Control Pain & Heal Faster With Your Brain

00:00:00.000 | - Welcome to Huberman Lab Essentials,

00:00:02.320 | where we revisit past episodes

00:00:04.380 | for the most potent and actionable science-based tools

00:00:07.560 | for mental health, physical health, and performance.

00:00:10.320 | I'm Andrew Huberman,

00:00:12.680 | and I'm a professor of neurobiology and ophthalmology

00:00:16.020 | at Stanford School of Medicine.

00:00:17.720 | Let's continue our discussion about neuroplasticity,

00:00:21.660 | this incredible feature of our nervous system

00:00:23.580 | that allows it to change itself in response to experience,

00:00:26.800 | and even in ways that we consciously

00:00:29.960 | and deliberately decide to change it.

00:00:32.240 | Most people don't know how to access neuroplasticity,

00:00:35.120 | and so that's what this entire month

00:00:37.080 | of the Huberman Lab podcast has been about.

00:00:39.240 | We've explored neuroplasticity

00:00:41.240 | from a variety of different perspectives.

00:00:43.940 | We talked about representational plasticity.

00:00:45.920 | We talked about the importance of focus and reward.

00:00:48.660 | We talked about this amazing and somewhat surprising aspect

00:00:52.000 | of the vestibular system,

00:00:53.620 | how altering our relationship to gravity,

00:00:57.400 | and in addition to that, making errors, as we try and learn,

00:01:01.120 | can open up windows to plasticity.

00:01:03.320 | But we have not really talked so much

00:01:06.300 | about directing the plasticity toward particular outcomes,

00:01:09.480 | and thus far, we really haven't talked yet

00:01:13.680 | about how to undo things that we don't want.

00:01:17.800 | And so today, we are going to explore

00:01:20.240 | that aspect of neuroplasticity,

00:01:22.400 | and we are going to do that in the context

00:01:25.320 | of a very important and somewhat sensitive topic,

00:01:28.760 | which is pain, and in some cases,

00:01:31.160 | injury to the nervous system.

00:01:33.260 | We, as always here on this podcast,

00:01:36.240 | are going to discuss some of the science,

00:01:38.040 | we get into mechanism,

00:01:39.720 | but we also really get at principles.

00:01:43.840 | Principles are far more important than any one experiment

00:01:47.600 | or one description of mechanism,

00:01:49.220 | and certainly far more important than any one protocol,

00:01:52.300 | because principles allow you to think

00:01:54.180 | about your nervous system and work with it

00:01:56.420 | in ways that best serve you.

00:01:58.400 | So let's start our discussion about pain

00:02:01.880 | and the somatosensory system.

00:02:04.140 | The somatosensory system is, as the name implies,

00:02:07.720 | involved in understanding touch,

00:02:10.960 | physical feeling on our body.

00:02:13.480 | And the simplest way to think

00:02:14.880 | about the somatosensory system

00:02:16.280 | is that we have little sensors,

00:02:18.800 | and those sensors come in the form of neurons, nerve cells,

00:02:22.060 | that reside in our skin

00:02:23.480 | and in the deeper layers below the skin.

00:02:25.660 | We have some that correspond to,

00:02:29.160 | and we should say respond to mechanical touch.

00:02:32.760 | So, you know, pressure on the top of my hand,

00:02:35.680 | or a pinpoint, or other sensors, for instance,

00:02:39.480 | respond to heat, to cold.

00:02:41.760 | Some respond to vibration.

00:02:44.680 | We have a huge number of different receptors in our skin,

00:02:48.400 | and they take that information

00:02:51.000 | and send it down these wires that we call axons

00:02:54.200 | in the form of electrical signals to our spinal cord

00:02:56.740 | and then up to the brain.

00:02:58.140 | And within the spinal cord and brain,

00:03:00.680 | we have centers that interpret that information,

00:03:03.560 | that actually make sense of those electrical signals.

00:03:05.720 | And this is amazing because none of those sensors

00:03:09.580 | has a different, unique form of information that it uses.

