
Allison BragerMorehouse School of Medicine | MSM · Department of Neurobiology
Allison Brager
PhD
About
78
Publications
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Introduction
I am a behavioral neurobiologist with an interest in sleep and chronobiology and their contributions to psychiatric, neurological, and inflammatory disease states. I have experience in both human and animal models of study. I have a popular neuroscience blog affiliated with the Society for Neuroscience annual meeting (www.dormivigilia.com) andiIn Fall 2014, a popular science book entitled Meathead: Unraveling the Athletic Brain, combining research in neuroscience with my pursuits as an athlete
Additional affiliations
September 2007 - August 2011
Education
September 2007 - July 2011
September 2003 - May 2007
Publications
Publications (78)
Dear Editor,
In an editorial to Nature (2005), the late Dr. J. Allan Hobson declared that “sleep is of the brain, by the brain, and for the brain [1].” Dr. Hobson—a pioneer in our field—was certainly not wrong. He spent a lifetime elucidating the neurocircuitry of REM sleep and consciousness. But recent evidence refines this central dogma. In 2017,...
Purpose of Review
This review discusses the opportunities and challenges of training and competing “around the clock.”
Recent Findings
This review focuses on three key areas of study to include: (1) diurnal variation in biologically-driven (circadian-dependent) energy utilization required for aerobic and anaerobic endurance; (2) chronotype and its...
Resilience, the ability to overcome stressful conditions, is found in most mammals and varies significantly among individuals. A lack of resilience can lead to the development of neuropsychiatric and sleep disorders, often within the same individual. Despite extensive research into the brain mechanisms causing maladaptive behavioral-responses to st...
Resilience, the ability to overcome stressful conditions, is found in most mammals and varies significantly among individuals. A lack of resilience can lead to the development of neuropsychiatric and sleep disorders, often within the same individual. Despite extensive research into the brain mechanisms causing maladaptive behavioral-responses to st...
Background:
The impact of sleep disorders on active duty Soldiers' medical readiness is clinically significant. Sleep disorders often present high comorbidity with disease states impacting readiness ranging from obesity and drug dependence. Patient data generated from military health databases can be accessed to examine such relationships. The cur...
The TNFα G308A gene polymorphism has been reported to influence performance impairment during total sleep deprivation (TSD). We investigated this effect in a randomized, double-blind, crossover laboratory study of repeated exposure to 48 h TSD with caffeine administration at different doses. In a retrospective analysis, we replicated the finding th...
Introduction
The impact of sleep disorders on active duty Soldiers’ medical readiness is clinically significant. Sleep disorders present high comorbidity with disease states directly impacting medical readiness, ranging from musculoskeletal injury (MSK-I), obesity, and drug dependence. The current study performed a risk assessment of sleep disorder...
Introduction
Sleep deprivation degrades the fidelity of human brain information processing, leading to cognitive impairment. Carriers of the A allele of a single nucleotide polymorphism of the TNFα gene (G308A, rs1800629) have been found to be resilient to cognitive impairment due to sleep deprivation as compared to individuals homozygous for the G...
Objective: We constructed research camps at single-effort ultramarathons (50 and 100 miles) in order to study human endurance capabilities under extreme sleep loss and stress. It takes > 24h, on average, to run 100 miles on minimal sleep, allowing us to construct 24h human performance profiles (HPP). Methods: We collected performance data plotted a...
Sleep disturbances, posttraumatic stress disorder, and traumatic brain injury are highly prevalent in military personnel and veterans. These disorders can negatively impact military performance. Although literature evaluating how posttraumatic stress disorder and traumatic brain injury directly impact military performance is limited, there is evide...
Poor sleep is a hazard of daily life that oftentimes cannot be avoided. Gender differences in daily sleep and wake patterns are widely reported; however, it remains unclear how biological sex, which is comprised of genetic and endocrine components, directly influences sleep regulatory processes. In the majority of model systems studied thus far, se...
Study objectives:
The purpose of the present study was to assess the extent to which sleep extension followed by sleep deprivation impacts performance on an attentional task with varying cognitive and attentional demands that influence decisions.
Methods:
Task performance was assessed at baseline, after one week of sleep extension, and after 40...
