bluuebunny/crossref_metadata_2025 huggingface dataset:
018 The Role of Inflammatory Markers in Sleep in Individuals Post-Myocardial Infarction
Authors: Hirsch Sophie , Gaultney Jane , Crane Patricia
Published: May 2021

Introduction

Despite positive secondary prevention strategies post myocardial infarction (MI), including statin use and lifestyle changes, 32% of the annual MIs are recurrent (MIR). As coronary heart disease is related to atherosclerosis, a chronic inflammatory process, and sleep is associated with cardiovascular disease and innate immunity, understanding the role of sleep and inflammation and MIR is important in developing interventions to improve sleep, reduce inflammation, and delay or prevent MIR. This study aimed to explore the role of sleep quality and inflammatory markers on MIRs.

Methods

We conducted a secondary analysis of cross-sectional data of individuals (N=156) having at least one or more MIs within the last 3 to 7 years. Using the hypothalamus-pituitary-adrenal axis model (Irwin, 2019), we tested sleep quality (Pittsburgh Sleep Quality Index [PSQI]) predicting MIR, using inflammatory markers (hs C-Reactor Protein [CRP], Interleukin-1ß [IL-1ß] and Tumor Necrosis Factor alpha [TNFα]) as the simultaneous indirect paths. Race, sex and body mass index (BMI) were also examined using moderated mediation.

Results

The sample ranged in age from 34 to 92 (M = 65.37, SD = 12.13), BMI averaged 31.11 (SD = 7.34), and was comprised of mostly male (57.1%) and White adults (67.9%). PSQI predicted only IL-1ß (ß= .02; p < .01). IL-1ß predicted MIR (ß = .80, p = .05). The direct effect of PSQI to MIR was not significant (p =.12), the indirect path via IL-1ß was. This relationship was not moderated by race, sex, nor BMI.

Conclusion

IL-1ß is an inflammatory marker elevated after acute MI which does not reflect our selected sample. Inflammation may be an important marker of risk for MIR in those with poor sleep quality. Future studies should examine other markers of inflammation and sleep in those with MIR.

Support (if any):
023 Sleep in a Brainless Animal - The Relationship Between Centralization and Sleep in the Upside-down Jellyfish
Authors: Abrams Michael
Published: May 2021

Introduction

Though sleep is pervasive in animals, its fundamental roles, and the processes involved in generating the behavior, remain poorly understood. A key outstanding question in sleep regulation is whether sleep is controlled strictly by a top-down mechanism via activity of specific central nervous system (CNS) neurons or is controlled partially by bottom-up signals from neural and non-neural tissue. Recently, we showed that the upside-down jellyfish Cassiopea sleeps, providing an opportunity to study sleep control, regulation, and function in an animal without a CNS.

Methods

Cassiopea have a decentralized nervous system (DNS) of radially spaced interconnected ganglia called rhopalia along their bell margin that control muscle contractions. The signal to contract is sent to muscle fibers local to the initiating ganglion, and the contraction propagates outwards as a point source wave. We have developed computer programs to detect the controlling ganglion, which allows us to non-invasively determine ganglia activity, and to understand how a simple network of ganglia controls behavior. We are also using immunofluorescence, in situ hybridization, qPCR, and RNAseq to characterize the effect of sleep deprivation (SD) on the jellyfish nervous system.

Results

We have discovered a temporally centralized form of behavioral control that changes between day and night, and during SD. A subset of ganglia share behavioral control—while some almost never initiate contractions, others are active both day and night, or are mostly day-active or night-active, and SD drastically changes ganglia usage. Regions that increase activity at night are less active the following day, perhaps evidence of homeostatic regulation. Using RNAseq we found that during SD, one nAChRα subunit increases expression ~3.8-fold and we are studying its role in arousal and sleep.

Conclusion

We are investigating a different kind of nervous system, one that is morphologically decentralized (a network of discrete ganglia), and yet temporally centralized (a subset of ganglia dominate activity control). Wake, sleep, and SD involve different ganglia activity patterns, different levels of centralization, and different gene expression. Thus, temporal centralization could provide a mechanism to explain how local sleep, via a bottom-up mechanism, can result in organismal sleep behavior.

Support (if any)

UC Berkeley Miller Postdoctoral Fellowship
024 Quiescent Wakefulness: Characterising the Impact of Oxytocin on Sleep-Wake Behaviour in Male and Female Rats
Authors: Raymond Joel , Everett Nicholas , Gururajan Anand , Bowen Michael
Published: May 2021

Introduction

Oxytocin is a versatile hypothalamic neuropeptide involved in diverse neurobehavioural processes. Since oxytocin can elicit anxiolytic and serenic effects, one could hypothesise that oxytocin should prime the brain for sleep and promote hypnogenesis. However, based on the social salience hypothesis—that oxytocin promotes prosocial behaviour and directs attention toward social stimuli—one could also posit that oxytocin should promote wakefulness. At present, little research has comprehensively characterised the effect of oxytocin on sleep-wake behaviour and no explanation to reconcile these two seemingly competing hypotheses has been proposed.