00:03:12.880 | It just sends electrical potentials into the nervous system.

00:03:15.660 | Pain and the sensation of pain is, believe it or not,

00:03:20.580 | a controversial word in the neuroscience field.

00:03:23.580 | People prefer to use the word nociception.

00:03:26.360 | Nociceptors are the sensors in the skin

00:03:29.700 | that detect particular types of stimuli.

00:03:33.220 | It actually comes from the Latin word nocera,

00:03:35.220 | which means to harm.

00:03:36.540 | And why would neuroscientists not want to talk about pain?

00:03:39.060 | Well, it's very subjective.

00:03:40.820 | It has a mental component and a physical component.

00:03:44.380 | We cannot say that pain is simply an attempt

00:03:48.500 | to avoid physical harm to the body.

00:03:51.260 | And here's why.

00:03:52.700 | They actually can be dissociated from one another.

00:03:55.460 | And there's a famous case that was published

00:03:58.100 | in the British Journal of Medicine

00:04:00.180 | where a construction worker,

00:04:02.780 | I think he fell, is how the story went,

00:04:06.060 | and a 14-inch nail went through his boot

00:04:11.060 | and up through the boot.

00:04:12.620 | And he was in excruciating pain,

00:04:15.640 | just beyond anything he'd experienced.

00:04:17.860 | He reported that he couldn't even move in any dimension,

00:04:21.220 | even a tiny bit, without feeling excruciating pain.

00:04:24.140 | They brought him into the clinic, into the hospital.

00:04:27.200 | They were able to cut away the boot,

00:04:28.900 | and they realized that the nail had gone between two toes

00:04:32.600 | and it had actually not impaled the skin at all.

00:04:35.940 | His visual image of the nail going through his boot

00:04:39.980 | gave him the feeling, the legitimate feeling,

00:04:43.920 | that he was experiencing the pain

00:04:46.020 | of a nail going through his foot,

00:04:47.380 | which is incredible because it speaks

00:04:49.340 | to the power of the mind in this pain scenario.

00:04:53.060 | And it also speaks to the power of the specificity.

00:04:56.660 | It's not like he thought that his foot was on fire.

00:04:58.700 | He thought because he saw a nail going through his foot,

00:05:01.860 | well, it was going through his boot,

00:05:03.700 | but he thought it was going through his foot,

00:05:05.560 | that it was sharp pain of the sort

00:05:08.420 | that a nail would produce.

00:05:09.660 | It really speaks to the incredible capacity

00:05:12.200 | that these top-down,

00:05:13.700 | these higher-level cognitive functions have

00:05:16.660 | in interpreting what we're experiencing out in the periphery,

00:05:19.820 | even just on the basis of what we see.

00:05:22.200 | So why are we talking about pain

00:05:24.200 | during a month on neuroplasticity?

00:05:27.140 | Well, it turns out that the pain system

00:05:28.860 | offers us a number of different principles

00:05:31.220 | that we can leverage to A, ensure that if we are ever injured

00:05:36.220 | we are able to understand the difference

00:05:38.320 | between injury and pain because there is a difference,

00:05:41.540 | that if we're ever in pain

00:05:42.780 | that we can understand the difference

00:05:44.020 | between injury and pain,

00:05:46.420 | that we will be able to interpret our pain.

00:05:48.580 | And during the course of today's podcast,

00:05:50.540 | I'm going to cover protocols that help eliminate pain

00:05:54.540 | from both ends of the spectrum,

00:05:56.660 | from the periphery at the level of the injury

00:05:59.980 | and through these top-down mental mechanisms.

00:06:03.300 | Believe it or not, we're going to talk about love.

00:06:05.720 | A colleague of mine at Stanford who runs a major pain clinic

00:06:09.940 | is working on and has published quality peer-reviewed data

00:06:15.780 | on the role of love in modulating the pain response.

00:06:20.200 | So what we're talking about today

00:06:21.580 | is plasticity of perception,

00:06:24.020 | which has direct bearing on emotional pain

00:06:28.300 | and has direct bearing on trauma.

