The neuroscientist and codirector of 糖心传媒 Medicine<\/a>\u2019s Center for Translational Neuromedicine<\/a> had discovered what she and her husband and codirector Steven Goldman<\/a> would dub the glymphatic system<\/a>, a biological \u201cdishwasher\u201d that scrubs the brain of waste during sleep. It was a finding so important that Science<\/em> magazine would list it among its 10 breakthroughs of the year in 2013.<\/p>\n You wouldn\u2019t have guessed its importance if you\u2019d attended her prepublication talks at sleep conferences and meetings. She enthused to her colleagues about the idea of brain clearance, but they regarded her with open skepticism. \u201cThey were like, \u2018What is she talking about?\u2019\u201d Nedergaard recalls. \u201cPeople looked at me like I was crazy.\u201d<\/p>\n Yet the science was clear. Using sophisticated microscopy techniques to peer inside the brain, her work revealed a cellular cleaning cycle that flushes out toxic proteins primarily during sleep.<\/p>\n A decade and a half after those inauspicious meetings, Nedergaard\u2019s discovery has become an engine for research worldwide, generating nearly 2,000 scientific papers. About half of them, she notes with pride, are clinical papers that address the glymphatic system\u2019s role in diseases and conditions ranging from Alzheimer\u2019s and Parkinson\u2019s to strokes and migraines.<\/p>\n On this early March afternoon, Nedergaard, who last year became URochester\u2019s 11th fellow of the National Academy of Inventors<\/a>, is busy preparing for the Oxford Glymphatic & Brain Clearance Symposium<\/a>. The event, built on her foundational research, has attracted 250 registrants and a 50-person waiting list. Nedergaard is the keynote speaker.<\/p>\n Nedergaard\u2019s discovery is perhaps the most dramatic chapter in a story about sleep that has been building for a generation at URochester<\/a>. But it is far from the only one. In labs, clinics, classrooms, and beyond, the University has built a formidable concentration of expertise in sleep.<\/p>\n And it is a story that is growing ever more relevant at a moment when people have moved from bragging about how little sleep they need to giving sleep its proper due as one of the essential pillars of health.<\/p>\n Scientists had long wondered how the brain, which gobbles up about 20 percent of our body\u2019s energy, maintained itself. In the rest of the body, the lymphatic system works alongside the bloodstream to clear away waste. But the blood-brain barrier blocks that system entirely, leaving the brain without an obvious mechanism for cleaning itself.<\/p>\n One long-held theory was that the brain had its own version of a lymphatic system that used cerebrospinal fluid. But the methods scientists had typically used to understand the process\u2014studying brain sections of dead animals\u2014had left plenty of unanswered questions.<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" URochester\u2019s researchers and clinicians are helping us understand the science of sleep\u2014including how it might be one of the most consequential forces in human health.<\/p>\n","protected":false},"author":1432,"featured_media":702972,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[41112,42472],"tags":[21502,19162,29752,18632,8366,42942,42492,16072,18432],"class_list":["post-702952","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-from-the-magazine","category-health-medicine","tag-arthur-satz-department-of-music","tag-center-for-translational-neuromedicine","tag-douglas-kelley","tag-hajim-school-of-engineering-and-applied-sciences","tag-maiken-nedergaard","tag-matthew-baileyshea","tag-medical-center","tag-school-of-arts-and-sciences","tag-school-of-medicine-and-dentistry"],"acf":{"external":"","hide_featured_image":false,"related":"show_related","style":[702212,695892,703152],"content_modules":[{"acf_fc_layout":"media_text_new","anchor":"","class":"pt-0","overline":"","title":"![\"Stylized](\"https:\/\/www.rochester.edu\/newscenter\/wp-content\/uploads\/2026\/05\/review-spring-2026-sleep-science-glymphatic-system.jpg\")
The whys of zzzzs<\/h3>\n