Methods

This study investigated the effects of oxytocin on sleep-wake outcomes using radiotelemetry-based polysomnography in adult male and female Wistar rats. Oxytocin was administered via the intraperitoneal (IP; 0.1, 0.3 and 1 mg/kg) and intranasal (IN; 0.06, 1, 3 mg/kg) routes. Caffeine (IP and IN; 10 mg/kg) was also administered as a wake-promoting positive control. Additionally, pre-treatment with the oxytocin receptor (OTR) antagonist L-368,899 (IP; 5 mg/kg) and vasopressin 1a receptor (V1aR) antagonist SR49059 (IP; 1 mg/kg) followed by oxytocin (IP; 1 mg/kg) was conducted to determine which receptor(s) mediated sleep-wake effects of oxytocin.

Results

In both male and female rats, IP oxytocin produced dose-dependent effects on sleep-wake behaviour. Specifically, oxytocin initially promoted quiescent wakefulness (a restful but conscious state) at the cost of reducing both active wakefulness and sleep. Throughout the 1.5-hour period post-administration, oxytocin delayed REM sleep onset and reduced the proportion of both NREM and REM sleep. Conversely, IN oxytocin did not significantly alter any sleep-wake parameters at any dose tested. Caffeine demonstrated wake-promoting effects under both the IP and IN routes of administration. The involvement of OTR and V1aR binding in oxytocin-induced effects on sleep-wake outcomes will be discussed.

Conclusion

These findings appear to reconcile the two competing hypotheses: in rats, IP oxytocin appears to promote a state of quiescent wakefulness—one of calm and rest, but also of conscious responsivity to environmental stimuli. IN oxytocin demonstrated little to no effect on sleep-wake behaviour, which is a crucial finding given the escalating use of IN oxytocin as a therapeutic for conditions with comorbid disordered sleep.

Support (if any)

None.
027 GABAergic Neurons in the Dorsal Raphe Nucleus Are under the Influence of GABAergic Inputs from the Nucleus Pontis Oralis
Authors: Zhang Jianhua , Xi Mingchu , Fung Simon , Tobin Charles , Sampogna Sharon , Chase Michael
Published: May 2021

Introduction

Our previous study has shown that there is a direct connection between GABAergic neurons in the nucleus pontis oralis (NPO) and neurons of the dorsal raphe nucleus (DR), providing a morphological basis for the hypothesis that GABAergic inhibitory processes in NPO play an important role in the generation and maintenance of wakefulness as well as active (REM) sleep through the interaction with neurons in the DR. However, the target of such a GABAergic projection from the NPO within the DR is unknown. In the present study, a double-fluorescent labeling technique was employed to examine the target of GABAergic inputs to the DR.

Methods

Adult cats were deeply anesthetized and perfused transcardially. Subsequently, the brainstem containing the DR was removed, postfixed and cut into 15 μm coronal sections with a Reichert-Jung cryostat. The sections were immunostained with antibodies against GABA-A or GABA-B receptors and GABA following the procedure of double fluorescence immunohistochemistry.

Results

Under fluorescence microscopy, a large number of neurons were labeled with antibodies against either GABA-A receptor or GABA-B receptor. In addition, neurons labeled with antibody against GABA were observed in the DR. With double fluorescence immunohistochemical techniques, some neurons labeled by anti-GABA antibody were also stained with antibodies against GABA-A or GABA-B receptors.

Conclusion

The expression of GABA-A or GABA-B receptors by GABAergic neurons in the DR indicates that GABAergic neurons in the DR receive GABAergic inputs. Our previous study has demonstrated that these GABAergic inputs are from the NPO. These data provide a morphological foundation to support our hypothesis that, during wakefulness, NPO GABAergic “Executive” neurons suppress “Second-Order” GABAergic neurons in the DR, which, in turn, activate (disinhibit) serotonergic wake-on neurons in this nucleus.

Support (if any)

NS092383
031 The reduced benefit of sleep for memory trace consolidation with age
Authors: Toor Balmeet , van den Berg Nicholas , Ray Laura , Fang Lydia , Fogel Stuart
Published: May 2021

Introduction

Sleep is known to enhance the realization of novel solutions to problems. As we age, both the quantity and quality of sleep are reduced. Age-related deficits in sleep-dependent memory consolidation have been recently identified, however, the scope of these deficits is not. Here, we sought to investigate the behavioural and neuronal functional consequences of age-related changes in sleep for gaining insight into novel cognitive strategies (e.g., on the Tower of Hanoi; ToH).

Methods

40 healthy young adults (20–25 years), and 30 healthy older adults (60–85 years) participated, and were assigned to either the nap [young-nap (YN), older-nap (ON)] or wake [young-no-nap (YNN), older-no-nap (ONN)] conditions. Participants were trained on the ToH in the AM, followed by either a 90 minute nap opportunity or a period of wake, and were retested afterward. The ToH is a procedural task that requires the acquisition of a novel cognitive strategy (i.e., recursive logic). Alternating blocks of ToH practice and rest were performed while functional MRI scans were obtained at 3T to examine differences (pFDR<0.05) in brain activation from training to retest in young vs. older groups as a function of sleep [(YN-YNN)-(ON-ONN)].

Results

Sleep significantly benefitted the young but not the older participants (speed and accuracy) on the ToH. A bilateral difference in activation of the hippocampus was observed from training to retest between young and older subjects. Specifically, YN displayed decreased activation, whereas YNN showed increased activation. The older groups showed the opposite pattern whereby ON displayed increased activation whereas ONN showed decreased activation. The same pattern was observed for the middle temporal gyrus and medial prefrontal cortex. By contrast, the opposite pattern was observed in the premotor area, inferior and superior parietal cortex.

