基础要诀：如何掌控你的痛感与快感

欢迎来到《赫伯曼实验室精华》，在这里我们将重温往期节目，探寻最有效、最具实操性的科学工具，助力心理健康、身体健康与表现提升。我是安德鲁·赫伯曼，斯坦福医学院神经生物学与眼科学教授。今天，我们将继续探讨感官系统，聚焦痛觉与快感这对感官体验。痛感与快感犹如连续谱的两端，这个谱系涉及皮肤对外界刺激的检测，以及大脑对这些事件的感知与理解。皮肤是我们最大的感觉器官，也是人体最大的器官。

Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science based tools for mental health, physical health, and performance. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we continue our discussion of the senses and the senses we are going to discuss are pain and pleasure. Pain and pleasure reflect two opposite ends of a continuum, a continuum that involves detection of things in our skin and the perception, the understanding of what those events are. Our skin is our largest sensory organ and our largest organ indeed.

它的体积远超人体其他器官。细想之下这是个奇特器官——它功能多元：既是内脏与外界之间的屏障；又蕴藏神经元，让我们能感知轻柔触碰、温度变化或各类压力；还是我们悬挂饰物的载体。

It is much larger than any of the other organs in our body. And it's an odd organ if you think about it, it has so many functions. It acts as a barrier between our organs and the outside world. It harbors neurons, nerve cells that allow us to detect things like light touch or temperature or pressure of various kinds. And it's an organ that we hang ornaments on.

人们佩戴耳环，用纹身和彩绘装饰皮肤。这个器官既能让我们体验剧痛，也能感受极乐。因此它是多面性的器官，需要大脑以多元方式解读。我们似乎都本能地理解痛感与快感。

People put earrings in their ears. People decorate their skin with tattoos and inks and other things. And it's an organ that allows us to experience either great pain or great pleasure. So it's a multifaceted organ and it's one that our brain needs to make sense of in a multifaceted way. I think we all intuitively understand what pleasure and pain are.

快感本质上是身心的一种感觉，驱使我们追求引发该感觉的事物；而痛感则是另一种身心感觉，通常让我们想要回避某些活动或互动。科学家称之为趋利行为（促使我们产生更多需求）与避害行为（让我们想要远离某事）。如前所述，皮肤是人体最大器官，其遍布着神经元——严谨地说就是微小的神经细胞。

Pleasure generally is a sensation in the body and in the mind that leads us to pursue more of whatever is bringing about that sensation. And pain is also a sensation in the body and in the mind that in general leads us to want to withdraw or move away from some activity or interaction. Scientists would call this appetitive behaviors, meaning behaviors that lead us to create an appetite for more of those behaviors and aversive behaviors, behaviors that make us want to move away from something. The organ that we call the skin, as I mentioned earlier, is the largest organ in our body. And throughout that organ, we have neurons, little nerve cells now to be really technical about it.

通俗来说，这些神经元的胞体（含DNA等核心物质的细胞工厂）实际位于脊髓外侧。沿着脊髓两侧分布着神经元集群——背根神经节（DRG）。神经节即细胞集合体，其独特之处在于会伸出轴突（一种细长神经纤维）分支：一支延伸至皮肤，另一支反向连接大脑与脑干。

And the way I'd like you to understand it is that the so called cell body, meaning the location of a cell in which the DNA and other goodies, the kind of central factory of the cell that actually sits right outside your spinal cord. So all up and down your spinal cord on either side are these little blobs of neurons, little collections of neurons. They're called DRGs, dorsal root ganglia. A ganglion is just a collection or a clump of cells. And those DRGs are really interesting because they send one branch that we call an axon, a little wire out to our skin.

这些神经纤维在皮肤中的分布使其能响应机械力：有些仅对轻柔触碰产生电信号；有些只对重度压迫起反应却对羽毛无感；还有些专司温度感知——对冷热产生反应；另有特定神经元能感应皮肤化学物质。这些神经元精妙地收集全身皮肤各类信息并上传至大脑。

And they have another wire from that same cell body that goes in the opposite direction, which is up to our brain and creates connections within our brain and the so called brainstem. Okay. These wires are positioned within the skin to respond to mechanical forces. So, maybe light touch, some will only send electrical activity up toward the brain in response to light touch. Others respond to coarse pressure to hard pressure, but they won't respond to a light feather.

令人惊叹的是（请思考片刻）：这些神经元使用完全相同的信号语言。无论是响应轻触、冷热还是辣椒素的神经元，都仅对特定刺激产生电信号——但所有电信号本质相同。然而当冰块接触皮肤时，你明确感知寒冷而非误判为灼热或辣椒刺激。

Others respond to temperature. So they will respond to the presence of heat or the presence of cold, and still others respond to other types of stimuli like certain chemicals on our skin. So these neurons are amazing. They're collecting information of particular kinds from the skin throughout the entire body and sending that information up toward the brain. And what's really incredible.

这意味着在痛感与快感的形成机制中，还存在另一个关键要素——大脑。大脑基于经验部分解读这些电信号，但痛快感知也存在与生俱来的硬连线机制：婴儿无需被火焰灼伤过，首次接触就会缩手。痛快系统无需经验积累，只需具备能解析电信号并从中生成所谓痛感与快感的大脑。

I just want you to ponder this for a second. What's really incredible is that the language that those neurons use is exactly the same. The neuron that responds to light touch, sends electrical signals up toward the brain. The neurons that respond to cold or to heat or to habanero pepper, they only respond to the particular thing that evokes the electrical response. I should say that they only respond to the particular stimulus, the pepper, the cold, the heat, etcetera, that will evoke an electrical signal, but the electrical signals are a common language that all neurons use.