00:06:30.260 | So let's get started in thinking about what happens

00:06:34.880 | with pain.

00:06:35.720 | And I will tell you just now that there is a mutation,

00:06:38.940 | a genetic mutation in a particular sodium channel.

00:06:41.460 | A sodium channel is one of these little holes in neurons

00:06:44.700 | that allows them to fire action potentials.

00:06:46.660 | It's important to the function of the neuron.

00:06:48.020 | It's also important for the development of certain neurons.

00:06:50.860 | And there's a particular mutation.

00:06:52.660 | There are kids that are born

00:06:53.840 | without this sodium channel 1.7, if you want to look it up.

00:06:57.560 | Those kids experience no pain, no pain whatsoever.

00:07:01.100 | And it is a terrible situation.

00:07:03.780 | They don't tend to live very long due to accidents.

00:07:06.020 | It's a really terrible and unfortunate circumstance.

00:07:08.580 | In fact, it's reasonable to speculate

00:07:12.120 | that one of the reasons, not all,

00:07:13.540 | but one of the reasons why people might differ

00:07:15.720 | in their sensitivity to pain is by way of genetic variation

00:07:19.440 | in how many of these sorts of receptors that they express.

00:07:23.660 | People who make too much of this receptor

00:07:26.320 | experience extreme pain from even subtle stimuli.

00:07:30.200 | So let's talk about some of the features

00:07:32.620 | of how we're built physically and how that relates to pain

00:07:36.640 | and how we can recover from injury.

00:07:38.920 | So, first of all,

00:07:40.600 | we have maps of our body surface in our brain.

00:07:43.300 | It's called a homunculus.

00:07:45.200 | That representation is scaled

00:07:47.440 | in a way that matches sensitivity.

00:07:50.320 | So the areas of your body that are most sensitive

00:07:53.320 | have a lot more brain real estate devoted to them.

00:07:56.300 | Your back is an enormous piece of tissue

00:07:58.840 | compared to your fingertip,

00:08:00.480 | but your back has fewer receptors devoted to it.

00:08:03.240 | And the representation of your back in your brain

00:08:05.260 | is actually pretty small,

00:08:07.160 | whereas the representation of your finger is enormous.

00:08:10.280 | So how big a brain area is devoted to a given body part

00:08:15.280 | is directly related to the density of receptors

00:08:19.600 | in that body part, not the size of the body part.

00:08:22.000 | You can actually know how sensitive a given body part is

00:08:27.560 | and how much brain area is devoted to it

00:08:30.640 | through what's called two-point discrimination.

00:08:32.760 | You can do this experiment if you want.

00:08:34.000 | I think I've described this once or twice before,

00:08:35.680 | but basically if you have someone put,

00:08:39.000 | maybe take two pens and put them maybe six inches apart

00:08:43.480 | on your back and touch while you're facing away,

00:08:46.620 | and they'll ask you how many points they're touching you

00:08:49.880 | and you say two,

00:08:51.920 | but if they move those closer together, say three inches,

00:08:54.360 | you're likely to experience it as one point of contact.

00:08:57.720 | Whereas on your finger, you could play that game all day.

00:09:01.360 | And as long as there's a millimeter or so spacing,

00:09:04.520 | you will know that it's two points as opposed to one.

00:09:06.800 | And that's because there's more pixels,

00:09:08.240 | more density of receptors.

00:09:10.620 | This has direct bearing to pain

00:09:12.400 | because it says that areas of the body

00:09:14.340 | that have denser receptors

00:09:15.420 | are going to be more sensitive to pain than to others.

00:09:18.700 | So just as a rule of thumb,

00:09:21.000 | areas of your body that are injured,

00:09:22.920 | that are large areas that have low sensitivity

00:09:25.320 | before injury likely are going to experience less pain

00:09:29.840 | and the literature shows will heal more slowly

00:09:34.840 | because they don't have as many cells around

00:09:37.760 | to produce inflammation.

00:09:39.240 | And you might say, wait, I thought inflammation is bad.