Conclusion

These results suggest that sleep differentially contributes to the realization of a novel cognitive strategy in young vs. older individuals, consistent with the notion that as the consolidation of a newly formed memory trace progresses, the hippocampus becomes less involved over time; especially so when sleep occurs during that time. Our results suggest that sleep preferentially contributes to this process in the young, but not in older individuals.

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032 Sleep Consolidates Memory for Strong but not Weak Information After Incidental Encoding
Authors: Wernette Elle , Fenn Kimberly
Published: May 2021

Introduction

Slow wave sleep (SWS) strengthens memory for studied information, but research on the effect of sleep on information that is not intentionally remembered is scarce. Previous research from our lab suggests sleep consolidates some information that has been encoded incidentally, meaning that it has been acted on but not intentionally remembered. It remains unclear what determines which information is consolidated during sleep after incidental encoding and what aspects of sleep are related to this mnemonic benefit. In two experiments, we test the hypothesis that sleep consolidates strong but not weak memory traces following incidental encoding and assess the relationship between memory performance and sleep attributes.

Methods

In Experiment 1, we manipulated memory strength within- and between-subjects. Participants rated words one or three times (within) in a shallow or deep incidental encoding task (between). In the shallow task, participants counted vowels in each word; in the deep task, participants rated each word on a scale from ‘concrete’ to ‘abstract’. Following a 12-hour period containing sleep or wakefulness, participants took a surprise memory test. In Experiment 2, participants rated words one or three times in the deep encoding task, received an 8-hour sleep opportunity with partial PSG, and took the surprise memory test.

Results

In Experiment 1, participants remembered words better after sleep than wake regardless of number of encoding trials, but only after deep encoding. There was not an effect of sleep following shallow encoding. In Experiment 2, SWS correlated negatively with response latency for correctly recognized words encoded once, but not those encoded three times. That is, participants who received more SWS showed faster performance.

Conclusion

Results suggest sleep consolidated information based on the depth of encoding, and this benefit was related to SWS. This work is broadly consistent with theories of memory consolidation that predict sleep is more beneficial for strong than weak memory traces, such as the synaptic downscaling hypothesis.

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036 The Effect of Exercise on Sleep Architecture and Memory Consolidation during a Daytime Nap
Authors: Collins Megan , Wamsley Erin , Napier Hailey , Ray Madeline
Published: May 2021

Introduction

Slow wave sleep (SWS) is thought to especially benefit declarative memory (i.e., memory for facts and events). As such, recent studies have used various methods to experimentally increase the amount of slow wave sleep that participants obtain, with the goal of assessing how SWS affects declarative memory consolidation. Studies dating back decades have reported that exercising before sleep may increase time spent in SWS. Thus, the aim of the current project was to determine whether exercising after learning verbal information enhances slow wave sleep during a subsequent nap and/or enhances memory for verbal information.

Methods

Participants who exercised regularly were recruited to attend two 2.5hr laboratory sessions. During each session, they trained on a paired associates learning task and then completed either a 20min cardiovascular exercise routine or a 20min stretching routine. Following a 1hr nap opportunity, participants were tested on their memory. PSG was recorded during the nap, and scored following AASM criteria. Participants were excluded from analysis if they failed to sleep for at least 10 min. Following exclusions, n=30 participants were included in analysis.

Results

Contrary to our hypotheses, there was no significant difference between the exercise and stretching conditions for minutes spent in slow wave sleep (p=.16), % time spent in slow wave sleep (p=.22), or raw improvement in paired associated performance (p=.23). The amount of SWS obtained during the nap did not correlate with performance in either condition (SWS min vs. memory in exercise condition: r28=.10, p=.60; sleep condition: r28=-.06, p=.74). Exercise did not affect time spent in any other sleep stage, nor did it affect total sleep time.

Conclusion

Contrary to our hypotheses and the results of prior research, we were unable to detect a significant effect of exercise on slow wave sleep. Also contrary to our hypotheses, exercise did not affect memory retention across the nap interval. These null results could indicate that there is no effect of exercise on nap sleep and/or associated memory retention. However, it could also be that we lacked sufficient power to detect effects that were smaller than expected.

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040 Sleep Deprivation Disrupts Binding of Information with Its Context
Authors: Kurinec Courtney , Whitney Paul , Hinson John , Hansen Devon , Van Dongen Hans
Published: May 2021

Introduction

Effective memory often requires recall of both specific information and the context in which the information was encountered. Total sleep deprivation (TSD) is known to impair memory for information items (e.g., words on a studied list), but the impact of TSD on binding, or associative linking, between items and context is not clear.

Methods

N=68 healthy adults (ages 22–40; 35 females) completed a 4-day (3-night) in-laboratory study. After a baseline night with 10h nighttime sleep opportunity, participants were randomly assigned to either 38h TSD (n=38) or a well-rested control (WRC) condition with 10h nighttime sleep opportunity (n=30). Both study arms concluded with a 10h nighttime recovery sleep opportunity. Participants completed a standardized recognition memory task at 14:50 on day 2 (baseline, session 1) and again 24h later (session 2). The memory task consisted of a study phase in which words with negative, positive, and neutral affective valence were spoken by a female or male speaker (50% each); followed immediately by a test phase, in which subjects made recognition judgments for the items (words) and their source (speaker).