To sleep, perchance to clean...<\/h3>","content":"From an evolutionary standpoint, sleep seems like a terrible idea. Every night, we willingly surrender consciousness, mobility, and vigilance\u2014leaving ourselves vulnerable to predators, accidents, and the elements. And yet sleep, which is essentially universal across the animal kingdom, is unavoidable.\r\n\r\nBut it turns out that sleep is not a passive state at all. Instead, it\u2019s a critical time when the brain performs one of its most important jobs: cleaning itself.","cta":"","bg":"#00205b","type":"embed","image":"","embed":"https:\/\/www.youtube.com\/watch?v=kgpgbHvnBFM","video":"","layout":"left","animation":"animation-false"},{"acf_fc_layout":"text","anchor":"","css_class":"pt-35","title":"","content":"Nedergaard\u2019s work used an advanced two-photon microscope to reveal the process in an entirely new way. \u201cWe could look into a [live] brain, and we could visualize, in real time, that this fluid was actually flowing in and flowing out,\u201d she says. What they saw was a pumping system: cerebrospinal fluid coursing through channels alongside blood vessels, collecting toxic waste and carrying it away.\r\n\r\nIt was essential foundational work. A follow-up paper<\/a> went further, showing how channels between neurons widen during sleep, allowing cerebrospinal fluid to flood in and flush out accumulated waste far faster than when we are awake. The findings hit like a thunderclap, recalls Wilfred Pigeon<\/a>, director of the University\u2019s Sleep and Neurophysiology Research Lab<\/a>. \u201cThe sleep world was like, \u2018Who is this person?\u2019\u201d he says. \u201cHer work\u2019s a game changer.\u201d\r\n
Quiet time<\/b><\/h3>\r\nAs spouses and academic colleagues, Maiken Nedergaard and Steven Goldman love to talk shop. But Nedergaard\u2019s respect for sleep\u2019s power has led her to institute some firm nighttime rules. The first: Conversations stop an hour before Nedergaard\u2019s bedtime so she can wind down. \u201cIt drives [him] crazy,\u201d she admits. \u201cBut I emphasize sleep a lot.\u201d\r\n\r\n<\/div>\r\nWhile Nedergaard, who operates a second lab at the University of Copenhagen<\/a>, has gone on to collaborate with researchers at Harvard and Penn to further scientists\u2019 understanding of these processes\u2014a cross-institutional approach that is common in such research\u2014she has also leaned on the expertise of her URochester colleagues.\r\n\r\nOne of them is Douglas Kelley<\/a>, a mechanical engineering professor and an expert in fluid dynamics. Kelley first remembers being wowed by Nedergaard\u2019s work when he read about it in the University\u2019s daily morning email more than a decade ago. A few years later, when Nedergaard was working on a grant proposal she hoped would help her understand these cerebrospinal fluid flows more clearly, she partnered with Kelley; John \u201cJack\u201d Thomas, professor emeritus of mechanical and aerospace sciences; and Jessica Shang<\/a>, associate professor of mechanical engineering.\r\n\r\nUp until then, the cerebrospinal fluid flows captured on video had been tracked painstakingly by hand, particle by particle. Kelley\u2019s expertise brought a new level of computational muscle to the work. \u201cWe could use code we\u2019d already written to track 10,000 particles [at a time],\u201d he says, offering a more detailed understanding of the flow<\/a>.\r\n\r\nThe work has since grown far beyond particle tracking. Kelley is now combining MRI data with fluid dynamics equations fed into machine learning models\u2014a method that can reconstruct pressures and flow velocities that no microscope can directly measure. Because MRI can be used on humans, the research is inching toward something remarkable: \u201cWe\u2019re one step closer to noninvasive clinical measurement of flow in the brain,\u201d Kelley says, \u201cwhich could be used to diagnose all kinds of diseases [including Alzheimer\u2019s] much earlier than is possible now.\u201d\r\n
Losing sleep<\/h3>\r\nThe spotlight Nedergaard\u2019s discovery trained on URochester didn\u2019t just put her own lab on the map; it also helped illuminate how much exceptional sleep research and clinical work was already underway across the University.\r\n\r\nOne standout is the Sleep and Neurophysiology Research Lab, where Pigeon and his colleagues have spent years studying the causes, effects, and treatments of the most common\u2014and most commonly misunderstood\u2014sleep disorder: insomnia.\r\n\r\n[caption id=\"attachment_703032\" align=\"alignleft\" width=\"1500\"]
![\"Stylized](\"https:\/\/www.rochester.edu\/newscenter\/wp-content\/uploads\/2026\/05\/review-spring-2026-sleep-science-clinical.jpg\")