00:09:41.880 | Well, one of the things I really want to get across today

00:09:43.920 | is that inflammation is not bad.

00:09:46.820 | Inflammation out of control is bad,

00:09:48.680 | but inflammation is wonderful.

00:09:50.560 | Inflammation is the tissue repair response.

00:09:53.680 | I thought it might be a nice time to just think about

00:09:56.440 | the relationship between the periphery and the central maps

00:09:58.760 | in a way that many of you have probably heard about before,

00:10:00.840 | which will frame the discussion a little bit better,

00:10:04.120 | which is phantom limb pain.

00:10:06.380 | Now, some of you are probably familiar with this,

00:10:07.920 | but for people that have an arm or a leg or a finger

00:10:12.920 | or some other portion of their body amputated,

00:10:16.720 | it's not uncommon for those people to feel

00:10:19.620 | as if they still have that limb or appendage

00:10:22.140 | or piece of their body intact.

00:10:24.240 | And typically, unfortunately,

00:10:27.120 | the sensation of that limb is not one of the limb

00:10:30.040 | being nice and relaxed and just there.

00:10:33.980 | The sensation is that the limb is experiencing pain

00:10:38.200 | or is contorted in the specific orientation

00:10:41.080 | that it was around the time of the injury.

00:10:43.060 | So if someone has a blunt force to the hand

00:10:46.080 | and they end up having their hand amputated,

00:10:47.940 | typically they will continue to feel pain

00:10:50.360 | in their phantom hand, which is pretty wild.

00:10:53.400 | And that's because the representation of that hand

00:10:56.440 | is still intact in the cortex, in the brain.

00:10:59.800 | And it's trying to balance its levels of activity.

00:11:02.840 | Normally it's getting what's called proprioceptive feedback.

00:11:05.800 | Proprioception is just our knowledge

00:11:07.720 | of where our limbs are in space.

00:11:09.200 | It's an extremely important aspect

00:11:11.080 | of our somatosensory system.

00:11:13.260 | And there's no proprioceptive feedback.

00:11:16.220 | And so a lot of the circuits start to ramp up

00:11:18.240 | their levels of activity

00:11:19.480 | and they become very conscious of the phantom limb.

00:11:22.820 | Now, before my lab was at Stanford,

00:11:25.040 | I was at UC San Diego.

00:11:26.160 | And one of my colleagues was a guy,

00:11:28.240 | everyone just calls him by his last name, Ramachandran,

00:11:31.160 | who is famous for understanding this phantom limb phenomenon

00:11:34.480 | and developing a very simple,

00:11:35.840 | but very powerful solution to it

00:11:38.120 | that speaks to the incredible capacity

00:11:41.560 | of top-down modulation.

00:11:43.220 | And top-down modulation,

00:11:44.440 | the ability to use one's brain cognition and senses

00:11:48.160 | to control pain in the body

00:11:49.600 | is something that everyone,

00:11:51.160 | not just people missing limbs or in chronic pain

00:11:53.780 | can learn to benefit from

00:11:54.800 | because it is a way to tap into our ability

00:11:58.160 | to use our mind to control perceptions

00:12:01.760 | of what's happening in our body.

00:12:03.400 | So what did Ramachandran do?

00:12:06.420 | Ramachandran had people who were missing a limb

00:12:11.960 | put their intact limb into a box that had mirrors in it

00:12:16.880 | such that when they looked in the box

00:12:18.760 | and they moved their intact limb,

00:12:21.480 | the opposite limb, which was a reflection of the intact limb

00:12:25.600 | 'cause they're missing the opposite limb,

00:12:27.300 | they would see it as if it was intact.

00:12:30.280 | And as they would move their intact limb,

00:12:32.360 | they would visualize with their eyes

00:12:35.040 | the limb that's in the place of the absent limb,

00:12:39.700 | so this is all by mirrors,

00:12:41.160 | moving around and they would feel immediate relief

00:12:44.800 | from the phantom pain.