Results

Mixed-effects ANOVA revealed significant interactions of session by condition for both word and speaker recognition (p<0.001). When sleep-deprived, TSD participants recognized fewer words and, for words that were correctly recognized, they were worse at recognizing the speaker, compared to baseline and to the WRC group. Negatively valenced words were associated with poorer word recognition (p<0.001), and in session 1 poorer source recognition (p = 0.032), but these valence effects did not interact with sleep deprivation.

Conclusion

TSD impaired memory for items, but more importantly, also impaired memory for the context in which items were presented, even if the items were themselves correctly recognized, and regardless of their affective valence. These results indicate that TSD may disrupt binding of information to its context, which could explain TSD deficits in decision-making tasks that require novel associative linking. Furthermore, our findings are important in real-world situations such as eyewitness accounts and perseveration of the influence of misinformation.

Support (if any)

NIH grant R21 CA167691 and CDMRP award W81XWH-20-1-0442
044 Slow oscillatory transcranial direct current stimulation enhances cognitive performance during subsequent sleep deprivation
Authors: Hughes John , Doty Tracy Jill , Ratcliffe Ruthie , Balkin Thomas
Published: May 2021

Introduction

The EEG slow oscillation of < 1 Hertz frequency has been implicated in various sleep functions, sparking a recent interest in slow oscillation enhancement strategies. In a seminal study, Marshall et al. (2006) demonstrated that 25 minutes of a slow oscillatory form of transcranial direct current stimulation (SO-tDCS) during early nocturnal sleep improved subsequent retention of word pairs learned prior to sleep, consistent with a proposed role for the slow oscillation in sleep-related memory consolidation. Another proposed function of the slow oscillation is synaptic downscaling, hypothesized to constitute the physiological basis for satisfying the homeostatic drive for sleep, per the synaptic homeostasis hypothesis of Tononi and Cirelli. We sought to determine if SO-tDCS could enhance the restorative properties of sleep, by enhancing slow oscillation activity, during a restricted sleep opportunity by assessing performance during a subsequent period of sleep deprivation (SD).

Methods

Twenty-six healthy volunteers were randomized into two groups. Participants either received electrical stimulation with 50 minutes of SO-tDCS at 0.75Hz, or sham stimulation, during the second hour of a restricted two hour sleep opportunity (11:00PM TO 1:00AM), followed by a 46 hour period of SD and then two recovery nights of sleep. Vigilance was assessed periodically with the Psychomotor Vigilance Test (PVT) during a baseline day, SD, and during the two days following recovery sleep nights.

Results

A mixed linear regression revealed significant main effects of day, group, and the interaction between group and day on mean reaction time (RT). Posthoc analysis revealed faster RTs following stimulation on day 2 of SD. It was also found that participants in the stimulation group had fewer major lapses (RTs > 500 ms) than those in the sham group over the first three days following stimulation.

Conclusion

Slow oscillatory transcranial direct current stimulation during a portion of a restricted period of sleep appears to enhance sleep’s restorative properties and improves cognitive performance during subsequent sustained wakefulness. The mechanistic basis for this phenomenon may be increased slow oscillation induced synaptic renormalization.

Support (if any)

Department of Defense Military Operational Medicine Research Program (MOMRP)
046 Sleep-dependent prospective memory consolidation is impaired with aging
Authors: Leong Ruth , Lo June , Chee Michael
Published: May 2021

Introduction

Existing literature suggests that sleep-dependent memory consolidation is impaired in older adults but may be preserved for personally relevant information. Prospective memory (PM) involves remembering to execute future intentions in a timely manner and has behavioural importance. As previous work suggests that N3 sleep is important for PM in young adults, we investigated if the role of N3 sleep in PM consolidation would be maintained in older adults.

Methods

49 young adults (mean age±SD: 21.8±1.61 years) and 49 healthy older adults (mean age±SD: 65.7±6.30 years) were randomized into sleep and wake groups. After a semantic categorization task, participants encoded intentions comprising 4 related and 4 unrelated cue-action pairs. They were instructed to remember to perform these actions in response to cue words presented during a second semantic categorization task 12h later that encompassed either daytime wake (09:00-21:00) or overnight sleep with polysomnography (21:00-09:00).

Results

The significant condition x age group x relatedness interaction suggested that the sleep benefit on PM intentions varied according to age group and relatedness (p=0.01). For related intentions, sleep relative to wake benefitted young adults’ performance (p<0.001) but not older adults (p=0.30). For unrelated intentions, sleep did not improve PM for either age group. While post-encoding N3 was significantly associated with related intentions’ execution in young adults (r=0.43, p=0.02), this relationship was not found for older adults (r=-0.07, p=0.763).

Conclusion

The age-related impairment of sleep-dependent memory consolidation extends to prospective memory. Our findings add to an existing body of work suggesting that the link between sleep and memory is functionally weakened in older adulthood.

