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Fig. 1 | Biology of Sex Differences

Fig. 1

From: Sex differences in variability across timescales in BALB/c mice

Fig. 1

Males exhibit more daily variability than females. Median 4-day plots of locomotor activity (LA; a) and core body temperature (CBT; c) for all females and males, from 12 days of 13 mice each; the light:dark cycle is shown along the abscissa. Day 1 is the day of estrus for females, with arbitrarily selected four consecutive days shown for males for comparison. Females show expected 4-day cycles of LA and CBT that are absent in males. Box plots of the daily variability comparing females to males (b, d) reveal that males have a higher intra-animal daily range in LA and CBT. Plus symbol indicates outliers. Asterisk indicates a significant sex difference (without estrus, LA: p < 1 × 10−4; CBT: p = 1 × 10−4; with estrus, LA: p < 1 × 10−4; CBT: p < 1 × 10−4). Males also exhibit a wider population range in CBT, but the population range in LA is comparable for both sexes. The two plots on the right indicate that, whereas estrus changes the structure of both variables across the day, it does not increase the overall range of either variable in females (all days including estrus, LA: p = 1 × 10−4; CBT: p < 1 × 10−4). Males appear to show higher amplitude, high frequency oscillation in the inactive (light) phase

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