Figure 3. Period Changes (+ SEM) Observed in the Free-Running Rhythm of Wild-Type Flies after Application of Magnetic Fields under Blue Light and Red Light Illumination.

Under blue light (A), magnetic fields of different strength were applied, and ANOVA revealed that the observed period alterations significantly depended on the strength of the magnetic field (F_3,101 = 3.0; p = 0.03). A post-hoc test revealed that the period change at 300 μT was significantly different from that at 0 μT. Under red light (B), the period alterations produced by a magnetic field of 300 μT were not significantly different from those occurring spontaneously (without a magnetic field). Numbers in the columns indicate the number of included flies. Flies that became arrhythmic are excluded from this analysis (compare Table 1).