Objective:
Individuals vary in response to sleep loss: some individuals are "vulnerable" and demonstrate cognitive decrements following insufficient sleep, while others are "resistant" and maintain baseline cognitive capability. Physiological markers (e.g., genetic polymorphisms) have been identified that can predict relative vulnerability. Howeve...
Objective:
We constructed research camps at single-effort ultramarathons (50 and 100 miles) in order to study human endurance capabilities under extreme sleep loss and stress. It takes > 24h, on average, to run 100 miles on minimal sleep, allowing us to construct 24h human performance profiles (HPP).
Methods:
We collected performance data plotte...
Burke, TM, Lisman, PJ, Maguire, K, Skeiky, L, Choynowski, JJ, CapaldiII, VF, Wilder, JN, Brager, AJ, and Dobrosielski, DA. Examination of sleep and injury among college football athletes. J Strength Cond Res XX(X): 000-000, 2019-The purpose of this study was to characterize subjective sleep metrics in collegiate football players at the start of the...
During Antarctic isolation personnel are exposed to extreme photoperiods. A frequent observation is a sleep onset phase delay during winter. It is not known if, as a result, daytime sleeping in the form of naps increases. We sought to assess sleep patterns - with focus on daytime sleeping - and alertness in a Latin American crew overwintering in Ar...
The military lifestyle often includes continuous operations whether in training or deployed environments. These stressful environments present unique challenges for service members attempting to achieve consolidated, restorative sleep. The significant mental and physical derangements caused by degraded metabolic, cardiovascular, skeletomuscular, an...
Introduction
Disrupted sleep and sleep propensity are common sequelae of concussion in high-performing athletes. Although the summative effect of head injuries is widely accepted, the role of sleep quality and sleepiness in resilience and recovery is still poorly understood. This study quantified pre- and post-injury sleep quality and sleep propens...
Introduction
Here, we developed a metric known as a human performance response curve (hPRC) to demonstrate advantages and disadvantages during the field-of-play in a NFL regular season that relies on the principles of the human circadian timing system For each team and game of a NFL regular season, we plotted risk for concussion with respect to eac...
Introduction
Threat-related information is preferentially processed, facilitating quick and efficient response. However, the impact of sleep loss or extension on perception of and response to threatening information is not well known. While sleep loss has been found to increase amygdalar activity and negative mood, potentially facilitating threat p...
Introduction
Recently, we identified that a clock protein in skeletal muscle has the ability to alter recovery responses to sleep deprivation, presenting evidence for a muscle-brain axis of sleep regulation (Ehlen et al. 2017). Here, we continue a search for mechanism of action through a proteomic screen in C57BL/6J mice (same background as Ehlen e...
Objective/Background
It is widely established that insufficient sleep can lead to adverse health outcomes. Paradoxically, epidemiologic research suggests that individuals who report habitual nightly sleep greater than 9 h also are at risk for adverse health outcomes. Further, studies have shown that long sleepers have decreased activity levels, whi...
Introduction
Sleep loss is ubiquitous in military settings, and it can be deleterious to cognitive, physiological, and operational functioning. This is especially true in the military operational context (e.g., training, garrison, combat) where continuous operations prevent adequate time for rest and recuperation. Furthermore, even when servicememb...
Objective
To assess the effects of one week of sleep extension on mood, fatigue and subjective sleepiness in normal-sleeping young adults.
Methods
Twenty-seven adults (age 24.4±5.4 years, 11 female) participated. At-home baseline sleep/wake patterns were recorded with wrist actigraphy for 14 days. This was followed by two nights of in-lab baseline...
Introduction:
Insufficient sleep increases pain sensitivity in healthy individuals. Additionally, extending sleep (eg, increasing nocturnal sleep time or adding a mid-day nap) has been shown to restore pain sensitivity to baseline levels in sleep deprived/restricted individuals. Whether sleep extension can reduce pain sensitivity beyond baseline l...
Introduction
Previous studies have identified intra-individual variability in neurobehavioral performance under total sleep deprivation (TSD). It is hypothesized that intra-individual variability is under genetic regulation. Here, we examined intra-individual variation in targeted single-nucleotide polymorphisms (SNPs) associated with: a) resistanc...
Introduction
It is well established that west coast (WC) teams of the National Football League (NFL) win more night games, dating back to the 1970s. Recent data (Brager and Mistovich, 2017) show that this night game advantage for WC teams is due to fewer regular season injuries to linemen. Here, we extend upon these historical datasets to determine...