这种机制的精妙之处在于：虽然所有神经元使用相同的电信号语言，但大脑能精准区分冷热、触压等不同刺激。这表明在痛感与快感的形成方程中，大脑的解读能力才是核心变量。

And yet if something cold is presented to your skin, an ice cube, you know, that that sensation, that thing is cold. You don't misperceive it as heat or as a habanero pepper. Okay. So that's amazing. What that means is that there must be another element in the equation of what creates pleasure or pain.

最终决定因素是大脑——它通过部分经验依赖的机制，以及完全不需要后天经验的先天硬连线机制（如婴儿天生会躲避火焰），将这些通用电信号转化为我们称之为痛感与快感的主观体验。

And that element is your brain. Your brain takes these electrical signals and interprets them partially based on experience, but also there are some innate, meaning some hardwired aspects of pain and pleasure sensing that require no experience whatsoever. A child doesn't have to touch a flame, once, and the very first time they will withdraw their hand from the flame. The pain and pleasure system don't need prior experience. What they need is a brain that can interpret these electrical signals and somehow create what we call pleasure and pain out of them.

那么涉及大脑哪些部分呢？主要是所谓的体感皮层，即我们新皮层的一部分，位于大脑外部那些凹凸不平的区域。在你的体感皮层中，有一张全身表面的映射图，称为‘小矮人’。这是你触觉（包括愉悦与疼痛）的神经表征，但其分布并非随机。

So what parts of the brain? Well, mainly it's the so called somatosensory cortex, the portion of our neocortex, which is on the outside of our brain, the kind of bumpy part. And in your somatosensory cortex, you have a map of your entire body surface. That map is called a homunculus. It's your representation of touch, including pleasure and pain, but it's not randomly organized.

它以高度特异的方式组织——皮肤表面感觉受体密度越高的区域，在大脑中的映射面积就越大。哪些区域被放大呢？嘴唇、面部、指尖、足部和生殖器。因为这些区域的神经支配（即传入的感觉神经纤维数量）远超身体其他部位。你现在就可以通过‘两点辨别测试’实时体验这一点。

It's highly organized in a very particular way, which is that the areas of your skin that have the highest density of these sensory receptors are magnified in your brain. What are the areas that are magnified? Well, the lips, the face, the tips of the fingers, the feet, and the genitals. And that's because the innervation, the number of wires that go into those regions of your body far exceeds the number of wires for sensation of touch that go to other areas of your body. You can actually experience this in real time right now, by doing a simple experiment that we call two point discrimination.

两点辨别力是指你判断两个压力点是否相邻的能力，有时甚至会误判为单点压力。这个实验需要第二人协助：让对方用两个尖端（如铅笔或笔尾）轻触你。如果你闭眼时，我将两支笔尖以约1厘米间距放在你手背，即使看不见，你仍能感知这是两个独立压力点。但若同样操作在你后背中央，你会感觉这是单个压力点。

Two points discrimination is your ability to know whether or not two points of pressure are far apart near each other, or you actually could perceive incorrectly as one point of pressure. You might want a second person to do this experiment. That person would take two fine points, so it could be two pencils or pens or the backs of pens. If you were to close your eyes and I were to take these two pens and put their points close together about a centimeter apart and present them to the top of your hand, you, even though your eyes were closed, you would be able to perceive that that was two points of pressure presented simultaneously to the top of your hand. However, if I were to do this to the middle of your back, you would not experience them as two points of pressure.

换言之，两点辨别力在感觉受体密集的身体区域更为敏锐。大多数人尚未意识到这种受体密度差异的深远影响——皮肤中的传感器与大脑解读机制共同作用。信不信由你，这种主观解读会极大影响你对愉悦或疼痛的体验。

You would experience them as one single point of pressure. In other words, your two point discrimination is better, is higher on areas of your body, which have many, many more sensory receptors. Most of us don't really appreciate how important and what a profound influence this change in density of receptors across our body surface has. You've got sensors in the skin and you've got a brain that's going to interpret what's going on with those sensors. And believe it or not, your subjective interpretation of what's happening has a profound influence on your experience of pleasure or pain.

有多个因素会影响这些体验，但主要类别包括预期。如果有人提前告知‘这里要打针，可能会疼一下’，与你突然遭遇疼痛的体验将截然不同。

There are several things that can impact these experiences, but the main categories are expectation. If someone tells you this is going to hurt, I'm going to give you an injection right here. It might hurt for a second. That's very different. And your experience of that pain will be very different than if it happened suddenly out of the blue.

焦虑水平（即自主神经兴奋程度）也会影响愉悦或疼痛体验。睡眠质量及昼夜节律阶段同样关键——我们对疼痛的耐受能力在24小时周期内波动显著。正如你所料，白天清醒时我们更能耐受疼痛，也更容易感受愉悦。

There's also anxiety, how anxious or how high or low your level of arousal, autonomic arousal, that's going to impact your experience of pleasure or pain. How well you've slept and where you are in the so called circadian or twenty four hour cycle. Our ability to tolerate pain changes dramatically across the twenty four hour cycle. And as you can imagine, it's during the daylight waking hours that we are better able to tolerate. We are more resilient to pain and we are better able to experience pleasure.

夜间疼痛阈值大幅降低——即能引发疼痛反应的机械/化学/温度刺激强度，以及我们对疼痛的主观评分都会减弱。特别是凌晨2-5点（假设你遵循标准作息）。最后是基因因素：疼痛阈值及持续时间部分由遗传决定。因此影响因素包括：预期、焦虑、睡眠、昼夜节律阶段和基因。

At night, our threshold for pain is much lower. In other words, the amount of mechanical or chemical or thermal meaning temperature stimulated that can evoke a pain response and how we would rate that response is much lower at night. And in particular in the hours between 2AM and 5AM, if you're on a kind of standard circadian schedule. And then the last one is our genes, pain threshold, and how long a pain response lasts is in part dictated by our genes. So, we have expectation, anxiety, how well we've slept, where we are in the so called twenty four hour circadian time and our genes.

