Research Paper Volume 8, Issue 10 pp 2370—2391

Figure 4. Sleep fragmentation was greater in older mice and older females slept less compared to younger ones. (A) On average, older female mice (ages 28 and 32 months) slept less than 20-month-old females (p = 0.029, p = 0.0003, respectively) and 32-month-oldfemales slept less than 4-month -old females (p = 0.001). 4-month -old females did not differ from 20-month-old females or 28-month -old females (p >0.999, p = 0.068, respectively), and 28-month -old females did not differ from 32-month-olds (p = 0.796) in the amount of time spent sleeping. (B) Male mice did not show age differences in total amount of sleep measured over a 24-hour period (p = 0.40). (C) Sleep fragmentation was greater in older females (ages 28 and 32 months) than in 4-month -old females (p = 0.0006, p < 0.0001, respectively) and 20-month-old females (p = 0.036, p = 0.001, respectively). Sleep fragmentation did not differ between 28 and 32-month-old (p >0 0.999). (D) Sleep fragmentation was greater in older male mice (p = 0.028); however, in pair-wise comparisons only 4-month and 32-month-old males were significantly different (p = 0.030). Post-hoc tests subject to Bonferroni correction for multiple comparisons. Females n = 20, 20, 30 and 27 for 4, 20, 28 and 32 months. Males n = 18, 18, 26 and 23 for 4, 20, 28 and 32 months.