Support (if any)

This work was supported by the National Medical Research Council, Singapore (NMRC/STaR/015/2013) and the National Research Foundation, Singapore (NRF2016_SOL002).
064 Higher Resting HRV Enhances Protective Effects of Self-Reported Resilience Against the Impact of Poor Sleep Quality on PTSS
Authors: Huskey Alisa , Taylor Daniel , Friedman Bruce
Published: May 2021

Introduction

Poor sleep quality is a well-established risk for posttraumatic symptoms (PTSS; Casement et al., 2012; Germain et al., 2004; 2005). Conversely, self-reported resilience is a well-established protective factor against PTSS (Mealer et al., 2012; Wrenn et al., 2011) and has also been shown to moderate the negative impacts of stressful life events on sleep quality (Li et al., 2019). Fewer studies have investigated whether autonomic indices of regulatory control moderate the impacts of resilience and sleep quality on PTSS. Resting heart rate variability (HRV) is a widely supported measure of top-down regulation of cognitive, behavioral and autonomic outcomes (Thayer & Ruiz-Padial, 2006). Higher HRV has been linked with increased capacity for stress coping as well as regulation of affect and attention (Bornstein & Suess, 2000). This study investigates whether resting HRV moderates the relationship between resilience, sleep quality, and PTSS.

Methods

Participants completed the PTSD Checklist for DSM-5 criteria (PCL-5), the Pittsburg Sleep Quality Index (PSQI), and the Connor-Davidson Resilience Scale (CD-RISC-10). A resting baseline assessment of electrocardiogram was used to derive resting-state HRV. Participants (N = 42; 86% women; 76% Caucasian) were recruited from college courses and the surrounding community.

Results

Individuals were grouped into higher and lower HRV. In the lower HRV group, resilience was not related to PTSS, but poorer sleep quality predicted higher PTSS severity (B=.79). Specific components of sleep quality that predicted PTSS in the lower HRV group were sleep disturbance (B=.38) and daytime dysfunction (B=.76). In the higher HRV group, greater resilience predicted lower PTSS severity (B=-.63), but sleep quality was not related to PTSS. Sleeping medication was the only component that predicted PTSS in the higher HRV group, such that less sleep medication was related to higher PTSS (B=-.751).

Conclusion

These findings suggest that higher HRV in combination with a self-perception of greater resilience are protective factors against PTSS as well as the effects of poorer sleep quality on PTSS. Resting HRV provides an index of regulatory control that may also be a physiological component of resilience.

Support (if any)

This project was funded by the Dean’s Discovery Fund at Virginia Tech.
082 The Association Between Excessive Daytime Sleepiness and Math Performance in Adolescents
Authors: Scholes Samantha , Rao Akhila , Somerville Gail , Boursier Johanne , Gruber Reut
Published: May 2021

Introduction

Excessive daytime sleepiness (EDS) is defined as an increased tendency to fall asleep in a setting where an individual would be expected to stay awake and alert. Previous studies have found that EDS is associated with poor academic performance but fell short of examining the associations between EDS and achievement in specific academic subjects. Academic performance in mathematics is the most prominent predictor of later success. Findings from studies examining the associations of academic achievement in math and EDS have been inconsistent as some studies have found results indicating the EDS negatively impacts math while others found no such relationship. The aim of this study was to investigate the association between EDS and performance in mathematics in high school students. It was hypothesized that higher level of reported EDS would be associated with lower grades in mathematics.

Methods

116 typically developing adolescents (38 male) between 12–17 years of age (M=13.87, SD=1.38) participated. EDS was measured by the Sleep Disorder Inventory for Students (SDIS); Academic achievement in mathematics was measured by child’s report cards; Sleep was assessed for seven nights using actigraphy and sleep logs.

Results

A hierarchical multiple regression analysis was conducted to examine the associations between parent-reported EDS (independent variable) and their child’s academic achievement in mathematics (dependent variable) while controlling for sleep variables (bedtime, waketime, and duration) and sex. Higher levels of EDS was negatively associated with lower grades in mathematics [F(5,109)= 3.60, p<.01; β= -0.21, p= 0.03].

Conclusion

EDS was signiﬁcantly associated with report card grades in mathematics in typically developing adolescents. Given the cross-sectional design of the study, it can not identify what led to EDS in this sample of typically developing adolescents. We propose that future studies examine potential causes for adolescents’ EDS, including factors that could impair sleep quality (e.g., undiagnosed sleep disorders) or restrict sleep duration (e.g., life-style choices such as the use of electronic devices at night). This is important as it could help to identify targets for intervention aiming at decreasing EDS and ultimately improving academic performance in mathematics.

Support (if any):
089 Impact of A Single Sleep Education Session on Beliefs and Attitudes Among People with Excessive Daytime Sleepiness: A Pilot Study
Authors: Wills Chloe , Tubbs Andrew , Grandner Michael
Published: May 2021

Introduction

Excessive daytime sleepiness is associated with adverse health outcomes and substantial functional deficits. However, little is known about experiences among these individuals and whether some education about sleep health would be helpful.

Methods

N=28 participants with excessive daytime sleepiness (ESS>=10) but no other major medical problems were recruited from the community. The intervention was a single 2-hour sleep education workshop. Participants were randomized to either the education session or a wait-list control. Change from baseline on Epworth Sleepiness Scale (ESS), Dysfunctional Beliefs About Sleep (DBAS) scale, Fatigue Severity Scale (FSS), Insomnia Severity Index (ISI),pHQ9 depression scale, and GAD7 anxiety scale were evaluated versus controls, adjusted for age, sex, and race/ethnicity. Also,participants were asked whether they agree to a range of beliefs/attitudes about sleep before and after the session (as part of intervention or following wait list). Posttest-Pretest difference scores were compared to determine if any were changed by the session (nominal significance p<0.05).