让我们重点讨论预期与焦虑——这两者能强力调节愉悦与疼痛体验，让我们既能放大愉悦感，也能减轻疼痛（如果需要）。在此我想感谢赞助商AG1：这款维生素矿物质益生菌饮品还包含益生元与适应原。作为深耕科研与健康领域近三十年的从业者，我持续寻找提升身心健康的最佳工具。早在2012年（远早于我做播客时）就开始每日服用AG1。

So, let's talk about expectation and anxiety because those two factors can powerfully modulate our experience of both pleasure and pain in ways that will allow us to dial up pleasure if we like and to dial down pain, if indeed that's what we want to do. I'd like to take a quick break and acknowledge our sponsor AG1. AG1 is a vitamin mineral probiotic drink that also includes prebiotics and adaptogens. As somebody who's been involved in research science for almost three decades and in health and fitness for equally as long, I'm constantly looking for the best tools to improve my mental health, physical health, and performance. I discovered AG1 back in 2012, long before I ever had a podcast and I've been taking it every day since.

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那么我们来谈谈预期与焦虑，因为这两者存在某种关联。目前多项可靠实验表明，若我们预知疼痛刺激即将到来，就能在心理上更好地准备，从而缓冲或减轻痛感反应。关键在于，如果受试者提前获知疼痛将至，其主观痛感会大幅降低。但若仅在疼痛来临前两秒才警告，不仅无益反而会加剧痛感。

So let's talk about expectation and anxiety because those two things are somewhat tethered. There are now a number of solid experiments that point to the fact that if we know a painful stimulus is coming, that we can better prepare for it mentally and therefore buffer or reduce the pain response. Essentially, if subjects are warned that a painful stimulus is coming, their subjective experience of that pain is vastly reduced. However, if they are warned just two seconds before that pain arrives, it does not help. It actually makes it worse.

原因在于两秒的短暂时间窗口不足以进行心理准备。同理，若提前两分钟预警疼痛刺激，也会适得其反——因为预期会加剧自主神经系统的唤醒状态，所有警觉性都聚焦于即将到来的负面体验。那么，若要减轻痛感，我们该提前多久获知疼痛刺激？答案大约是二十到四十秒之间最为适宜。

And the reason is they can't do anything mentally to prepare for it in that brief two second window. Similarly, if they are warned about pain, that's coming two minutes before a painful stimulus is coming, that also makes it worse because their expectation ramps up the autonomic arousal. The level of alertness is all funneled toward that negative experience that's coming. So, how soon before a painful stimulus should we know about it if the goal is to reduce our level of pain? And the answer is somewhere between twenty seconds and forty seconds is about right.

这一发现在多种情境中都具实用价值，但更重要的是它揭示：痛觉绝非仅源自皮肤接收的信号模式。必然存在主观解释成分，因为每个人的痛阈各不相同。首先，何为痛阈？它包含两个维度：第一维度是机械、化学或热刺激的强度阈值——即达到你、我或他人喊出'我受不了了'的临界点。

This can come in useful in a variety of contexts, but I think it's important because what it illustrates is that it absolutely cannot be just the pattern of signals that are arriving from the skin. There has to be a subjective interpretation component because we are all different in terms of our pain threshold. First of all, what is pain threshold? Pain threshold has two dimensions. The first dimension is the amount of mechanical or chemical or thermal stimulation that it takes for you or me or somebody else to say, I can't take that anymore.

但还有第二维度：疼痛持续时长。为直观展现个体痛觉体验的差异，让我们看个实验。斯坦福医学院等机构曾让受试者将手浸入冰水中，记录其坚持时长，并要求用1-10分评估痛感强度。

I'm done. But there's another element as well, which is how long the pain persists. And to just really point out how varied we all are in terms of our experience of pain, let's look to an experiment. There have been experiments done at Stanford school of medicine and elsewhere, which involved having subjects put their hand into a very cold vat of water and measuring the amount of time that they kept their hand in that water. And then they would tell the experimenter how painful that particular stimulus was on a scale of one to 10.

这个简单实验显示，人们对相同低温刺激的体验天差地别：有人评为10级剧痛，有人觉得 barely painful（勉强算1级），还有人评为3级、5级等。事实上，疼痛不存在客观衡量标准。同理，我们常谈论快感，却只能通过语言报告来揣度他人的真实体验。

That simple experiment revealed that people experienced the same thermal in this case, cold stimulus vastly different. Some people would rate it as a 10 out of 10 extreme pain. Other people would rate it as barely painful at all, like a one, other people, a three, other people, a five, etcetera. In fact, there is no objective measure of pain. Similarly, pleasure is something that we all talk about, but we have no way of gauging what other people are experiencing, except what they report through language.

与其局限于痛觉的主观性，不如探讨疼痛与快感的绝对特性，从而学会更好地驾驭这两种体验。首先谈谈冷热感知：皮肤中的确存在冷热感受器。测试疼痛耐受力最直接的方式就是让人进行冰浴——有人迅速入水，有人缓慢适应。

So rather than focus on just the subjective nature of pain, let's talk about the absolute qualities of pain and the absolute qualities of pleasure so that we can learn how to navigate those two experiences in ways that serve us each better. First of all, I want to talk about heat and cold. We do indeed have sensors in our skin that respond to heat and cold. And one of the best tests of how somebody can handle pain is to ask them to just get into an ice bath. Some do it quickly, some do it slowly.