THE DOCTOR WILL SEE YOU NOW:<\/strong> Sleep disorders show up across nearly every specialty\u2014making sleep, as one URochester neurologist puts it, \u201ca glue specialty.\u201d (Illustration by Bryce Wymer)[\/caption]\r\n\r\nMore than just a night or two of rough sleep, insomnia disorder is defined as three or more nights of disrupted sleep per week for three or more months. At any given time, about 10 percent of the population meets that threshold.\r\n\r\nThe problem isn\u2019t just that we feel crummy after a lengthy period of poor sleep. Pigeon\u2019s research<\/a> has found that it has cascading health effects. \u201c[We know] that if you don\u2019t treat insomnia, it won\u2019t resolve on its own. And in the meantime, it\u2019ll make anything else you have\u2014depression, chronic pain, and many other conditions\u2014worse and more difficult to manage.\u201d\r\n\r\nInsomnia is also a major culprit behind truly catastrophic outcomes. Research by Todd Bishop<\/a>, an assistant professor of psychiatry, has found that insomnia is associated with increased suicide risk. And it\u2019s true even at the smallest timescales<\/a>: \u201c[We\u2019ve found that] if you had a poor night of sleep the night prior, you\u2019re more likely to endorse suicidal thought the next day,\u201d he says.\r\n\r\nThe relationship between insomnia and other conditions is similarly counterintuitive. Most people assume depression drives poor sleep, but Bishop and Pigeon\u2019s research points the other way. \u201cInsomnia can arise as a result of depression,\u201d says Pigeon, \u201cbut it is more common for insomnia to cause<\/em> an episode of depression.\u201d\r\n\r\nAnd yet, for a condition this widespread and this consequential, the most common treatment is wildly off the mark.\r\n\r\nThe vast majority of people who seek help for sleep issues in the United States are prescribed sleep medication<\/a>. It\u2019s a troubling disconnect, in part because these medications rarely address underlying problems with sleep.\r\n\r\nURochester research, in line with clinical guidelines, has found that the most effective first-line treatment is a structured psychological intervention called cognitive behavioral therapy for insomnia, or CBT-I. The four- to eight-session intervention is effective up to 80\u00a0percent of the time.","background_color":"#ffffff","width":"width-medium"},{"acf_fc_layout":"image_gallery","anchor_id":"","css_classes":"","overline":"","title":"The night shift<\/h3>","content":"One patient, two technologists, 10 hours, and reams of recorded data\u2014what really happens during a night in the sleep lab.<\/strong>\r\nPhotography by J. Adam Fenster and AJ Pow","above_below":"above","background_color":"#252525","images":[703892,703852,703862,703872,703882,703842,703942,703902,703922,703912,703932],"caption":"no","credit":"no"},{"acf_fc_layout":"text","anchor":"","css_class":"","title":"","content":"Few know this as well as Leisha Cuddihy<\/a>, who, as director of the Behavioral Sleep Medicine Clinic<\/a>, spends close to 80 percent of her clinic time working with patients who need CBT-I. As one of just a few hundred experts in the nation who is board-certified in behavioral sleep medicine, she has a packed calendar and a yearlong waiting list.\r\n\r\nWhile culturally some still consider sleep deprivation a badge of honor, Cuddihy sees the flip side: \u201cSome people have struggled for so long, they don\u2019t even remember what it\u2019s like to feel rested,\u201d she says.\r\n\r\nFor many, getting relief through CBT-I can feel like putting down a heavy weight that they didn\u2019t even know they were carrying. \u201cAt least once a week, a patient will tell me, \u2018You\u2019re the first person who\u2019s understood what this is like, and who has given me something that was helpful,\u2019\u201d she says.\r\n
Dream team<\/h3>\r\nIf there is a common thread across URochester\u2019s sleep work in foundational science, clinical research, and patient care, it may be this: It both knits together, and benefits from, the institution\u2019s expertise across disciplines. \u201cSleep is a \u2018glue specialty,\u2019\u201d explains Jonathan Marcus, a neurologist and the division chief of URochester\u2019s sleep medicine program.\r\n\r\nAfter all, the symptoms and consequences of sleep disorders refuse to stay in a single lane. They show up in the cardiologist\u2019s office (somewhere between 50 and 80 percent of patients with resistant hypertension also have sleep apnea), in the psychiatrist\u2019s office, and in the neurologist\u2019s office. It\u2019s a personal issue, but it\u2019s also a public health issue.","background_color":"#ffffff","width":"width-medium"},{"acf_fc_layout":"card_grid_new","anchor":"","css_class":"pt-0","title":"","description":"","card_grid_cta":"","background_color":"#ffffff","width":"content-width","cards":[{"acf_fc_layout":"card","card_width":"half","card_overline":"","card_title":"
