Pineal gland “magnetosensitivity” to static magnetic fields is a consequence of induced electric currents (eddy currents)

Alexander Lerchl, Keico O. Nonaka, Russel J. Reiter

Research output: Contribution to journalArticlepeer-review

136 Scopus citations


Abstract: During the past decade, a number of reports indicated that the mammalian pineal gland is magnetosensitive in terms of spatial orientation. This indication is based on observations that artificial alterations of the direction of the earth's magnetic field (MF) markedly decreased the gland's capability to synthesize melatonin. These findings, however, seem paradoxical since animals as well as humans experience such alterations whenever they turn their heads. Therefore, the potential of the pineal for sensing magnetic fields was re‐investigated. During the dark phase, rats were exposed to repeatedly inverted MFs, generated by two identical pairs of Helmholtz coils; one pair connected to a power supply automatically, the other pair manually using an integrated potentiometer. Only the pineals of animals exposed to the automatically activated field responded with a reduced activity of the rate‐limiting enzyme serotonin‐N‐acetyltransferase, lower melatonin levels and increases in serotonin and 5‐hydroxyindole acetic acid. Hence, MF exposure itself did not affect the pineal. Rather, induced eddy currents in the animals, resulting from rapid On/Off transients of the artificially applied MF, are most likely the explanation.

Original languageEnglish (US)
Pages (from-to)109-116
Number of pages8
JournalJournal of pineal research
Issue number3
StatePublished - Apr 1991


  • electromagnetic fields‐melatonin
  • serotonin‐5‐hydroxyindole acetic acid
  • serotonin‐N‐acetyltransferase

ASJC Scopus subject areas

  • Endocrinology


Dive into the research topics of 'Pineal gland “magnetosensitivity” to static magnetic fields is a consequence of induced electric currents (eddy currents)'. Together they form a unique fingerprint.

Cite this