还有些人因极度畏寒而始终无法入水。需要了解的是：虽然缓慢入水在心理上更舒适，但从神经生物学角度看反而更糟。冷觉神经元对温度相对变化（而非绝对值）敏感，因此一次性入水能避免大脑接收逐级温度变化的信号。

Others find the experience of cold to be so aversive that they somehow cannot get themselves in. I think it can be helpful to everyone to know that even though it feels better at a mental level to get into the cold slowly, it is actually much worse from a neurobiological perspective. The neurons that sense cold respond to what are called relative drops in temperature. So, it's not about the absolute temperature of the water, it's about the relative change in temperature. Therefore, you can bypass these signals going up to the brain with each relative change, one degree change, two degrees change, etcetera, by simply getting in all at once.

事实上，当冷水浸至颈部时，其舒适度远高于半身入水状态——这是因为上半身（暴露）与下半身（浸水）的冷觉受体信号存在差异。当然，并非鼓励人们贸然跳入陌生水域（极端低温可能引发心脏病），但在安全前提下，快速浸没至颈部的确更容易适应。

In fact, it is true that if you get into cold water up to your neck, it's actually much more comfortable than if you're halfway in and halfway out. And that's because of the difference in the signals that are being sent from the cold receptors on your upper torso, which is out of the water and your lower torso. Now, wouldn't want anyone to take this to mean that they should just jump into an unknown body of water. People can have heart attacks from getting into extremely cold water, but it is absolutely true that provided it's safe, getting into a cold water is always going to be easier to do quickly. And it's going to be easier to do up to your neck.

而热觉恰好相反：神经元以绝对值衡量热度，因此渐进式接触热源更为合理，需找到安全舒适（或至少安全范围内可耐受）的阈值。理解痛觉主观性的最佳例证，莫过于痛感与身体损伤程度并不总成正比——《英国医学杂志》记载：某建筑工人从二楼坠落时，目睹钉子贯穿靴子而剧痛难忍。

Now, heat is the opposite. Heat is measured in absolute terms by the neurons. So gradually moving into heat makes sense and finding that threshold, which is safe and comfortable for you, or if it's uncomfortable, at least resides within that realm of safety. One of the most important things to understand about the experience of pain and to really illustrate just how subjective pain really is, is that our experience of pain and the degree of damage to our body are not always correlated. A classic example of this was published in the British journal of medicine in which a construction worker fell from, I think it was a second story, which he was working and a nail went up and through his boot and he looked down and he saw the nail going through his boot and he was in absolute excruciating pain.

送医后因钉子过长，医护人员不得不剪开靴子，却发现钉子仅从两趾间穿过——未造成任何穿刺伤。但视觉上'钉子贯穿足部'的认知已足够引发剧烈痛觉。当患者意识到真相时，疼痛瞬间烟消云散。

They took him to the hospital and because the nail was so long and because of where it had entered exited the boot, they had to cut away the boot in order to get to the nail. And when they did that, they revealed that the nail had passed between two of his toes. It had actually failed to impale his body in any way. And yet the view, the perception of that nail entering his boot at one end and exiting the boot at the other was sufficient to create the experience of a nail that had gone through his foot. And the moment he realized that that nail had not gone through his foot, the pain completely evaporated.

我想特别强调所谓的心理生理现象。有时我们听到‘心身性’这个词，会理解为‘全在脑子里’，但重要的是记住一切其实都是神经性的——无论是因开放性伤口大出血导致的躯体疼痛，还是无法用任何损伤解释的疼痛，都由神经系统介导。所以讨论身体、大脑或心身性本质上是无意义的，希望未来我们能摒弃这种表述。例如当患者带着‘综合征’就诊——像极具争议的慢性疲劳综合征——部分医生认为它反映真实病理基础，另一些则持否定态度。

And I want to make sure that I emphasize the so called psychosomatic phenomenon. I think sometimes we hear psychosomatic and we interpret that as meaning all in one's head, but I think it's important to remember that everything is neural, whether or it's pain in your body, because you have a gaping wound and you're hemorrhaging out of that wound, or whether or not it's pain for which you cannot explain it on the basis of any kind of injury, it's all neural. So, saying body, brain, or psychosomatic, it's kind of irrelevant. And I hope someday we move past that language. So, when we hear syndrome and a patient comes into a clinic and says that they suffer for instance, from something which is very controversial, frankly, like chronic fatigue syndrome, some physicians believe that it reflects a real underlying medical condition, others don't.

但‘综合征’仅代表我们认知不足，而非病症不存在。比如纤维肌痛（全身性疼痛）长期被医学界归为‘无法解释的综合征’而遭忽视。如今我们至少已确认其一种病理基础——神经胶质细胞的激活。

However, syndrome means we don't understand. And that doesn't mean something doesn't exist. Fibromyalgia or whole body pain for a long time was written off or kind of explained away by physicians and scientists, frankly, my community, as one of these syndromes, it couldn't be explained. However, now there is firm understanding of at least one of the bases for this whole body pain. And that's activation of a particular cell type called glia.

这些胶质细胞表面存在特定受体（专业术语称Toll样受体），其激活与某些类型的全身疼痛及纤维肌痛相关。目前纤维肌痛的治疗方案中，临床数据显示处方药纳曲酮可能有效。

And there's a receptor on these glia, for those of you that want to know called receptor. And activation of the toll for receptor is related to certain forms of whole body pain and fibromyalgia. Now, what treatments exist for fibromyalgia? There are clinical data using a prescription drug. The drug is called Naltrexone.