In case you forgot: Sleep is not a luxury.<\/h3>","card_text":"\u201cI have cared for patients whose untreated sleep apnea was contributing to atrial fibrillation, hypertension, cognitive decline, and profound daytime impairment. When you see someone\u2019s blood pressure improve or arrhythmias stabilize, or hear a patient say, \u2018I didn\u2019t realize how tired I was until I wasn\u2019t,\u2019 it underscores that sleep is not a luxury. It is infrastructure for the brain and cardiovascular system.\u201d \u2014Jonathan Marcus<\/strong>","card_image_icon":"none","card_image":"","card_icon":"","card_icon_color":"#252525","card_image_size":"","card_image_placement_full":"","card_image_placement":"","card_background_color":"#f4f4f4","card_hover_color":"#283faf","card_link":"","card_hover_arrow":""},{"acf_fc_layout":"card","card_width":"half","card_overline":"","card_title":"
Lesson 1: Go to bed on time, every time.<\/h3>","card_text":"\u201cAt the outset of cognitive behavioral therapy for insomnia (CBT-I), I harp on consistency of bedtimes and wake-up times. There are several components to CBT-I, but I find [a consistent routine] to be of great value. I tell my patients that if they hear nothing else I say during the session, they should try to go to bed at the same time each night and wake up at the same time each morning.\u201d\u00a0\u2014Todd Bishop<\/strong>","card_image_icon":"none","card_image":"","card_icon":"","card_icon_color":"#252525","card_image_size":"","card_image_placement_full":"","card_image_placement":"","card_background_color":"#f4f4f4","card_hover_color":"#f4f4f4","card_link":"","card_hover_arrow":""}]},{"acf_fc_layout":"text","anchor":"","css_class":"pt-0","title":"","content":"Because of sleep\u2019s sprawling tentacles, both science and patients benefit when researchers and clinicians can find each other and make progress together. It\u2019s an interdisciplinary fluency that URochester has long cultivated.\r\n\r\nFor example, experts from neurology, sleep medicine, and otolaryngology team up to support patients who have obstructive sleep apnea<\/a> but can\u2019t tolerate the standard treatment\u2014a CPAP machine that delivers continuous pressurized air.\r\n\r\nWhile patients who fit this profile have typically had limited options, URochester has become one of the world\u2019s leading centers for surgically implanting hypoglossal nerve stimulators<\/a>, devices that keep the airway open during sleep. It\u2019s a delicate procedure that requires experts to work in concert, and URochester has become world-class at the process. \u201cWe\u2019ve implanted these devices in over 400 patients,\u201d says Marcus.\r\n\r\nThat volume matters. Where a peer program might see a handful of patients a year for the procedure, URochester can see 50 or more\u2014a difference that translates into hard-won expertise in patient selection, device calibration, and troubleshooting. URochester has recently been recognized as a national center of excellence for this work.\r\n\r\nThe University\u2019s strength in bringing together researchers and clinicians across departments also allows it to think even bigger about the field\u2019s future. Marcus, for instance, points to increasing evidence that the data collected during a polysomnogram\u2014an overnight sleep study that records brain wave activity, heart rhythms, breathing patterns, and body movements\u2014might function not just as a diagnostic tool, but as a predictive one: a kind of physiological portrait that could flag risk for cardiovascular disease, dementia, and dozens of other conditions before they develop.\r\n\r\nIt\u2019s a vision of sleep medicine not as a niche specialty, but as a broader window into long-term health.\r\n
The wee hours<\/h3>\r\nAdults, of course, aren\u2019t the only ones who experience sleep challenges. Children face an array of sleep issues, including sleep apnea, nocturnal enuresis (bedwetting), and insomnia.\r\n\r\nThe consequences of these conditions can feel very different from those experienced by adults, says Heidi Connolly<\/a>, chief of pediatric sleep medicine. Sleep problems in children can show up as learning difficulties, behavioral problems, and emotional volatility. Bedwetting, meanwhile, might prevent a child from going to sleepovers, and can dramatically affect a family\u2019s overall well-being as parents spend their own sleepless nights calming their child and doing laundry.\r\n\r\nSuccessful treatment can feel transformative. \u201cWhen you can solve these things\u2014when it means a kid can go to summer camp and overnights? Families are ecstatic,\u201d she says.\r\n\r\n[caption id=\"attachment_703042\" align=\"aligncenter\" width=\"2000\"]
