中英文稿

你是否睡覺不安穩(wěn)，?感到易躁或者情緒化，?總是忘記一些小事情，?以及感到不堪重負(fù)和孤獨(dú)？?別擔(dān)心，我們都經(jīng)歷過這些。?你可能僅僅是壓力太大。?壓力并不總是件壞事，?它會(huì)在某些時(shí)候幫助你 爆發(fā)額外的能量和專注力，?比如，在進(jìn)行一項(xiàng)競(jìng)技性的運(yùn)動(dòng)?或者必須在公眾面前發(fā)言時(shí)。?但如果壓力一直持續(xù)，?每天我們都接連不斷地承受著壓力，?它就開始實(shí)實(shí)在在地改變你的大腦。?慢性壓力，?比如過度工作或家庭紛爭(zhēng)，?會(huì)影響大腦尺寸、?大腦結(jié)構(gòu)?和大腦功能，?甚至?xí)绊懩愕幕颉?/p>

?壓力開始于一種叫做?下丘腦垂體腎上腺軸的東西，?一連串的相互作用，在大腦的內(nèi)分泌腺和腎臟之間，?它會(huì)控制身體對(duì)壓力的反應(yīng)。?當(dāng)你的大腦檢測(cè)到壓力情況，?你的下丘腦垂體腎上腺軸立刻會(huì)被激活，?并釋放一種叫做皮質(zhì)醇的激素， 提醒你的身體做好立即行動(dòng)的準(zhǔn)備。?但是高水平的皮質(zhì)醇在一段長(zhǎng)時(shí)間過后?會(huì)嚴(yán)重破壞你的大腦。?例如，慢性壓力會(huì)增加你大腦的活動(dòng)水平?和大腦恐懼中心——杏仁體?的神經(jīng)連接數(shù)量。?隨著皮質(zhì)醇水平的上升，?你海馬體里面的電信號(hào)?即大腦中和學(xué)習(xí)、記憶、壓力控制相關(guān)的部分，?開始惡化。?海馬體也抑制了下丘腦腎上腺軸的活動(dòng)，?所以當(dāng)它變?nèi)酰?你控制壓力的能力也隨之變?nèi)趿恕?但是，這還不是全部。?皮質(zhì)醇實(shí)際上可以引起你大腦在尺寸上的萎縮，?過多的皮質(zhì)醇導(dǎo)致神經(jīng)原之間突觸連接減少，?和你額葉前部皮質(zhì)層的萎縮。

?這是你大腦里管理精力集中、?決策制定、?判斷?和社交互動(dòng)的部分。?它也致使海馬體中新生的腦細(xì)胞更少，?這意味著長(zhǎng)期的壓力可能使學(xué)習(xí)和記憶?對(duì)你而言更困難，?同時(shí)也留下了其他更嚴(yán)重的精神問題的隱患，?比如抑郁和最后的老年癡呆癥。?壓力的影響可能直接滲透到你腦部的DNA。

?實(shí)驗(yàn)表明，?一個(gè)雌鼠對(duì)她的孩子培育的情況，?對(duì)于她的孩子在以后的生活中 會(huì)如何應(yīng)對(duì)壓力有一定影響。?被媽媽照顧得細(xì)致的鼠寶寶 會(huì)變得對(duì)壓力比較不敏感，?因?yàn)樗麄兊拇竽X里發(fā)展了更多的皮質(zhì)醇受體，?和皮質(zhì)醇緊密相關(guān)的皮質(zhì)醇受體抑制了應(yīng)激反應(yīng)。?被媽媽粗心大意喂養(yǎng)大的鼠寶寶就有相反的結(jié)果，?所以 這些鼠寶寶在隨后的一生里 都會(huì)對(duì)壓力更加敏感。?這些被認(rèn)為是表觀遺傳變異，?就是說它們?cè)诓恢苯痈幕虼a的前提下，?影響了哪些基因被表現(xiàn)出來。?如果雌鼠媽媽被交換，這些變化就會(huì)對(duì)調(diào)。?但是，還有個(gè)令人驚訝的實(shí)驗(yàn)結(jié)果。?一個(gè)鼠媽媽導(dǎo)致的表觀遺傳變異?會(huì)被傳遞給她后面的好幾代老鼠。?換句話說，這些行為是會(huì)遺傳的。

