0230 Preimmunization With a Non-pathogenic Bacterium Mycobacterium vaccae NCTC11659 Prevents the Development of Cortical Hyperarousal and a PTSD-like Sleep Phenotype Following Sleep Disruption Plus Acute Stress in Mice.

AbstractBecause regular sleep disruption can increase vulnerability to stress-related psychiatric disorders, there is a need to explore novel countermeasures to increase stress resilience after inadequate sleep. In this study, we explored the impact of 5 days of intermittent sleep disruption on vulnerability to acute social defeat stress in mice, and investigated the ability of the environmental, immunomodulatory bacterium Mycobacterium vaccae NCTC 11659 (MV) to promote stress resilience in that context. We found that mice receiving sleep disruption plus acute stress developed sleep and behavioral phenotypes that had some features of human posttraumatic stress disorder (PTSD) including reduced NREM delta power and increased NREM beta power in post-stress sleep EEG, persistent increases in sleep fragmentation and the REM:Sleep ratio, and behavioral changes. Importantly, immunization with heat-killed MV prevented the development of this phenotype. These results support further research into novel, microbial-based countermeasures to improve health and increase resilience to sleep disruption.

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Immunization with a heat-killed bacterium, Mycobacterium vaccae NCTC 11659, prevents the development of cortical hyperarousal and a PTSD-like sleep phenotype after sleep disruption and acute stress in mice

SLEEP ◽

10.1093/sleep/zsaa271 ◽

2020 ◽

Author(s):

Samuel J Bowers ◽

Sophie Lambert ◽

Shannon He ◽

Christopher A Lowry ◽

Monika Fleshner ◽

...

Keyword(s):

Acute Stress ◽

Social Defeat ◽

Sleep Disruption ◽

Sleep Behavior ◽

Mycobacterium Vaccae ◽

Environmental Bacterium ◽

Object Location Memory ◽

Stress Vulnerability ◽

Negative Impacts ◽

Induced Changes

Abstract Study Objectives Sleep deprivation induces systemic inflammation that may contribute to stress vulnerability and other pathologies. We tested the hypothesis that immunization with heat-killed Mycobacterium vaccae NCTC 11659 (MV), an environmental bacterium with immunoregulatory and anti-inflammatory properties, prevents the negative impacts of five days of sleep disruption on stress-induced changes in sleep, behavior, and physiology in mice. Methods In a 2x2x2 experimental design, male C57BL/6N mice were given injections of either MV or vehicle on days –17, –10, and –3. On days 1-5, mice were exposed to intermittent sleep disruption, whereby sleep was disrupted for 20 hours per day. Immediately following sleep disruption, mice were exposed to 1-hour social defeat stress or novel cage (control) conditions. Object location memory (OLM) testing was conducted 24 hours after social defeat, and tissues were collected six days later to measure inflammatory markers. Sleep was recorded using electroencephalography (EEG) and electromyography (EMG) throughout the experiment. Results In vehicle-treated mice, only the combination of sleep disruption followed by social defeat (double hit): 1) increased brief arousals and NREM beta (15-30Hz) EEG power in sleep immediately post-social defeat compared to baseline; 2) induced an increase in the proportion of rapid-eye-movement (REM) sleep and number of state shifts for at least 5 days post-social defeat; and 3) induced hyperlocomotion and lack of habituation in the OLM task. Immunization with MV prevented most of these sleep and behavioral changes. Conclusions Immunization with MV ameliorates a stress-induced sleep and behavioral phenotype that shares features with human posttraumatic stress disorder.

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209 Nightmare Content During the COVID-19 Pandemic: Influence of COVID-Related Stress and Sleep Disruption

SLEEP ◽

10.1093/sleep/zsab072.208 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A84-A84

Author(s):

Kathryn Kennedy ◽

Célyne Bastien ◽

Perrine Ruby ◽

William Killgore ◽

Chloe Wills ◽

...

Keyword(s):

Emotional Regulation ◽

Acute Stress ◽

Domestic Abuse ◽

Sleep Disruption ◽

Regulation Mechanism ◽

Regression Analyses ◽

Future Studies ◽

Race Ethnicity ◽

Related Stress ◽

Totalitarian Regimes

Abstract Introduction Nightmares are often associated with psychiatric disorders, though acute stress can also induce them. This study explores how the COVID-19 pandemic may have influenced the frequency and content of nightmares. Methods A sample of N=419 US adults completed online surveys about sleep and COVID-19 experiences. Participants were asked the degree to which they agree with statements including that due to the COVID-19 pandemic, they have greater general stress, worse overall sleep, and more middle-of-the-night insomnia. They were also asked if they experienced nightmares during the pandemic on a range of topics, including confinement, claustrophobia, suffocation, oppression, drowning, failure, helplessness, natural disasters, anxiety, evil forces, war, domestic abuse, separation from loved ones, totalitarian regimes, being chased, dangerous animals, sickness, death, COVID-19, and apocalypse. Logistic regression analyses examined each nightmare content as outcome and increased stress, worse sleep, and more middle-of-the-night insomnia as predictors, adjusted for age, sex, and race/ethnicity. Results Those who reported greater general COVID-related stress were more likely to have nightmares about confinement (OR=1.66,p<0.03), failure (OR=1.64,p<0.005), helplessness (OR=2.89, 0<0.0005), anxiety (OR=2.37,p<0.0005), war (OR=3.42,p<0.0005), separation (OR=2.23,p<0.0005), totalitarianism (OR=3.78,p<0.003), sickness (OR=1.92,p<0.003), death (OR=1.66,p<0.01), COVID (OR=1.96,p<0.01), and apocalypse (OR=2.92,p<0.0005). Those who reported worsened sleep were more likely to have nightmares about confinement (OR=1.80,p<0.003), oppression (OR=2.99,p<0.0005), failure (OR=2.12,p<0.0005), helplessness (OR=1.67, 0<0.0005), disaster (OR=1.86,p<0.005), anxiety (OR=1.97,p<0.0005), evil forces (OR=1.56,p<0.02), war (OR=2.08,p<0.002), domestic abuse (OR=2.22,p<0.009), separation (OR=2.01,p<0.0005), totalitarianism (OR=3.39,p<0.0005), sickness (OR=1.74,p=0.003), death (OR=2.03,p<0.0005), COVID (OR=2.15,p<0.001), and apocalypse (OR=1.86,p<0.006). Those who reported worsened middle-of-the-night insomnia were more likely to have nightmares about confinement (OR=1.60,p<0.01), oppression (OR=1.97,p<0.002), failure (OR=2.00,p<0.0005), helplessness (OR=1.60,p<0.001), disaster (OR=1.52,p<0.04), anxiety (OR=2.27,p<0.0005), war (OR=2.10,p<0.001), domestic abuse (OR=1.74,p<0.04), separation (OR=1.86,p<0.0005), totalitarianism (OR=1.87,p<0.03), sickness (OR=1.80,p<0.001), death (OR=2.00,p<0.0005), COVID (OR=1.68,p<0.009), and apocalypse (OR=1.65,p<0.01). Conclusion The results suggest that increased stress may induce negatively-toned dreams related to that stress. Future studies will have to determine whether (and when) this symptom indicates an emotional regulation mechanism at play or the failure of such a mechanism. Support (if any):

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