纳曲酮本用于治疗阿片类药物成瘾，但极低剂量时被发现能通过阻断胶质细胞Toll样受体来缓解某些纤维肌痛症状。另一种可选物质是乙酰左旋肉碱，每日1-4克剂量可改善慢性全身疼痛及某些急性疼痛症状。该物质既有500毫克口服胶囊，也可注射使用。

Naltrexone is actually used for the treatment of various opioid addictions and things of that sort, but it turns out that a very low dose has been shown to have some success in dealing with and treating certain forms of fibromyalgia. And it has that success because of its ability to bind to and block these toll free receptors on glia. There's another approach that one could take and that compound is acetyl L carnitine. There is evidence that acetyl L carnitine can reduce the symptoms of chronic whole body pain and other certain forms of acute pain at dosages of somewhere between one to three and sometimes four grams per day. Now, acetyl L carnitine can be taken orally, it's found in five hundred milligram capsules, as well as by injection.

关于乙酰左旋肉碱的研究文献浩如烟海（可通过PubMed或examine.com查阅）。现有证据表明它通过多重机制缓解疼痛，部分高质量研究甚至暗示其可能加速伤口愈合。现在让我们转向一种完全非药物的千年古法。

There are a large number of studies on acetyl L carnitine. You can look those up on PubMed if you like, or on examine.com. So, it appears that L carnitine is impacting a number of different processes, to impact pain and perhaps, and I want to underscore perhaps, but there are good studies happening now, perhaps accelerate wound healing as well. Now, I'd like to turn our attention to a completely non drug non supplement related approach to dealing with pain. And it's one that has existed for thousands of years.

直到近年西方科学界才开始重视针灸，如今已有精妙的机制研究阐释其镇痛原理。斯坦福大学疼痛科主任Sean Mackie医生指出：部分患者针灸后疼痛显著缓解，另一些则收效甚微。多个实验室正探究其作用机制。

And that only recently has the Western scientific community started to pay serious attention to. And there is terrific mechanistic science to now explain how and why acupuncture can work very well for the treatment of certain forms of pain. Now, first off, I want to tell you what was told to me by our director or chief of the pain division at Stanford School of Medicine, Doctor. Sean Mackie, which was that a fraction of people experienced tremendous pain relief from acupuncture and others experienced none at all or very little. A number of laboratories have started to explore how acupuncture works.

哈佛医学院马秋富团队是此领域先驱。他们研究的是电针疗法——并非单纯刺入细针，而是通过导线连接设备施加电流。该团队发现腹部电针会激活交感神经节，通过去甲肾上腺素和神经肽Y发挥作用。

And one of the premier laboratories for this is Chufu Ma's lab at Harvard medical school. Now the form of acupuncture that they explored was one that's commonly in use called electro acupuncture. So this isn't just putting little needles into different parts of the body. These needles are able to pass an electrical current, not magically, but because they have a little wire going back to a device and you can pass electrical current. So, Chufu Ma's lab found was that if electro acupuncture is provided to the abdomen, to the stomach area, It creates activation of what are called the sympathetic ganglia and the activation of these neurons involves noradrenaline and something called NPY neuropeptide Y.

关键在于：腹部电针刺激既可能抗炎也可能促炎，效果取决于电流强度。这种双刃剑特性或许解释了疗效个体差异。但团队进一步研究发现——

The long and short of it is that stimulating the abdomen with electro acupuncture was either anti inflammatory or it could cause inflammation. It could actually exacerbate inflammation depending on whether or not it was of low or high intensity. Now that makes it a very precarious technique. And this may speak to some of the reason why some people report relief from acupuncture and others do not. However, they went a step further and stimulated other areas of the body using electroacupuncture.

下肢电针会激活从腿部延伸至脑干DMV区的神经回路，促使肾上腺释放儿茶酚胺类物质，这些物质具有强力抗炎作用。正确实施的下肢电针不仅能缓解疼痛，还可能通过激活儿茶酚胺通路加速伤口愈合。现在请允许我短暂介绍赞助商Element电解质饮料。

And what they found is that stimulation of the legs caused a circuit, a neural circuit to be activated that goes from the legs up to an area of the base of the brain called the DMV and activated the adrenal glands, which sit atop your kidneys and cause the release of what are called catecholamines. And those were strongly anti inflammatory. In other words, electro acupuncture of the legs and feet can, if done correctly, be anti inflammatory and reduce symptoms of pain and perhaps accelerate wound healing because activations of these catecholaminergic pathways can accelerate wound healing as well. I'd like to take a quick break and acknowledge one of our sponsors Element. Element is an electrolyte drink that has everything you need and nothing you don't.

Element科学配比了钠、镁、钾等必需电解质，且零添加糖分。水合作用对大脑和机体功能至关重要——轻微脱水就会影响认知与体能。电解质更是所有细胞（尤其是神经元）正常运作的关键要素。

That means the electrolytes, sodium, magnesium, and potassium in the correct amounts, but no sugar. Proper hydration is critical for optimal brain and body function. Even a slight degree of dehydration can diminish cognitive and physical performance. It's also important that you get adequate electrolytes. The electrolytes, sodium, magnesium, and potassium are vital for functioning of all the cells in your body, especially your neurons or your nerve cells.

将Element溶解在水中饮用，能非常便捷地确保你获得充足的水分和电解质。为了确保我摄入适量的水分和电解质，我每天早晨醒来时会将一包Element溶解在约16至32盎司的水中，作为起床后的第一件事饮用。在进行任何体育锻炼时，尤其是大量出汗流失水分和电解质的高温天，我也会饮用Element水溶液。Element提供多种美味口味。

Drinking Element dissolved in water makes it very easy to ensure that you're getting adequate hydration and adequate electrolytes. To make sure that I'm getting proper amounts of hydration and electrolytes, I dissolve one packet of Element in about 16 to 32 ounces of water when I first wake up in the morning. And I drink that basically first thing in the morning. I'll also drink Element dissolved in water during any kind of physical exercise that I'm doing, especially on hot days when I'm sweating a lot and losing water and electrolytes. Element has a bunch of great tasting flavors.

