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1	Author	T. Kreuels, R. Joerres, W. M. Artin, K. Brinkmann	Requires cookie*
	Title	System Analysis of the Circadian Rhythm of Euglena gracilis, II: Masking Effects and Mutual Interactions of Light and Temperature Responses
	Abstract	Motility o f Euglena gracilis shows free running circadian rhythms. The circadian system is sensitive to light and temperature signals, but it is always m asked by direct responses o f m otility to light (photokinesis) and temperature (therm okinesis). By means o f a com partim ental m odel which defines the interrelations between the pathways o f therm okinesis, photokinesis and the circadian system a unifying view o f effects o f temperature and light input signals is outlined. According to the model, and using double sine input signals the dynam ics o f thermokinesis is described by a differential am plifier with constant gain. Although thermokinesis heavily masks circadian responses to tem perature signals, the lim ited range o f circadian entrainment is indirectly dem onstrated by a lim ited reappearance o f free running circadian oscillations after stopping the tem perature program. Free running circadian oscillations do reappear only after pretreatment with tem perature periods near the circadian eigenperiod. A white mutant lacking photosynthesis is used to investigate the role o f photosynthesis in the signal processing. Although light synchronizes the circadian rhythms o f the white mutant if applied as single input, it does not affect the m otility if applied together with temperature inputs near the circadian eigenperiod. These results indicate frequency dependent m utual interactions between the model compartments.
	Reference	Z. Naturforsch. 39c, 801—8 (1984); received February 2 2 /April 27 1984
	Published	1984
	Keywords	Circadian Rhythm, System Analysis, Euglena gracilis, Masking Temperature Responses
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	TEI-XML for	default:Reihe_C/39/ZNC-1984-39c-0801.pdf
	Identifier	ZNC-1984-39c-0801
	Volume	39