In 1965, 17-year-old high school student, Randy Gardner stayed awake for 264 hours. That's 11 days to see how he'd cope without sleep. On the second day, his eyes stopped focusing. Next, he lost the ability to identify objects by touch. By day three, Gardner was moody and uncoordinated. At the end of the experiment, he was struggling to concentrate, had trouble with short-term memory, became paranoid, and started hallucinating. Although Gardner recovered without long-term psychological or physical damage, for others, losing shuteye can result in hormonal imbalance, illness, and, in extreme cases, death.
En 1965, o estudante de 17 anos, Randy Gardner permaneceu esperto durante 264 horas. Once días para coñecer como reaccionaba sen durmir. O segundo día, a concentración visual diminuíu. Logo, perdeu a capacidade de recoñecer obxectos co tacto. O terceiro día, estaba agresivo e desorientado. Ao final do experimento, tivo dificultades coa concentración, coa memoria a curto prazo, volveuse paranoico e tiña alucinacións. Aínda que se recuperou sen dano psicolóxico nin físico, para outras persoas, o insomnio pode provocar desaxustes hormonais, enfermidades e incluso a morte.
We're only beginning to understand why we sleep to begin with, but we do know it's essential. Adults need seven to eight hours of sleep a night, and adolescents need about ten. We grow sleepy due to signals from our body telling our brain we are tired, and signals from the environment telling us it's dark outside. The rise in sleep-inducing chemicals, like adenosine and melatonin, send us into a light doze that grows deeper, making our breathing and heart rate slow down and our muscles relax. This non-REM sleep is when DNA is repaired and our bodies replenish themselves for the day ahead.
Aínda estamos empezando a entender por que precisamos durmir, mais sabemos que é esencial. As persoas adultas precisan durmir de 7 a 8 horas e os adolescentes preto de 10 horas. Precisamos durmir cando o noso corpo envía sinais de que o noso cerebro está canso e cando vemos que está escuro fóra. O aumento de substancias químicas que inducen o sono, coma a adenosina ou a melatonina, axúdanos a ter un soño lixeiro que se fai máis profundo mentres a respiración e a frecuencia cardíaca diminúen e os nosos músculos se relaxan. O ADN repárase na etapa non REM e o corpo recupera a enerxía para o día seguinte.
In the United States, it's estimated that 30% of adults and 66% of adolescents are regularly sleep-deprived. This isn't just a minor inconvenience. Staying awake can cause serious bodily harm. When we lose sleep, learning, memory, mood, and reaction time are affected. Sleeplessness may also cause inflammation, halluciations, high blood pressure, and it's even been linked to diabetes and obesity.
Nos Estados Unidos de América, estímase que o 30 % dos adultos e o 66 % dos adolescentes sofren de insomnio. Isto é sumamente importante. Estar tantas horas esperto pode causar danos corporais graves. Cando durmimos pouco, a aprendizaxe, a memoria, o ánimo e o tempo de reacción vense afectados. A falta de sono pode causar inflamación, alucinacións, alta presión sanguínea e relaciónase tamén coa diabetes e coa obesidade.
In 2014, a devoted soccer fan died after staying awake for 48 hours to watch the World Cup. While his untimely death was due to a stroke, studies show that chronically sleeping fewer than six hours a night increases stroke risk by four and half times compared to those getting a consistent seven to eight hours of shuteye. For a handful of people on the planet who carry a rare inherited genetic mutation, sleeplessness is a daily reality. This condition, known as Fatal Familial Insomnia, places the body in a nightmarish state of wakefulness, forbidding it from entering the sanctuary of sleep. Within months or years, this progressively worsening condition leads to dementia and death.
En 2014, un afeccionado ao fútbol morreu despois de pasar 48 horas esperto para mirar o Mundial. Aínda que a causa da morte foi un ataque ao corazón, os estudos din que durmir menos de 6 horas cada noite incrementa o risco dun derramo cerebral comparado con durmir entre 6 ou 7 horas. Para quen herdou unha mutación xenética, a falta de sono é unha realidade diaria. Coñécese como «insomnio familiar fatal». O corpo mantense nun estado de vixilia constante, que lle impide durmir placidamente. Co paso dos meses ou anos, a enfermidade pode agravarse dando lugar á demencia ou á morte.
How can sleep deprivation cause such immense suffering? Scientists think the answer lies with the accumulation of waste prducts in the brain.
Como pode o insomnio causar isto? Os científicos sinalan que se debe á acumulación de residuos químicos no cerebro.
During our waking hours, our cells are busy using up our day's energy sources, which get broken down into various byproducts, including adenosine. As adenosine builds up, it increases the urge to sleep, also known as sleep pressure. In fact, caffeine works by blocking adenosine's receptor pathways. Other waste products also build up in the brain, and if they're not cleared away, they collectively overload the brain and are thought to lead to the many negative symptoms of sleep deprivation.
Cando estamos espertos, as células consomen as fontes de enerxía, que se descompoñen en varios produtos, coma a adenosina. Coa acumulación da adenosina, aumenta a necesidade de durmir, coñecida como presión do sono. A cafeína actúa bloqueando as vías dos receptores da adenosina. Tamén se xeran outros residuos no cerebro que, ao non eliminarse, sobrecargan o cerebro e son a causa dos síntomas negativos do insomnio.
So, what's happening in our brain when we sleep to prevent this? Scientists found something called the glymphatic system, a clean-up mechanism that removes this buildup and is much more active when we're asleep. It works by using cerebrospinal fluid to flush away toxic byproducts that accumulate between cells. Lymphatic vessels, which serve as pathways for immune cells, have recently been discovered in the brain, and they may also play a role in clearing out the brain's daily waste products.
Que ocorre no cerebro cando durmimos para evitar isto? Os científicos descubriron o chamado sistema glinfático, un mecanismo de limpeza que elimina esa acumulación e que é máis activo cando durmimos. A través do líquido cefalorraquídeo, drénanse as substancias tóxicas que se acumulan entre as células. Os vasos linfáticos, que serven de ruta de acceso ás células inmunes, descubríronse recentemente no cerebro e parece que tamén axudan ao cerebro a limpar estes residuos diarios.
While scientists continue exploring the restorative mechanisms behind sleep, we can be sure that slipping into slumber is a necessity if we want to maintain our health and our sanity.
Continúase investigando os procesos rexenerativos con respecto ao sono. Podemos estar seguros de que durmir é unha necesidade para manter a nosa saúde física e mental.