Results

Compared to the wait-list control, those who received the education session did not show differences in sleepiness (4.2% reduction,p=0.73) or dysfunctional beliefs about sleep (52.1% reduction,p=0.07), but they did demonstrate a 26.5% reduction in fatigue (p=0.01), a 55.2% reduction in insomnia severity (p=0.004), a 59.1% reduction in depression score (p=0.02), and a 54.5% reduction in anxiety score (p=0.04). The single session resulted in increased agreement with the statements, “People with daytime sleepiness should discuss their problems with their doctor or health care provider” (t=-2.3,p=0.03), “I understand the basics of how sleep works” (t=-2.2,p=0.04), “I understand the basics of how sleepiness works” (t=-2.7,p=0.01), “Excessive daytime sleepiness is something that can be improved with psychological treatment” (t=-2.3,p=0.03), and “I know what to do if…” “I have trouble falling asleep” (t=-4.3,p=0.0003), “I have trouble with poor quality sleep” (t=-5.1,p=0.0001), and “I experience daytime sleepiness” (t=-3.0,p=0.007).

Conclusion

A brief sleep health education session improved sleep and mental health in individuals with daytime sleepiness, even if it did not improve sleepiness. Further, the session did likely provide useful educational information.

Support (if any)

This work was supported by Jazz Pharmaceuticals
099 A randomized factorial study to understand the components of behavioral sleep extension
Authors: Baron Kelly , Trela-Hoskins Sarah , Allen Chelsea , Duffecy Jennifer , Lincoln Layla
Published: May 2021

Introduction

Recent studies have demonstrated that behavioral sleep extension can increase sleep duration among short sleepers. However, little is known about the contribution of the intervention components. The goal of this study is to examine the effects of a fitbit and coaching on sleep extension in a behavioral sleep extension intervention.

Methods

Participants included adults aged 25 to 65 years with sleep duration <7 hours who were randomized into one of four groups: self-management, Fitbit, coaching, or Fitbit + coaching. The self-management group did not receive any intervention materials. The other three groups received sleep educational materials emailed weekly. The coaching intervention (5-min telephone call) was delivered weekly for 6 weeks to the coaching and Fitbit+coaching groups to enhance motivation. Assessments were completed at baseline, post intervention (6 weeks), and 12-week follow- up. Participants completed self-report questionnaires and actigraphy at study visits. Results were analyzed using mixed models.

Results

Enrollment and data collection were ended prematurely due to the COVID-19 pandemic. Participants included 32 adults (self-management n=8, coaching n=11, Fitbit n=11, and Fitbit+coaching n=8). Fitbit+coaching group increased hours of sleep by 0.62 h hours more (95% CI: 0.04, 1.20; p=0.047) than the self-management group between their first and second visit. Coaching and the Fitbit groups showed estimated improvements over the self-management group as well: 0.54 h and 0.39 h, respectively, though their differences were not found to be statistically significant (p=0.081 and p=0.20, respectively). At the 12-week follow-up visit, there were no statistically significant differences between groups but the Fitbit+coaching group did maintain their sleep improvement.

Conclusion

These results suggest that sleep extension intervention components may affect the pattern of sleep changes, but more research is needed to refine and explore changes in sleep with behavioral interventions.

Support (if any)

R01NR018891
104 The influence of self-reported distractions on the Psychomotor Vigilance Task (PVT) in laboratory and field environments
Authors: Bathurst Nicholas , Gregory Kevin , Arsintescu Lucia , Costedoat Gregory , Evans Erin
Published: May 2021

Introduction

The Psychomotor Vigilance Task (PVT) is a measure of vigilant attention that is commonly used in laboratory environments to assess the neurobehavioral impact of sleep loss and circadian misalignment. The PVT has been increasing in popularity for use in field environments; however, the potential for distraction is higher in the field compared to the lab. It is unclear how distractions experienced by individuals taking the PVT in the real world may influence reaction time metrics. We investigated the influence of self-reported distraction on PVT outcomes across laboratory and field environments.

Methods

We examined PVT data from five studies including short (n=36 participants, 3799 PVTs) and long-haul (n=75 participants, 3282 PVTs) airline personnel, control center personnel (n=5 participants, 96 PVTs), and healthy individuals who participated in a study involving at-home and laboratory assessments (n=12 participants, 486 and 310 PVTs). Individuals in all of the studies were asked to complete the five-minute NASA PVT at least three times daily. Participants were asked to indicate the number of distractions they experienced immediately after each PVT. Mean PVT reaction time (RT) and number of distractions were computed for each study and overall.

Results

Participants reported more distractions in field environments compared to the lab (short-haul=1.29 +/- 1.48, long-haul=0.66 +/- 1.07, control-center=1.20 +/- 1.37, at-home=0.86 +/- 1.36, laboratory=0.46 +/- 1.07) Across all studies, we found that PVT RT slowed as self-reported distractions increased (all studies combined: 0 distractions=PVT RT 275.7ms; 1=285.0ms; 2=304.0ms; 3=322.9ms; >4=408.6ms). These findings were similar for healthy participants completing PVTs at home (0 distractions=286.4ms; 1=309.9ms; 2=328.3ms; 3=369.8ms; >4=385.1ms) but were less consistent during in-lab assessments (0 distractions=278.7ms; 1=316.2ms; 2=396.2ms; 3=370.4ms; >4=354.4ms). These findings were similar for other PVT outcomes.