我超爱树莓味和柑橘味。现在Element还推出了限量版柠檬ade口味，简直美味绝伦。虽然不想厚此薄彼，但这款柠檬ade口味绝对能和我最爱的树莓/西瓜味并驾齐驱。真的难以抉择，每种口味我都爱。

I love the raspberry, I love the citrus flavor. Right now, Element has a limited edition lemonade flavor that is absolutely delicious. I hate to say that I love one more than all the others, but this lemonade flavor is right up there with my other one, which is raspberry or watermelon. Again, I can't pick just one flavor. I love them all.

若想尝试Element产品，请访问drinkelement.com/huberman或拼写drinklmnt.com/huberman，购买任意Element冲饮产品即可获赠免费试用装。重申一次，通过drinkelement.com/huberman可领取免费试用装。本期节目也由Eight Sleep赞助播出。Eight Sleep智能床垫罩具备制冷、加热和睡眠追踪功能。确保睡眠环境温度适宜是获得优质睡眠的关键。

If you'd like to try Element, you can go to drinkelement.com/hubermanspelleddrinklmnt.com/huberman to claim a free Element sample pack with a purchase of any Element drink mix. Again, that's drinkelement.com/huberman to claim a free sample pack. Today's episode is also brought to us by Eight Sleep. Eight Sleep makes smart mattress covers with cooling, heating, and sleep tracking capacity. One of the best ways to ensure a great night's sleep is to make sure that the temperature of your sleeping environment is correct.

这是因为人体需要降低1-3度体温才能进入并保持深度睡眠，而醒来时体温需回升1-3度才能感觉神清气爽。Eight Sleep会根据你的个性化需求自动整夜调节床温。他们最新推出的Pod 5型号新增多项重要功能，其中一项名为自动驾驶模式。

And that's because in order to fall and stay deeply asleep, your body temperature actually has to drop by about one to three degrees. And in order to wake up feeling refreshed and energized, your body temperature actually has to increase by about one to three degrees. Eight Sleep automatically regulates the temperature of your bed throughout the night according to your unique needs. Eight Sleep has just launched their latest model, the Pod five, and the Pod five has several new important features. One of these new features is called autopilot.

这个AI引擎能学习你的睡眠模式，根据不同睡眠阶段调整环境温度。当检测到打鼾时会抬高头部，还能进行其他优化调整。Pod 5底座内置与App同步的扬声器，可播放助眠音频。音频库包含多段我与Eight Sleep合作录制的NSDR（非睡眠深度休息）引导语。访问eightsleep.com/huberman可享新款Pod 5最高350美元优惠。

Autopilot is an AI engine that learns your sleep patterns to adjust the temperature of your sleeping environment across different sleep stages. Also It elevates your head if you're snoring and it makes other shifts to optimize your sleep. The base on the Pod five also has an integrated speaker that syncs to the Eight Sleep app and can play audio to support relaxation and recovery. The audio catalog includes several NSDR, non sleep deep rest scripts that I worked on with Eight Sleep to record. If you'd like to try Eight Sleep, go to eightsleep.com/huberman to get up to $350 off the new Pod five.

Eight Sleep配送范围覆盖墨西哥、阿联酋等全球多国。再次提醒，通过eightsleep.com/huberman可省最高350美元。现在我们来探讨一个困扰人类数千年的现象——红发人群。你可能听说过红发者痛阈更高，这确实属实。最新研究从机制层面揭示了这一现象。

Eight Sleep ships to many countries worldwide, including Mexico and The UAE. Again, that's eightsleep.com/huberman to save up to $350 Now let's talk about a phenomenon that has long intrigued and perplexed people for probably thousands of years, And that's redheads. You may have heard before that redheads have a higher pain threshold than other individuals. And indeed that is true. There's now a study that looked at this mechanistically.

MC1R基因编码多种蛋白质，其中部分与黑色素生成相关。这解释了为何红发者通常（非绝对）皮肤白皙、常有雀斑且发色红润。该基因通路与我此前在饥饿主题节目中提到的POMC（阿黑皮素原）有关。

There's a gene called the MC1R gene. And this MC1R gene encodes for a number of different proteins. Some of those proteins of course are related to the production of melanin. This is why redheads often not always, but often are very fair skinned, sometimes have freckles, not always, and of course have red hair. This gene, this MC1R gene is associated with a pathway that relates to something that I've talked about on this podcast before, during the episode on hunger and feeding, and this is POMC.

POMC可分解为多种激素，包括增强痛觉的促黑素细胞激素，以及抑制痛觉的β-内啡肽。内啡肽是我们体内自生的类鸦片物质，能减轻特定疼痛感知。虽然不会完全麻木，但确实能降低痛感。

POMC stands for pro opiomelanocortin and POMC is cut up, it's cleaved into different hormones, including one that enhances pain perception. This is melanocyte stimulating hormone and another one that blocks pain beta endorphin. The endorphins are endogenously made, meaning made within our body opioids. They actually make us feel numb in response to certain kinds of pain. Now, completely numb, but they numb or reduce our perception of pain.

所有人都有β-内啡肽和POMC，但红发者体内这类内源性内啡肽更多。这绝不意味着可以给红发者施加更多疼痛，仅表明他们平均痛阈更高（个体存在差异）。值得一提的是，虽然痛阈可以通过冰浴等训练提升，但特定思维模式确实能缓冲疼痛反应。

We all have beta endorphins. We all have POMC, etcetera, but redheads make more of these endogenous endorphins. Now, this of course should not be taken to mean that redheads can tolerate more pain and therefore should be subjected to more pain. All it means is that their threshold for pain on average, not all of them, but on average is shifted higher than that of other individuals. And I should mention, because I mentioned the ice bath that of course pain threshold is something that can be built up, but it does seem that certain patterns of thinking can allow us to buffer ourselves against the pain response.