00:12:47.400 | And he would tell them and they would direct their hand

00:12:50.400 | toward a orientation that felt comfortable to them.

00:12:54.700 | Then they would exit the mirror box,

00:12:56.440 | they would take their hand out

00:12:59.060 | and they would feel as if the hand was now

00:13:02.140 | in its relaxed, normal position.

00:13:03.720 | So you could get real time in moments

00:13:06.480 | remapping of the representation of the hand.

00:13:09.360 | Now that's amazing.

00:13:10.480 | This is the kind of thing that all of us

00:13:11.800 | would like to be able to do if we are in pain,

00:13:14.020 | because if you do anything for long enough, including live,

00:13:17.480 | you're going to experience pain of some sort.

00:13:19.680 | And this, again, I just want to remind you

00:13:21.520 | isn't just about physical injuries and pain,

00:13:24.080 | this has direct relevance to emotional pain as well,

00:13:27.640 | which we, of course, we'll talk about.

00:13:30.080 | So the Ramachandran studies were really profound

00:13:32.800 | because they said a couple of things.

00:13:34.040 | One, plasticity can be very fast,

00:13:36.720 | that it can be driven by the experience of something,

00:13:40.400 | just the visual experience.

00:13:41.460 | And so this may come as a shock to some of you

00:13:43.920 | and by no means am I trying to be insensitive,

00:13:45.840 | but pain is a perceptual thing

00:13:48.720 | as much as it's a physical thing.

00:13:50.640 | It's a belief system about what you're experiencing

00:13:53.500 | in your body.

00:13:54.340 | And that has important relevance

00:13:55.920 | for healing different types of injury

00:13:57.800 | and the pain associated with that injury.

00:14:00.400 | Now, this brings up another topic,

00:14:02.480 | which is definitely related to neuroplasticity and injury,

00:14:06.160 | but is a more general one that I hear about a lot,

00:14:09.600 | which is traumatic brain injury.

00:14:11.040 | Many injuries are not just about the limb

00:14:13.540 | and the lack of use of the limb,

00:14:15.600 | but concussion and head injury.

00:14:17.680 | But I want to talk a little bit about what is known

00:14:20.820 | about recovery from concussion.

00:14:22.540 | And this is very important

00:14:24.640 | because it has implications for just normal aging as well,

00:14:29.000 | and offset setting some of the cognitive decline

00:14:32.660 | and physical decline that occurs with normal aging.

00:14:36.220 | Typically after TBI,

00:14:37.440 | there's a constellation of symptoms

00:14:39.120 | that many people, if not all people with TBI report,

00:14:41.680 | which is headache, photophobia,

00:14:44.680 | that lights become kind of aversive,

00:14:46.480 | sleep disruption, trouble concentrating,

00:14:48.880 | sometimes mood issues.

00:14:51.280 | There's a huge range,

00:14:52.540 | and of course the severity will vary, et cetera.

00:14:55.940 | It's very clear that regardless of whether or not

00:14:58.680 | there was a skull break,

00:14:59.800 | and regardless of when the TBI happened

00:15:02.040 | and how many times it's happened,

00:15:04.240 | that the system that repairs the brain, the adult brain,

00:15:08.880 | is mainly centered around this lymphatic system

00:15:12.020 | that we call for the brain, the glymphatic system.

00:15:15.200 | It's sort of like a sewer system

00:15:16.880 | that clears out the debris that surrounds neurons,

00:15:21.000 | especially injured neurons.

00:15:22.600 | And the glymphatic system is very active during sleep.

00:15:26.240 | And the glymphatic system is something

00:15:27.920 | that you want very active

00:15:29.300 | because it's going to clear away the debris

00:15:31.100 | that sits between the neurons.

00:15:33.240 | And the cells that surround the connections

00:15:36.320 | between the neurons called the glia,

00:15:38.760 | those cells are actively involved

00:15:40.600 | in repairing the connections

00:15:41.840 | between neurons when damaged.

00:15:44.480 | So the glymphatic system is so important

00:15:49.220 | that many people, if not all people who get TBI,

00:15:52.120 | are told get adequate rest, you need to sleep.

