Concepts in human biological rhythms

Figures & data

Figure 1. Aspects of the human temporal organization: physiological functions of the cardiovascular system. The acrophase (Φ) location (blue circles) of any of the considered rhythms is not randomly distributed over 24 h. On the contrary, acrophases represent physiologically validated temporal relationships. The healthy young human adults' synchronization was approximately 16 h of diurnal activity and 8 h of nocturnal rest. Reproduced from reference 26: Reinberg A. Chronobiologie Médicale, Chronothérapeutique. Paris, France: Flammarion Médecine-Sciences: 2003. Copyright © 2003, Flammarion Médecine-Sciences.

Figure 2. Distributions of circadian rhythm acrophases (Φ) according to the variables' function. A to G illustrate the 24-h acrophase frequency distribution of 7 groups of variables, and the dendrogram H shows the similarities along the groups by clusters on correlation scale (r). The upper cluster in H presents the greater similarities among the physiological variables (A), cognitive function (B), and hormones (C), where most of the acrophases occur in the late afternoon. In the inorganic molecules (D) and the organic molecules (E) groups (middle cluster H), most acrophases aggregate around midday. The third cluster (lower cluster, H) contained cellular components (F) and enzymes (G), in which most acrophases were distributed around midnight. Reproduced from reference 24: Ticher À, Ashkenazi IE, Reinberg A. Preservation of the functional advantage of human time structure. FASEBJ. 1995;9:269-272. Copyright © 2003, Federation of American Societies for Experimental Biology.

Figure 3. Prominent circadian period x resulting from power spectra analyses of longitudinal time series for 39 subjects. Prominent is for all of the variables and subjects were plotted for each of the four groups and their tolerance to shift work. Gray circles, oral temperature; blue triangles, right-hand grip strength; gray triangles, left-hand grip strength. Reproduced from reference 63: Reinberg A, Motohashi Y, Bourdeleau P, Andlauer P Levi F, Bicakova-Rocher A. Alteration of period and amplitude of circadian rhythms in shift workers with special reference to temperature, right and left hand grip strength. Eur J Appi Physiol. 1988:57:1 5-25. Copyright © 1988, Springer-Verlag.

Figure 4. Periods of oral temperature rhythm: frequency distribution in Caucasian-French (CF) and Asiatic-Japanese (AJ) subjects. The CF distribution includes theτ frequency distribution of 78 individuals was extracted from data of Ashkenazi et al.¹⁶ In both CF and AJ populations, the 0.8 h deviation unit was found to reach a higher degree of statistical significance, with P<0.02 to P<0.Q004 according to tests. Reproduced from reference 68: Motohashi Y, Reinberg AE, Ashkenazi IE, Bikcakova-Rocher A. Genetic aspects of circadian dyschronism: comparison between Asiatic-Japanese and Caucasian-French populations. Chronobiol Int. 1995;12:324-332. Copyright © 1995, Marcel Dekker.

AshkenaziIE.ReinbergA.Bicakova-RocherA.TicherA.The genetic background of individual variations of circadian rhythm period in healthy human adults.Am J Hum Genet.199352125012598503453

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