Conclusion

Participants reported more distractions in field environments compared to the laboratory. Our findings suggest that the number of distractions that individuals report experiencing while taking a PVT increases the reaction time registered by the device. Researchers should collect information about distractions during the PVT and should be aware that distractions may influence the recorded PVT reaction time.

Support (if any)

NASA Airspace Operations and Safety Program, System-Wide Safety Project
105 Sleep Behaviors Are Differentially Associated with Eating Behavior Characteristics Based on Sex
Authors: Barragan Rocio , Zuraikat Faris , Tam Victoria , Scaccia Samantha , Cochran Justin , Li Si , Cheng Bin , St-Onge Marie-Pierre
Published: May 2021

Introduction

Poor sleep health is a key determinant of obesity risk, largely explained by overconsumption of energy. Eating behavior characteristics are predictive of energy intake and weight change and may link sleep with risk factors for obesity. However, the relationships between sleep and dimensions of eating behavior, and potential individual differences in these relations, are not well characterized. Elucidating these relations may aid in the development of targeted strategies to mitigate obesity risk. Therefore, we aimed to 1) evaluate whether associations of sleep were related with eating behavior characteristics, 2) explore if these associations differed by sex.

Methods

This was a cross-sectional analysis of 179 adults aged 20–73 y (68.7% women; 64.8% with BMI≥25 kg/m2; 27.4% minority). Sleep was assessed over 2 wk using wrist actigraphy; eating behavior characteristics (dietary restraint, disinhibition and hunger) were measured with the Three-Factor Eating Questionnaire. Linear regression models were used to evaluate associations of sleep with eating behavior characteristics, adjusting for confounding variables. In separate models, sex was added as an interaction term and analyses were stratified when interactions were significant (p<0.10).

Results

Variable (sleep midpoint standard deviation >60 min) vs. stable sleep timing was associated with greater tendency towards hunger (β=0.84 ± 0.39, p=0.03). When evaluated on the continuous scale, lower sleep efficiency (β=-0.13 ± 0.05; p=0.01), longer wake after sleep onset (β=0.03 ± 0.01; p=0.01) and higher sleep fragmentation index (β=0.074 ± 0.036; p=0.041) were associated with higher dietary restraint. Sex influenced associations of sleep efficiency, sleep onset latency, and sleep fragmentation index with hunger. In men, but not women, lower sleep efficiency (β=-0.15 ± 0.05; p<0.01), longer sleep onset latency (β=0.17 ± 0.07; p=0.02) and higher sleep fragmentation index (β=0.11 ± 0.04; p<0.01) were associated with greater hunger.

Conclusion

Objective measures of sleep were associated with eating behaviors previously linked with obesity and its risk factors. Moreover, we provide evidence of sex-specific associations between poor sleep and tendency towards hunger. Our results suggest that, particularly in men, differences in eating behavior traits may underlie susceptibility to overeating in response to poor sleep.

Support (if any)

Supported by NIH grants R01HL128226 and R01HL142648 and AHA grant 16SFRN27950012 (PI: St-Onge).
106 Self-Reported Sleep and Resilience
Authors: Persich Michelle , Cloonan Sara , Grandner Michael , Killgore William
Published: May 2021

Introduction

Psychological resilience is the ability to withstand setbacks, adapt positively to challenges, and bounce back from the adversities of life. While the construct of resilience is broadly understood, the specific individual factors that contribute to the ability to be resilient and persevere in the face of difficulties remain poorly understood. We recently showed that psychological resilience during the COVID-19 pandemic was associated with a number of factors, including fewer complaints of insomnia, and others have suggested that sleep is an important contributor. We therefore tested the hypothesis that sleep quality and acute sleep quantity would combine to predict measures of psychological resilience and perseverance (i.e. “grit”).

Methods

We asked 447 adults (18–40 yrs; 72% female) to report the number of hours of sleep obtained the night before their assessment session (SLEEP), and complete several questionnaires, including the Pittsburgh Sleep Quality Index (PSQI), the Connor-Davidson Resilience Scale (CD-RISC), Bartone Dispositional Resilience Scale (Hardiness), and the Grit Scale. Sleep metrics were used to predict resilience, hardiness, and grit using multiple linear regression.

Results

For resilience, PSQI (β=-.201, p<.00003) and SLEEP (β=.155, p<.001) each contributed uniquely to prediction of CD-RISC (R2=.08, p<.00001). Hardiness was also predicted (R2=.08, p<.00001) by a combination of PSQI (β=-.218, p<.00001) and SLEEP (β=.128, p=.007). Interestingly, worse sleep quality over the past month on the PSQI (β=.13, p=.008) in combination with more SLEEP the night before the assessment (β=.137, p=.005) each contributed uniquely to higher Grit (i.e., perseverance; R2=.03, p=.003).

Conclusion

Self-reported sleep quality and quantity were both independently associated with greater self-reported resilience, hardiness, and grit. While better sleep quality and more sleep the night before testing each uniquely predicted greater resilience and hardiness, a different pattern emerged for Grit. The combination of lower quality sleep over the past month followed by greater recent sleep duration was associated with increased perseverance. Whereas sleep quality appears to be more important for general resilience/hardiness, recent sleep time appears more important for the subjective perception of perseverance. Because these data are purely self-report and cross sectional, future work will need to determine the longitudinal effects on behavior.