这并不令人意外——特定思维方式会触发特定神经调质（如多巴胺）的释放。虽然多巴胺看似无所不能，但它实际关联新奇感、预期、动机和奖赏机制（如节目开头所述）。多巴胺调节痛觉的方式其实具有明确的生理基础。

And that should not be surprising. Certain forms of thinking are associated with the release of particular neuromodulators in particular dopamine and dopamine, it may seem is kind of the thing that underlies everything, but it's not. Dopamine is a molecule that's associated with novelty, expectation, motivation, and reward. We talked about this at the beginning of the episode. And the ways in which dopamine can modulate pain is not mysterious.

正是通过激活脑干神经元，与身体各部位沟通，部署如免疫细胞等物质。例如，我们脑干中的神经元可受多巴胺释放调节。这些脑干神经元控制着脾脏等组织或器官释放免疫细胞，这些免疫细胞随后能对抗感染。我们曾听说，快乐时我们更能抵抗感染、应对疼痛及各种挑战，本质上让我们更具韧性——因为多巴胺以神经生物学和生化方式影响特定回路，告知这些细胞与回路当前环境良好，确实能增强适应力。

It's really through the activation of brainstem neurons that communicate with areas of our body that deploy things like immune cells. So for instance, we have neurons in our brainstem that can be modulated by the release of dopamine. And those neurons in the brainstem control the release of immune cells from tissues like the spleen or organs like the spleen. And those immune cells can then go combat infection. We've heard before that when we're happy, we're better able to combat infection, deal with pain, deal with all sorts of things that essentially makes us more resilient because dopamine affects particular circuits and tells in a very neurobiological way, in a biochemical way tells those cells and circuits that conditions are good, and it really does allow for more resilience.

因此，沿着这一思路，我们来谈谈愉悦感。考虑到所有与疼痛相关的细胞、组织和机制，你或许认为我们的整个触觉系统是为感知疼痛、避免组织损伤而设计的。虽然很大比例确实如此，但同样有相当部分专用于我们称为愉悦的体验。这并不意外——愉悦具有适应性功能，这与所有物种的首要目标相关：繁衍后代。

So, along those lines, let's talk about pleasure. With all the cells and tissues and machinery related to pain, you might think that our entire touch system is designed to allow us to detect pain and to avoid tissue damage. And while a good percentage of it is devoted to that, a good percentage of it is also devoted to this thing that we call pleasure. And that should come as no surprise. Pleasure serves an adaptive role and that adaptive role relates to the fact that every species has a primary goal, which is to make more of itself.

否则物种将灭绝。这种繁衍过程（有性生殖）与愉悦感紧密关联。生殖器及其周围分布着最密集的感觉受体，且生殖过程会引发与愉悦相关的感受、分子和认知，这都在意料之中。愉悦的媒介存在于多种化学系统中，但主要是多巴胺系统（负责愉悦预期及实现所需努力）和血清素系统（更直接关联愉悦体验）。从多巴胺和血清素又衍生出催产素等其他激素分子，与伴侣 bonding 相关。

Otherwise it would go extinct. That process of making more of itself, sexual reproduction is closely associated with the sensation and the perception of pleasure. And it's no surprise that not only is the highest density of sensory receptors in and on and around the genitalia, but the process of reproduction evokes sensations and molecules and perceptions associated with pleasure. And the currency of pleasure exists in multiple chemical systems, but the primary ones are the dopamine system, which is the anticipation of pleasure and the work required to achieve the ability to experience that pleasure and the serotonin system, which is more closely related to the immediate experience of that pleasure. And from dopamine and serotonin stem out other hormones and molecules, things like oxytocin, which are associated with pair bonding.

从生化和神经回路层面看，催产素与血清素系统更紧密关联——通常（非绝对）大量分泌血清素的大脑和身体区域，其神经元也常制造并利用催产素。这些化学物质共同创造温暖、幸福和安全感。多巴胺分子则更关联睾酮等激素，以及为获取更多潜在多巴胺释放而进行的追求行为。若血清素和多巴胺水平过低，几乎无法体验愉悦，即所谓快感缺失。

Oxytocin is more closely associated with the serotonin system biochemically and at the circuit level, meaning the areas of the brain and body that manufacture a lot of serotonin, usually not always, but usually contain neurons that also manufacture and make use of the molecule oxytocin. Those chemicals together create sensations of warmth, of well-being, of safety. The dopamine molecule is more closely associated with hormones like testosterone and other molecules involved with pursuit and further effort in order to get more of whatever could potentially cause more release of dopamine. So if levels of serotonin and dopamine are too low, it becomes almost impossible to experience pleasure. There's a so called ahedonia.

这也被描述为抑郁（未必是长期抑郁）。某些药物如安非他酮（常用名）等抗抑郁药，或SSRIs类（如百忧解、舍曲林）会分别提升多巴胺和血清素水平——它们并非增加这些分子的峰值释放量，而是提高其基础水平。想象你的情绪是艘船：若潮水（基础水平）不够高，船便无法离岸航行。

This is also described as depression, although it needn't be long term depression. So certain drugs like antidepressants like Wellbutrin, buprenone, as it's commonly called, or the so called SSRIs, the serotonin selective reuptake inhibitor, excuse me, like Prozac, Zoloft, and similar will increase dopamine and serotonin respectively. They're not increasing the peaks in those molecules. The, what we call the acute release of those molecules. What they're doing is they're raising the overall levels of those molecules.

