PERIOD SHORTENING AND PHASE-SHIFTING EFFECTS OF ETHANOL ON THE GONYAULAX GLOW RHYTHM

In a number of organisms which exhibit circadian rhythmicity, a continuous exposure to ethanol at moderate (0.1%) concentrations is known to cause period lengthening. In studies of the effects of ethanol on the circadian luminescence glow rhythm of the marine dinoflagellate Gonyaulax, we observed that 0.1% ethanol causes instead a period shortening. We have also found that ethanol pulses cause phase shifts, with little or no after-effects on the period of the circadian rhythm which continues thereafter. © 1979 Springer-Verlag.