00:15:55.080 | And that's kind of twofold advice.

00:15:56.440 | On the one hand, it's telling you to get sleep

00:15:58.520 | because all these good things happen in sleep.

00:16:00.600 | It's also about getting those people

00:16:03.480 | to not continue to engage in their activity full-time

00:16:06.200 | or really try and hammer through it.

00:16:08.240 | The glymphatic system has been shown

00:16:11.160 | to be activated further in two ways.

00:16:14.760 | One is that sleeping on one side, not on back or stomach,

00:16:19.760 | seems to increase the amount of wash out,

00:16:23.760 | or wash through, I should say, of the glymphatic system.

00:16:27.520 | The other thing that has been shown

00:16:30.200 | to improve the function of the glymphatic system

00:16:33.080 | is a certain form of exercise.

00:16:35.480 | And I want to be very, very clear here.

00:16:37.360 | I will never, and I am not suggesting

00:16:40.060 | that people exercise in any way that aggravates their injury

00:16:45.060 | or that goes against their physician's advice.

00:16:49.040 | However, there's some interesting data

00:16:51.600 | that zone two cardio for 30 to 45 minutes,

00:16:54.880 | three times a week, seems to improve the rates of clearance

00:16:59.880 | of some of the debris after injury.

00:17:03.020 | And in general, injury or no,

00:17:05.280 | to accelerate and improve the rates of flow

00:17:09.420 | for the glymphatic system.

00:17:11.180 | It could be fast walking.

00:17:12.840 | It could be jogging.

00:17:14.160 | If you can do that with your injury safely,

00:17:16.300 | it could be cycling.

00:17:17.460 | And this is really interesting outside of TBI

00:17:19.760 | because what we know from aging

00:17:22.180 | is that aging is a non-linear process.

00:17:24.840 | It's not like with every year of life,

00:17:26.660 | your brain gets a little older.

00:17:28.280 | It has, sometimes it follows

00:17:30.100 | what's more like a step function.

00:17:31.520 | Like you get these big jumps in markers of aging.

00:17:35.160 | I guess that we could think of them as jumps down

00:17:36.860 | because it's a negative thing for most everybody

00:17:39.460 | would like to live longer and be healthier

00:17:41.220 | in brain and body.

00:17:42.100 | And so the types of exercise I'm referring to now

00:17:45.700 | are really more about brain longevity

00:17:48.520 | and about keeping the brain healthy

00:17:50.780 | than they are about physical fitness.

00:17:53.840 | So I think this is really interesting.

00:17:55.240 | And if some of you would like to know the mechanism

00:17:57.340 | or at least the hypothesized mechanism,

00:17:59.900 | there's a molecule called aquaporin four

00:18:03.460 | that is related to the glial system.

00:18:06.460 | So glia, it means glue in Latin,

00:18:08.580 | are these cells in the brain,

00:18:10.220 | the most numerous cells in the brain, in fact,

00:18:12.200 | that in sheath synapses, but they're very dynamic cells.

00:18:14.980 | Aquaporin four is mainly expressed by the glial cell

00:18:17.180 | called the astrocyte.

00:18:18.360 | Astro, it looks like a little star.

00:18:20.460 | Incredibly interesting cells.

00:18:22.200 | And the thing to remember

00:18:24.760 | is that the astrocytes bridge the connection

00:18:27.760 | between the neurons, the synapse,

00:18:32.240 | the connections between them and the vasculature,

00:18:34.660 | the blood system and the glymphatic system.

00:18:37.640 | So this glymphatic system and the glial astrocyte system

00:18:41.640 | is a system that we want chronically active

00:18:44.580 | throughout the day as much as possible.

00:18:46.680 | So low-level walking, zone two cardio,

00:18:48.800 | and then at night during slow wave sleep

00:18:51.080 | is when really when this glymphatic system kicks in.