幸运的是，多数人基础多巴胺和血清素水平正常。大脑和身体用这些通用货币应对不同体验。但若这些水平过低，任何形式的生理或情感愉悦都将难以获得。这就是为何前文提及的治疗可能适用——当然我们无法替你判断，也解释了为何它们有副作用：人为提升愉悦相关分子常导致觅食动力缺失，因血清素升高会削弱对食物的兴趣。

They're raising the sort of foundation or the tide, if you will, think about it as your mood or your pleasure rather is a boat. And if it's on the shore and it can't get out to sea unless that tide is high enough, that's kind the way to think about these tonic levels of dopamine and serotonin. Now, most of us fortunately do not have problems with our baseline or our tonic levels of dopamine and serotonin release. The brain and body use these common currencies for different experiences. So yes, if your dopamine and serotonin, or I should say, your dopamine and or serotonin levels are too low, it will be very hard to achieve pleasure, to experience physical pleasure or emotional pleasure of any kind.

再次强调个体差异巨大。抗抑郁药并非总是有害——它们曾挽救数百万生命，但副作用也可能使其不适用某些人。

That's why treatments of the sort that I described a minute ago might be right for you. Obviously we can't determine if they're right for you. It's also why they have side effects. If you artificially increase these molecules that are associated with pleasure, oftentimes you get a lack of motivation to go seek things like food. People don't get much interest in food because why should they, if their serotonin levels are already up?

因此必须因人而异。简要提醒（因与讨论相关）：无论通过化学、物理、情感或混合方式，都需警惕多巴胺过高——当然过低同样危险。因每当愉悦系统高速运转（如极度狂喜时），疼痛系统会镜像激活。

Again, there's a ton of individual variation. I don't want to say that these antidepressants are always bad. Sometimes they've saved lives. They've saved millions of lives. Sometimes people have side effects that make them not the right choice.

这看似生物学的恶毒诅咒，实则是保护本期开头所述的奖励与动机系统。持续通过物质或行为获取多巴胺看似美妙，但系统终将崩溃——多巴胺大幅升高时，失望感和平衡调节回路也会同步增强。反复暴露于非自然的高强度化学诱导多巴胺峰值后...

So, it has to be determined for the individual. Just briefly, because it's relevant to the conversation that we've been having. You might want to be wary of any experience, any experience, no matter how it arrives, chemical, physical, emotional, or some combination, you might want to be wary of letting your dopamine go too high. And certainly you want to be wary of it going too low because of the way that these circuits adjust. Basically every time that the pleasure system is kicked in, in high gear, an absolutely spectacular event, you cannot be more ecstatic.

（接上文）...系统将最终失衡。当经历化学诱导的多巴胺高峰（非自然美好事件引发的高强度峰值）后，伴随而来的是调控失望感的神经回路强烈激活，这种平衡机制会随着反复暴露于异常高水平多巴胺而逐渐失调。

There is a mirror symmetric activation of the pain system. And this might seem like an evil curse of biology, but it's not, this is actually a way to protect this whole system of reward and motivation that I talked about at the beginning of the episode. It might sound great to just ingest substances or engage in behaviors where it's just dopamine, dopamine, dopamine, and just constantly be motivated, but the system will eventually crash. And so what happens is when you have a big increase in dopamine, you also will get a big increase in the circuits that underlie our sense of disappointment and re adjusting the balance. And with repeated exposure to high levels of dopamine, not naturally occurring wonderful events, but really high chemically induced peaks in dopamine, high magnitude, chemically induced peaks in dopamine.

发生的情况是，面对同样本应令人难以置信的体验，多巴胺的峰值开始逐渐下降、再下降。我们开始出现所谓的习惯化或反应减弱，而痛感却在增强。信不信由你，这其实是一种保护机制，确保我们的安全。但刚才描述的现象，恰恰构成了大多数（如果不是全部）成瘾行为的基础，我们将在未来的节目中深入探讨。今天，我们讨论了皮肤、大脑及身体其他部位控制快乐与痛觉的神经通路。

What happens is those peaks in dopamine start to go down and down and down in response to the same, what ought to be incredible experience. We start to what's called habituate or attenuate, and yet the pain increases in size. And this has a preservative function in keeping us safe, believe it or not. But what I just described is actually the basis of most, if not all forms of addiction, something that we will deal with in a future episode in-depth. So, today we talked about the pathways in the skin and in the brain and elsewhere in the body that control our sense of pleasure and pain.

我们介绍了多种工具，从不同补充剂到电针疗法等各种方法，可用于调节快乐或痛觉感知。当然，思考快乐时，我们必须考虑多巴胺系统、血清素系统及相关化学系统。我意识到本期播客包含大量科学细节，并不指望大家能一次性完全理解。更重要的是掌握基本原则：比如快乐与痛觉如何运作、如何相互作用，以及大脑和体内促成这些感觉并调节其强度的细胞与系统机制。

We described a number of different tools ranging from different supplements to electro acupuncture and various other tools that one could use to modulate your sense of pleasure or pain. And of course, in thinking about pleasure, we have to think about the dopamine system and the serotonin system and some of the related chemical systems. I realized that today's podcast had a lot of scientific details. I don't expect that everyone would be able to understand all these details all at once. What's more important really is to understand the general principles of how something like pleasure and pain work, how they interact and the very cells and systems within the brain and body that allow them to occur and that modulate or change their ability to occur.

当然还有你们对快乐或痛苦的主观体验。希望整体而言，这期内容带给你们的快乐多于痛苦。最后但同样重要的是，感谢你们付出的时间与专注力，也感谢你们对科学的热情。

And of course your subjective experience of pleasure or pain. So I do hope that this was on whole more pleasureful than painful for you. And last but not least, I thank you for your time and attention, and thank you for your interest in science.