![\"Stylized](\"https:\/\/www.rochester.edu\/newscenter\/wp-content\/uploads\/2026\/05\/review-spring-2026-sleep-science-pediatric.jpg\")
SLEEPING LIKE A BABY:<\/strong> Counting sheep takes on new meaning at URochester\u2019s pediatric sleep lab, where 1,500 sleep studies a year help children\u2014and their families\u2014finally get some rest. (Illustration by Bryce Wymer)[\/caption]\r\n\r\nConnolly\u2014who began seeing pediatric patients in the adult sleep lab in 2000 and launched a dedicated pediatric sleep lab<\/a> in 2005\u2014has built a regional powerhouse in pediatric sleep.\r\n\r\nHer six-bed lab is open at least six nights a week, with 1,500 sleep studies and close to 8,000 patient visits annually. A team of psychologists, behavioral analysts, nurse practitioners, pediatric neurologists, and pediatric pulmonologists supports the work.\r\n\r\nIn her own research, Connolly focuses on sleep apnea in children with cleft palates and those with single ventricle congenital heart disease. She\u2019s also working on a project with hematology experts exploring the link between iron deficiency and a sleep condition known as periodic limb movement disorder.\r\n\u201cPeople say \u2018Sleep when the baby sleeps,\u2019 but that doesn\u2019t always work the way we hope. Newborns don\u2019t have fully formed circadian rhythms like we do. Newborns may sleep for 20 minutes at a time, but we don\u2019t. It can also make people feel guilty when they can\u2019t sleep. For the postpartum period specifically, it\u2019s better to go to bed early\u2014like 8:00 p.m.\u2014and get some \u2018pre-sleep.\u2019\u201d \u2014Jennifer Marsella<\/em><\/blockquote>\r\nThat kind of all-embracing approach shapes everything about how the lab operates. It\u2019s what brings in clinicians like Emily Cromwell<\/a>, an assistant professor with appointments spanning psychiatry, child and adolescent services, and pediatrics.\r\n\r\nAnd it\u2019s a philosophy Cromwell\u2019s young patients get to experience firsthand. \u201cWhen I\u2019m working with kids who have nightmares, I\u2019ll often have them do tracking and diaries,\u201d she says. \u201cAnd I can say to them, \u2018You\u2019re a scientist, too\u2014let\u2019s look at your data.\u2019 We can see how things are getting better and better over time.\u201d\r\n\r\nThe best solutions, in Cromwell\u2019s opinion, come from collaborative efforts. \u201cEverybody has their own lens,\u201d she says, \u201cand they all have something to bring to the table.\u201d\r\n
Wake-up calls<\/h3>\r\nThe expertise URochester has built is deep, but the gap between what sleep science knows and what most people can access remains enormous. That\u2019s why the University\u2019s experts carry that knowledge beyond their labs and exam rooms into classrooms, communities, and even the phones in our pockets.\r\n\r\nJennifer Marsella<\/a>, assistant professor of neurology and medicine, teaches a Neurobiology of Sleep<\/a> undergraduate course that is among a rare few nationwide\u2014Stanford\u2019s among them\u2014to examine sleep from the level of cellular functioning all the way up to its effects on society.\r\n\r\nThe course, which fills up in a matter of days and consistently has a waiting list, includes guest lectures from sleep researchers and projects to help students think about how to improve sleep at a community level. \u201cStudents say that it\u2019s helped them improve their sleep. They also talk about how they\u2019ve helped friends and family,\u201d she says. \u201cSome of them become interested in going into neurology or sleep medicine, which many of them didn\u2019t understand was an option before.\u201d","background_color":"#ffffff","width":"width-medium"},{"acf_fc_layout":"card_grid_new","anchor":"","css_class":"pt-0","title":"","description":"","card_grid_cta":"","background_color":"#ffffff","width":"full-width","cards":[{"acf_fc_layout":"card","card_width":"third","card_overline":"","card_title":"
