Acute Social Defeat Stress Increases Sleep in Mice

Abstract

Social conflict is a major source of stress in humans. Animals also experience social conflicts and cope with them by stress responses that facilitate arousal and activate sympathetic and neuroendocrine systems. The effect of acute social defeat (SoD) stress on the sleep/wake behavior of mice has been reported in several models based on a resident-intruder paradigm. However, the post-SoD stress sleep/wake effects vary between the studies and the contribution of specific effects in response to SoD or non-specific effects of the SoD procedure (e.g., sleep deprivation) is not well established. In this study, we established a mouse model of acute SoD stress based on strong aggressive mouse behavior toward unfamiliar intruders. In our model, we prevented severe attacks of resident mice on submissive intruder mice to minimize behavioral variations during SoD. In response to SoD, slow-wave sleep (SWS) strongly increased during 9 h. Although some sleep changes after SoD stress can be attributed to non-specific effects of the SoD procedure, most of the SWS increase is likely a specific response to SoD. Slow-wave activity was only enhanced for a short period after SoD and dissipated long before the SWS returned to baseline. Moreover, SoD evoked a strong corticosterone response that may indicate a high stress level in the intruder mice after SoD. Our SoD model may be useful for studying the mechanisms and functions of sleep in response to social stress.

Anxiolytic Effect of Increased NREM Sleep after Acute Social Defeat Stress in Mice

“…Animals suffer from social defeat mainly in the active period. However, all previous studies of mice started the social defeat session in the inactive period when the duration of baseline NREM sleep is relatively longer [ 11 – 13 ]. In reality, stressful events are more likely to occur in the active period.…”

“…Social stress also leads to sleep disturbances [7][8][9][10]. Interestingly, in contrast to the wellstudied effect of stress on anxiety-like behaviors, the consequences of social defeat stress (SDS) on sleep are not clear [10][11][12][13][14]. An acute effect of SDS on sleep has been reported in different studies using different SDS procedures and standards of comparison.…”

“…An acute effect of SDS on sleep has been reported in different studies using different SDS procedures and standards of comparison. For example, the results of investigating whether wakefulness or sleep time is increased in the first 3 h after SDS are contradictory in two recently-published studies [ 11 , 15 ]. On the other hand, sleep disturbances are recognized as symptomatic of anxiety disorders [ 16 – 18 ].…”

Sleep in Drosophila and Its Context

“…In humans, sleep abnormalities have been reported in patients with posttraumatic stress disorder (Kobayashi et al, 2007), and insomnia is present in 80% of patients with depression (Armitage, 2007). Likewise, in mice, both acute (Fujii et al, 2019) or chronic (Henderson et al, 2017; Olini et al, 2017) socially induced stress produces an increase in sleep after the encounter.…”

Spatial Nano-Morphology of the Prolamellar Body in Etiolated Arabidopsis thaliana Plants With Disturbed Pigment and Polyprenol Composition

“…The paracrystalline PLB structure is determined by its specific composition; however, the role of only several components of the internal etioplast network in the formation and maintenance of such unique cubic arrangement has been identified so far. The crucial role of polar lipids -monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) in this process was recently shown by Fujii et al (2017Fujii et al ( , 2018Fujii et al ( , 2019 using dgd1 mutant and DEX-inducible amiR-MGD1 line. It was proposed already in earlier studies, that the proper MGDG/DGDG ratio could play a role in the PLB organization (Selstam and Sandelius, 1984).…”