Support (if any):
107 Sleep Quality and Duration Are Associated with Greater Trait Emotional Intelligence
Authors: Persich Michelle , Cloonan Sara , Grandner Michael , Killgore William
Published: May 2021

Introduction

Lack of sleep has been associated with altered connectivity between the emotion-regulating regions of the medial prefrontal cortex and the emotionally reactive structure of the amygdala. This altered brain function following insufficient sleep is believed to impair a range of emotional perception and regulation capacities. Our prior research has also shown that two nights of total sleep deprivation led to significant declines in Trait Emotional Intelligence (TEI) and other aspects of emotional processing and perception. Nonetheless, the extent to which general sleep quality and acute sleep duration may contribute to everyday TEI outside of laboratory conditions remains unknown. We hypothesized that poorer sleep quality and the amount of sleep obtained the night before assessment would both predict TEI scores.

Methods

447 adults (18–40 yrs; 72% female) completed the Pittsburgh Sleep Quality Index (PSQI) and a question about the number of hours of sleep obtained the night before the assessment (SLEEP), as well as the Petrides Trait Emotional Intelligence Questionnaire (TEIQue). Sleep metrics were used to predict Total TEI, and the four TEIQue factors (Wellbeing, Self-Control, Emotionality, and Sociability) using multiple linear regression.

Results

Both PSQI (β=-.275, p<.00001) and SLEEP (β=.130, p<.00001) each contributed uniquely to prediction of Total TEI (R2=.11, p<.00001). Wellbeing was also predicted by a combination of PSQI (β=-.272, p<.00001) and SLEEP (β=.129, p=.006). In contrast, for Self-Control, only PSQI was significantly related (β=-.296, p<.00001). Both PSQI (β=-.131, p<.007) and SLEEP (β=.103, p<.034) each contributed to Emotionality. Finally, both PSQI (β=-.126, p<.010) and SLEEP (β=.107, p<.028) each contributed to Sociability.

Conclusion

Greater total TEI was uniquely predicted by a linear combination of 1) better general sleep quality over the past month and 2) greater quantity of sleep the night before the assessment session. The same pattern held for all scale factors, except Self-Control, which was only related to sleep quality over the past month. Although limited by the cross-sectional nature of the data, these findings support prior work suggesting that lack of sleep alters normal emotional processing and further suggests that both long-term sleep quality and acute restriction of sleep can affect trait-like emotional domains.

Support (if any):
109 Chemogenetic silencing of corticotropin releasing factor neurons in the paraventricular nucleus: the effect on post-stress sleep
Authors: Gvilia Irma , Kumar Sunil , McGinty Dennis , Szymusiak Ronald
Published: May 2021

Introduction

We have previously shown that pharmacological elevation of corticotropin releasing factor (CRF) signaling in the brain results in exacerbation of sleep disturbances evoked by the exposure of rats to an acute stressor, the dirty cage of a male rat. In the present study we (1) assessed wake-sleep behavior of mice after the exposure to the dirty cage stress paradigm, and (2) examined the effect of chemogenetic silencing of CRF neurons in the hypothalamic paraventricular nucleus (PVN) on sleep occurring following the exposure to this stressor.

Methods

First, a group of mice (n=12) was implanted with EEG/EMG electrodes. In two weeks, post-surgery, six mice were transferred to dirty cages of male rats and recorded for 24 hours. Control mice were transferred to clean cages. In the second study, a group of CRF-ires-cre mice (n=8) received bilateral injections of AAV-hSyn-DIO-hM4Di-mCherry targeting the PVN. The other group of CRF-ires-cre mice (n=8) was injected AAV-hSyn-DIO-mCherry (control vector). All mice were implanted with EEG/EMG electrodes. Dirty cage experiments were started following a 4-week postsurgical period to allow gene recombination and expression. Mice were subjected to intraperitoneal (IP) administration of clozapine-n-oxide (CNO; 3 mg/kg) at ZT1, placed into dirty cages, and recorded for post-stress sleep.

Results: Results

In mice expressing hM4Di inhibitory DREADDs (designer receptors activated by designer drugs) versus mice injected with control AAV, IP CNO (3 mg/kg) resulted in a significant decrease of post-stress sleep onset latency, decrease of time spent in wakefulness (first hour, 74±5.3 vs. 89±11.0, second hour, 37.2±10.3% vs. 81.3±9.3%; third hour, 40.1±3.3% vs. 47.1±14.3%; fourth hour, 44.4±6.0 vs. 55.5±9.9), and increase in non-rapid eye movement (NREM) sleep time (26.0±5.4% vs. 11.0±11.1%; 62.8%±9.8 vs. 18.7 ± 9.6%; 59.9±3.2% vs. 52.9±14.5%; 55.6±6.2 vs. 44.5±10.0). The hM4Di expressing mice exhibited longer episodes of NREM sleep, compared to mice injected with control AAV (first hour, 133.3±80.1sec vs. 21±1.7sec; second hour, 43256±83.4sec vs. 73.5±44.1sec; third hour, 459.2±139.8sec vs. 139±80.6sec; fourth hour, 233.1±82.6sec vs. 190±72.3sec).

Conclusion

Chemogenetic silencing of CRF neurons in the PVN attenuates acute stress-induced sleep disturbance in mice.

Support (if any)

Supported by Department of Veterans Affairs Merit Review Grant # BX00155605 and SRNSF (Georgia) grant FR-18-12533