Developmental sleep fact<\/h3>","card_text":"We don\u2019t fully consolidate adult sleep and circadian rhythms until roughly age 25. After that, the amount of sleep we need<\/em> remains relatively stable across adulthood, even into older age. What changes with aging is sleep continuity and depth, not the amount of time that is needed.","card_image_icon":"none","card_image":"","card_icon":"","card_icon_color":"#252525","card_image_size":"","card_image_placement_full":"","card_image_placement":"","card_background_color":"#f4f4f4","card_hover_color":"#f4f4f4","card_link":"","card_hover_arrow":""},{"acf_fc_layout":"card","card_width":"third","card_overline":"","card_title":"
Don\u2019t take two of these\u2026<\/h3>","card_text":"Zolpidem (sold under the brand name Ambien, among others) is the most frequently prescribed medication for insomnia. And while it can effectively induce sleep, it also suppresses the glymphatic system in mice<\/a>. This might hinder the brain\u2019s natural waste-clearing processes, setting the stage for neurological disorders\u2014findings that raise concerns about zolpidem\u2019s long-term use and highlight the need to preserve natural sleep architecture for optimal brain function.","card_image_icon":"none","card_image":"","card_icon":"","card_icon_color":"#252525","card_image_size":"","card_image_placement_full":"","card_image_placement":"","card_background_color":"#f4f4f4","card_hover_color":"#f4f4f4","card_link":"","card_hover_arrow":""},{"acf_fc_layout":"card","card_width":"third","card_overline":"","card_title":"
Sleep is a biological process, not a performance score.<\/h3>","card_text":"Orthosomnia<\/em> refers to an unhealthy preoccupation with achieving \u201cperfect\u201d sleep, often driven by consumer sleep-tracking devices and clickbait articles about sleep.","card_image_icon":"none","card_image":"","card_icon":"","card_icon_color":"#252525","card_image_size":"","card_image_placement_full":"","card_image_placement":"","card_background_color":"#f4f4f4","card_hover_color":"#f4f4f4","card_link":"","card_hover_arrow":""}]},{"acf_fc_layout":"text","anchor":"","css_class":"pt-0","title":"","content":"Beyond the classroom, Cuddihy is working to expand access to sleep support at a systems level. As the president-elect of the Society of Behavioral Sleep Medicine<\/a>, she is helping build the infrastructure to train and certify a new generation of CBT-I providers. The society recently announced an accreditation pathway for CBT-I training programs that prepare clinicians to sit for the CBT-I certification examination. It\u2019s an effort to move CBT-I from a treatment that most patients can\u2019t easily access to one that\u2019s more integrated into standard care. Pigeon and his team, meanwhile, are studying and supporting the development of CBT-I apps that can benefit anyone struggling with insomnia, no clinician\u2019s waiting list required.\r\n\r\nAt the public health level, Connolly and Cromwell have both been longtime advocates for adolescent sleep health. Circadian shifts in adolescence mean teens are biologically primed to sleep and wake later\u2014and research suggests 70 percent still aren\u2019t getting enough sleep. Last year, Cromwell talked to congressional staffers as a representative of the American Academy of Sleep Medicine<\/a>, urging them to consider policy changes, including later high school start times to support adolescent sleep and health.\r\n\r\nAs Nedergaard continues the global conversation she started more than a decade ago about why sleep matters, her URochester colleagues carry on their own work to understand sleep\u2019s impact, treat its related disorders, and make sure all of us are getting what we need from it. Their discoveries are reshaping the field, and their advocacy is making sure those discoveries don\u2019t stay locked inside it.\r\n\r\nThat should make all of us rest a little easier.","background_color":"#ffffff","width":"width-medium"},{"acf_fc_layout":"text","anchor":"","css_class":"","title":"
Hush now<\/h3>","content":"Lullabies don\u2019t just soothe us to sleep\u2014they reveal what we fear in the dark.<\/strong>\r\n\r\nSleep is a leap of faith. Lullabies are how we make it feel safe: gentle melodies, whispered reassurances, the musical equivalent of dimming the lights. But as Matthew BaileyShea<\/a>\u2019s research suggests, they\u2019ve always carried a double meaning\u2014comfort on the surface, anxiety just beneath it.\r\n\r\nThe professor of music, who is currently writing a book tentatively titled Troubled Sleep: The Dark Side of Lullabies in Rock, Broadway, and Beyond<\/em>, offers a few selections from across centuries (and genres). \u2014Sofia Tokar \u201920W (MS)<\/em>\r\n\r\n