Introduction
Daytime sleepiness and nighttime sleep disturbance are commonly reported in mild traumatic brain injury (mTBI) patients. This suggests a difference in the accumulation and dissipation of sleep pressure between concussed and non-concussed patients. It is unknown whether or not these symptoms persist beyond 3 months post-injury. We sough...
Introduction
Nitrergic neurons of the dorsal raphe nucleus (DRN) are involved in the regulation of stress and sleep. Stress duration is an important variable to consider when discussing the response to stress because duration has been shown to have different effects on behavioral processes such as sleep. Duration of acute stress also affects intens...
Introduction
Subjective cognitive complaints are common in the chronic stages (>3 months since injury) of mTBI, yet there is limited evidence of objective neurocognitive deficits in this population. Neuroimaging studies have demonstrated that although cognitive performance is similar between mTBI individuals and controls, mTBIs have broader utiliza...
Introduction
It is well established that sleep is a key determinant for performance optimization and injury prevention. Despite this knowledge, collegiate athletes have insufficient sleep relative to their physiological needs. Here, we aim to reduce homeostatic sleep debt and optimize rhythm stability of rise times/bed times in collegiate athletes...
Introduction
There a few field studies that have examined human performance dynamics under total sleep deprivation. Here, the logistics of a single-effort ultra-marathon provided us with the opportunity to dissect the homeostatic loads and circadian properties of human endurance across a 100-mile race.
Methods
Race data was collected from 50-mile...
Sleep quality appears to be altered by traumatic brain injury (TBI). However, whether persistent post-injury changes in sleep architecture are present is unknown and relatively unexplored. We conducted a systematic review and meta-analysis to assess the extent to which chronic TBI (>6 months since injury) is characterized by changes to sleep archit...
Nitrergic neurons of the dorsal raphe nucleus (DRN) may play a role in physiological stress responses. The caudal lateral wings (CLW) are unique compared to other rostral-caudal DRN sub-regions because they contain distinct nitric oxide (NO) synthase (NOS) populations that are independent of tryptophan hydroxylase (TPH). NOS neurons in the CLW are...
Complete data for each sub-region at each duration.
This data table shows the raw data that was used to determine significance.
(XLSX)
Optical density graphs for individual animals.
These graphs show the percentage difference for each animal compared to the mean of control animals. The six-hour animals show the most consistent differences across sub-regions, especially in the caudal ventromedial (cv) sub-region.
(XLSX)
NC3Rs ARRIVE guidelines checklist.
(DOCX)
ELife digest
We spend nearly one third of our lives asleep. Sleep plays a critical role in human health and is regulated by multiple brain regions. Genes are some of the factors that control sleep. Recent studies have shown that mice in which a gene called Bmal1 had been completely removed, sleep more than mice that still have the gene. These Bmal1...
Brain and muscle-ARNT-like factor (Bmal1/BMAL1) is an essential transcriptional/translational factor of circadian clocks. Loss of function of Bmal1/BMAL1 is highly disruptive to physiological and behavioral processes. In light of these previous findings, we examined if transgenic overexpression of Bmal1/BMAL1 in skeletal muscle could alter metaboli...
West coast teams of the National Football League (NFL) are more statistically likely to win home night games against east coast opponents. The alignment of game times with daily rhythms of alertness is thought to contribute to this advantage. The present study aims to determine if rates of turnovers and injuries during the regular season, putative...
Study objectives:
Episodes of brief limb ischemia (remote preconditioning) in mice induces tolerance to modeled ischemic stroke (focal brain ischemia). Since stroke outcomes are in part dependent on sleep-wake history, we sought to determine if sleep is critical for the neuroprotective effect of limb ischemia.
Methods:
EEG/EMG recording electrod...
Unlabelled:
Individuals with Angelman syndrome (AS) suffer sleep disturbances that severely impair quality of life. Whether these disturbances arise from sleep or circadian clock dysfunction is currently unknown. Here, we explored the mechanistic basis for these sleep disorders in a mouse model of Angelman syndrome (Ube3a(m-/p+) mice). Genetic del...
