Figure 1
From: Stress-induced sleep-like inactivity modulates stress susceptibility in mice
Social defeat stress induces sleep-like inactivity with decreased body temperature. (a) A behavioral schedule. On the baseline day, mice implanted with a small acceleration and temperature sensor in their abdominal cavity were left undisturbed in their home cages. On the prestress day, they received habituation to the behavioral chamber used in the social interaction test without an ICR target mouse (“Target (−)”) at ZT 13–15. On the stress day, they received social defeat stress for 10 min for stressed mice without (N = 13) or with (N = 9) sleep deprivation for 6 h (ZT 12–18) (“Stress” or “Stress + Sleep dep”, respectively), or cage transfer for 10 min (N = 6, “Control”) just prior to ZT 12. On the poststress day, they received the social interaction test with an ICR target mouse (“Target (+)”) at ZT 13–15. The values during ZT 16–24 on the poststress day are missing in 3 control mice, 3 stressed mice and all stressed mice with sleep deprivation. (b) Time course plots of the proportion of active periods (above) and the core body temperature in each one-hour bin (below). (c) The core body temperature during either cage transfer (“Control”) or social defeat stress (“Stress”) on the Stress day and during the same ZT on the Baseline day. Note that the data with the stress are combined from both the “Stress” and “Stress + Sleep dep” groups, as the two groups were treated the same before sleep deprivation. (d) Mean values of the proportion of active periods (left) and the core body temperature (right) during ZT 13–15. Note that the arrowhead indicates one of the stressed mice with severe hypothermia, which was excluded from statistical analyses for the body temperature. (e) The relationship between the proportion of active periods and core body temperature during ZT 13–15. The solid and dotted lines indicate linear regression lines and their 95% confidence intervals for the respective behavioral conditions. One of the stressed mice with severe hypothermia was excluded from linear regression analysis for the stressed mice. (f) Time course plots of the proportion of active periods (above) and the core body temperature (below) in each one-hour bin for individual mice shown in (b). Values are expressed as means ± SEM. **P < 0.01; ***P < 0.001; ns, not significant for Tukey’s multiple comparisons test following one-way ANOVA.
