Magnetic fields abolish nychthemeral rhythmicity of responses of Purkinje cells to the pineal hormone melatonin in the pigeon's cerebellum.
The effects of micro-electrophoretically applied melatonin on the electrical activity of Purkinje cells in the cerebellum of anaesthetized pigeons were studied. The proportion of excitatory and inhibitory responses to the pineal indoleamine varied significantly depending on whether the cells were tested during the day or at night. This day/night rhythm of responses was abolished if the birds were exposed to complete inversion of the vertical component of an artificial earth's strength magnetic field for one hour at 21.00 h. The results are in line with the concept that pineal involvement in endogenous central nervous rhythms is influenced by changes in the earth's magnetic field.
D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D010856:Columbidae / Q000502:physiology*; D055593:Geological Phenomena; D005844:Geology; D008280:Magnetics; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D010870:Pineal Gland / Q000502:physiology; D011689:Purkinje Cells / Q000187:drug effects* / Q000502:physiology
D008550:Melatonin