Popular science book debunking the 'dumb jock' myth and focused on using neuroscience to enhance athletic performance and recovery
The underlying, biological genetic determinants that control ethanol drinking and gate sensitivity to elevated ethanol intake during environmental disruption remain largely unknown. To approach this question, we used a mutant mouse line that has a nonfunctional homolog of the clock gene PER2 and consequently, high avidity for ethanol, to characteri...
Electroencephalographic slow wave activity (SWA) during non-rapid eye movement (NREM) sleep results from the synchronous oscillation of cortical neurons and is the standard measurement of sleep homeostasis. SWA is not a direct measure of sleep pressure accumulation, but rather a measure of the NREM-sleep response to accumulated sleep pressure. Curr...
Shift work and trans-time zone travel lead to insufficient sleep and numerous pathologies. Here, we examined sleep/wake dynamics during chronic exposure to environmental circadian disruption (ECD), and if chronic partial sleep loss associated with ECD influences the induction of shift-related inflammatory disorder. Sleep and wakefulness were teleme...
Significant changes in NREM and REM sleep during the 12th week under environmental circadian disruption (ECD). Graph shows daily 24 h means±SEM of NREM, and REM sleep across the 12th week under ECD. [Insert] Table shows weekly 24 h means±SEM of NREM and REM sleep in shifted (ECD) versus control (non-shifted) animals. a shifted vs. control (one-way...
Differential misalignment of sleep/wake processes under environmental circadian disruption (ECD). [Left Panel] Peak 24 h times of wake, NREM, and REM sleep across each day of the 4th and 8th week under ECD. * vs. baseline (paired t-tests; p<0.05). [Right panel] Peak 24 h time of REM sleep plotted against peak 24 h time of NREM sleep across each day...
Cocaine is a potent disruptor of photic and non-photic pathways for circadian entrainment of the master circadian clock of the suprachiasmatic nucleus (SCN). These actions of cocaine likely involve its modulation of molecular (clock gene) components for SCN clock timekeeping. At present, however, the physiological basis of such an interaction is un...
Chronic sleep deficiency, defined as a state of inadequate or mistimed sleep, is a growing and underappreciated determinant of health status. Sleep deprivation contributes to a number of molecular, immune, and neural changes that play a role in disease development, independent of primary sleep disorders. These changes in biological processes in res...
Cocaine abuse is highly disruptive to circadian physiological and behavioral rhythms. The present study was undertaken to determine whether such effects are manifest through actions on critical photic and nonphotic regulatory pathways in the master circadian clock of the mouse suprachiasmatic nucleus (SCN). Impairment of SCN photic signaling by sys...
The PER2 clock gene modulates ethanol consumption, such that mutant mice not expressing functional mPer2 have altered circadian behavior that promotes higher ethanol intake and preference. Experiments were undertaken to characterize circadian-related behavioral effects of mPer2 deletion on ethanol intake and to explore how acamprosate (used to redu...
Acamprosate suppresses alcohol intake and craving in recovering alcoholics; however, the central sites of its action are unclear. To approach this question, brain regions responsive to acamprosate were mapped using acamprosate microimplants targeted to brain reward and circadian areas implicated in alcohol dependence. mPer2 mutant mice with nonfunc...
Alcohol dependence is associated with impaired circadian rhythms and sleep. Ethanol administration disrupts circadian clock phase-resetting, suggesting a mode for the disruptive effect of alcohol dependence on the circadian timing system. In this study, we extend previous work in C57BL/6J mice to: (i) characterize the suprachiasmatic nucleus (SCN)...
Alcohol abuse leads to marked disruptions of circadian rhythms, and these disturbances in themselves can increase the drive to drink. Circadian clock timing is regulated by light, as well as by nonphotic influences such as food, social interactions, and wheel running. We previously reported that alcohol markedly disrupts photic and nonphotic modes...
Chronic ethanol abuse is associated with disrupted circadian rhythms and sleep. Ethanol administration impairs circadian clock phase-resetting, suggesting a mode for the disruptive effect of alcohol abuse on circadian timing. Here, we extend previous studies to explore the effects of chronic forced ethanol on photic phase-resetting, photic entrainm...
Acute ethanol (EtOH) administration impairs circadian clock phase resetting, suggesting a mode for the disruptive effect of alcohol abuse on human circadian rhythms. Here, we extend this research by characterizing the chronobiological effects of chronic alcohol consumption. First, daily profiles of EtOH were measured in the suprachiasmatic nucleus...