inhibitor induced opioid analgesia and induced analgesia in untreated snails. Injection of the prototypic opioid antagonist naloxone, attenuated, but did not completely block, the pulsed magnetic field induced analgesia. Two other pulsed waveform designs failed to induce analgesia in untreated snails; These findings suggest that specific magnetic field exposure designs may be tailored to produce significant behavioral effects including, but certainly not limited to, the induction of analgesia. (C) 1997 Elsevier Science Ireland Ltd.