ISSN:
1432-1351
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Dilute solutions of ethyl alcohol lengthen the free-running period of the endogenous tidal rhythmicity of the isopod, Excirolana chiltoni. One-half percent alcohol increases the period, on the average, by about an hour, and the dosage dependence is apparently linear up to 1% alcohol. Since alcohol has also been shown to slow the circadian leaf-movement rhythm of the bean plant, Phaseolus, to about the same extent, the effects of this substance on endogenous biological clocks may represent a general phenomenon. Both this influence of alcohol, and previously reported effects of D2O on biological clocks are consistent with the hypothesis that the fundamental and general process underlying these endogenous rhythms involves an oscillation in cellular electrochemistry. Attempts to produce period values greater than about 26 hours in the isopods' rhythm, by simultaneous administration of alcohol and heavy water (which also slows the rhythm), were unsuccessful because these two substances interact to produce heavy mortality, at doses which, when given separately, permit good survival. Cycloheximide, which can, under some circumstances, slow the circadian rhythm of Euglena, had no significant effect on the tidal rhythm of Excirolana, at doses up to 3 μg/ml. MS 222, an anaesthetic which slows the high-frequency electric-organ rhythm of the fish, Stenarchus, was similarly without effect on the rhythm of Excirolana, at doses up to 150 μg/ml. Variations in total salinity of the aquarium water, ranging from 50% to 150% that of seawater, were also without a measurable effect on the period of the rhythm, as were variations in the external calcium ion content between 50% and 500% that of seawater, when the osmotic strength was held approximately constant.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00340685
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