Circadian locomotor activity of Musca flies: recording method and effects of 10 Hz square-wave electric fields.
Musca domestica flies that were exposed to a uniform vertical 10 Hz electric square-wave field of 1 kVm(-1) changed the period length of their circadian locomotor activity rhythm. Under constant conditions, the clock of short-period flies was slowed down by the field, whereas the clock of long-period flies either was affected only scarcely (experiments at about 19 degrees C) or ran faster (experiments at 25 degrees C). If the field was applied for only 12 h daily, then 30-40 percent of the flies were synchronized. Thus, the field could function as a weak "Zeitgeber" (synchronizer). If the field was increased to 10 kVm(-1), then 50-70 percent of the flies were synchronized. Flies avoided becoming active around the onset of the 12 h period of exposure to a 10 Hz field. The results of these experiments are discussed with respect to similar experiments by Wever on the effects of exposure to a 10 Hz field on the circadian system of man.
Engelmann
W
W
Institut für Botanik, Physiologische Okologie der Pflanzen, University of Tübingen, Tübingen, Federal Republic of Germany.
Hellrung
W
W
Johnsson
A
A
D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D006793:Houseflies / Q000502:physiology*; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*