?但是，也不都是壞消息。?有許多不同的方式 可以改變皮質(zhì)醇對(duì)你緊張的大腦的影響。?最有力的武器是鍛煉和冥想，?因?yàn)樽鲞@些事情的時(shí)候你同時(shí)也會(huì)深呼吸，?并關(guān)心和關(guān)注到你的周遭環(huán)境。?這些活動(dòng)減少了你的壓力?增加了海馬體的大小，?從而改善你的記憶。?所以不要因?yàn)槿粘Ｉ钪械膲毫Χ械酱鞌。?人們只有控制好自己的壓力 才不會(huì)反過來被它控制。

Are you sleeping restlessly,?feeling irritable or moody,?forgetting little things,?and feeling overwhelmed and isolated??Don't worry. We've all been there.?You're probably just stressed out.?Stress isn't always a bad thing.?It can be handy for a burst of extra energy and focus,?like when you're playing a competitive sport,?or have to speak in public.?But when its continuous,?the kind most of us face day in and day out,?it actually begins to change your brain.?Chronic stress,?like being overworked or having arguments at home,?can affect brain size,?its structure,?and how it functions,?right down to the level of your genes.?Stress begins with something called?the hypothalamus pituitary adrenal axis,?a series of interactions?between endocrine glands in the brain and on the kidney,?which controls your body's reaction to stress.?When your brain detects a stressful situation,?your HPA axis is instantly activated?and releases a hormone called cortisol, which primes your body for instant action.?But high levels of cortisol over long periods of time?wreak havoc on your brain.?For example, chronic stress increases the activity level?and number of neural connections in the amygdala,?your brain's fear center.?And as levels of cortisol rise,?electric signals in your hippocampus,?the part of the brain associated with learning, memories, and stress control,?deteriorate.?The hippocampus also inhibits the activity of the HPA axis,?so when it weakens,?so does your ability to control your stress.?That's not all, though.?Cortisol can literally cause your brain to shrink in size.?Too much of it results in the loss of synaptic connections between neurons?and the shrinking of your prefrontal cortex,?the part of your brain the regulates behaviors like concentration,?decision-making,?judgement,?and social interaction.?It also leads to fewer new brain cells being made in the hippocampus.?This means chronic stress might make it harder for you to learn?and remember things,?and also set the stage for more serious mental problems,?like depression and eventually Alzheimer's disease.?The effects of stress may filter right down to your brain's DNA.?An experiment showed?that the amount of nurturing a mother rat provides its newborn baby?plays a part in determining how that baby responds to stress later in life.?The pups of nurturing moms turned out less sensitive to stress?because their brains developed more cortisol receptors,?which stick to cortisol and dampen the stress response.?The pups of negligent moms had the opposite outcome,?and so became more sensitive to stress throughout life.?These are considered epigenetic changes,?meaning that they effect which genes are expressed?without directly changing the genetic code.?And these changes can be reversed if the moms are swapped.?But there's a surprising result.?The epigenetic changes caused by one single mother rat?were passed down to many generations of rats after her.?In other words, the results of these actions were inheritable.?It's not all bad news, though.?There are many ways to reverse what cortisol does to your stressed brain.?The most powerful weapons are exercise and meditation,?which involves breathing deeply?and being aware and focused on your surroundings.?Both of these activities decrease your stress?and increase the size of the hippocampus,?thereby improving your memory.?So don't feel defeated by the pressures of daily life.?Get in control of your stress before it takes control of you.