Association between Rhythmic Variations of Mouse Body Temperature with 4-16-Minute Periods and Geomagnetic Undulations in Corresponding Frequency Range Pc5/Pi3.

The rhythmic variations of body temperature in two groups of mice located in Moscow and Novosibirsk were compared with geomagnetic undulations within Pc5/Pi3 (1-5 mHz) range measured in Borok and Novosibirsk middle-latitude geophysical observatories located at the same longitudes as the examined mice. The spectral maxima of geomagnetic undulations and body temperature variations were observed with greatest probability at the frequencies of 1.6, 2.3, and 3.1 mHz. At this, the mean square of the distance between the frequencies of spectral maxima of simultaneous oscillations was smaller than that of random intervals favoring the hypothesis on geomagnetic undulations as the synchronizer of biorhythms. In both groups of mice, the share of intervals with a high spectral coherency between geomagnetic undulations and body temperature variations had common maximum in the pre-midnight sector of local time and it was higher for the large-scale geomagnetic undulations. Dependence of geomagnetic undulations on spatial scale suggests that body temperature is affected by electrotelluric field.