00:18:54.020 | So that should hopefully be an actionable takeaway

00:18:56.520 | provided that you can do that kind of cardio safely

00:18:59.180 | that I believe everybody should be doing

00:19:01.440 | who cares about brain longevity,

00:19:03.000 | not just people who are trying to get over TBI.

00:19:05.660 | Now I'd like to return a little bit

00:19:07.280 | to some of the subjective aspects of pain modulation

00:19:11.520 | because I think it's so interesting and so actionable

00:19:14.980 | that everyone should know about this.

00:19:17.560 | Our interpretation, our subjective interpretation

00:19:20.140 | of a sensory event is immensely powerful

00:19:22.800 | for dictating our experience of the event.

00:19:26.020 | The molecule adrenaline, when it's liberated into our body,

00:19:30.920 | truly blunts our experience of pain.

00:19:33.860 | We all know the stories of people, you know,

00:19:37.600 | walking, you know, miles on stumped legs,

00:19:40.660 | people doing all sorts of things that were incredible feats

00:19:45.000 | that allowed them to move through

00:19:47.440 | what would otherwise be pain.

00:19:48.920 | And afterward they do experience extreme pain,

00:19:51.560 | but during the event,

00:19:52.400 | oftentimes they are not experiencing pain.

00:19:55.200 | And that's because of the pain blunting effects

00:19:57.800 | of adrenaline.

00:19:58.920 | Adrenaline binding in particular receptors

00:20:00.880 | actually shuts down pain pathways.

00:20:03.520 | People who anticipate an injection of morphine

00:20:08.040 | immediately report the feeling of loss of pain.

00:20:13.040 | Their pain starts to diminish

00:20:14.580 | because they know they're going to get pain relief.

00:20:17.640 | And it's a powerful effect.

00:20:18.920 | Now, all of you are probably saying placebo effect.

00:20:21.080 | Placebo effects are very real.

00:20:22.840 | Placebo effects and belief effects as they're called

00:20:25.920 | have a profound effect on our experience

00:20:28.280 | of noxious stimuli like pain.

00:20:31.160 | And they can also have a profound effect

00:20:32.800 | on positive stimuli

00:20:34.040 | and things that we're looking forward to.

00:20:36.640 | One study that I think is particularly interesting here

00:20:39.480 | is from my colleague at Stanford, Sean Mackey.

00:20:41.420 | They did a neuroimaging study.

00:20:43.200 | They subjected people to pain.

00:20:44.640 | In this case, it was a heat pain.

00:20:46.880 | People have very specific thresholds to heat

00:20:49.440 | at which they cannot tolerate any more heat,

00:20:52.400 | but they explored the extent to which looking at an image

00:20:55.420 | of somebody, in this case, a romantic partner,

00:20:57.920 | that the person loved

00:20:59.280 | would allow them to adjust their pain response.

00:21:03.780 | And it turns out it does, they could tolerate more pain.

00:21:08.760 | And they reported it as not as painful.

00:21:11.620 | That response, that feeling of love internally

00:21:15.800 | can blunt the pain experience to a significant degree.

00:21:20.360 | These are not small effects.

00:21:22.000 | And not surprisingly, how early a relationship is,

00:21:25.400 | how new a relationship is directly correlates

00:21:28.720 | with people's ability, they showed,

00:21:30.920 | to use this love, this internal representation of love,

00:21:35.280 | to blunt the pain response.

00:21:37.600 | So for those of you that have been with your partners

00:21:39.760 | for many years and you love them very much

00:21:41.520 | and you're obsessed with them, terrific.

00:21:43.620 | You have a pre-installed,

00:21:45.880 | well, I suppose it's not pre-installed,

00:21:47.000 | you had to do the work 'cause relationships are work,

00:21:48.900 | but you've got a installed mechanism for blunting pain.

00:21:53.500 | And again, these are not minor effects.

00:21:55.860 | These are major effects.

00:21:57.860 | And it's all going to be through that top-down modulation

00:22:00.360 | that we talked about, not unlike the mirror box experiments

00:22:03.020 | with phantom limb that relieve phantom pain

00:22:05.660 | or some other top-down modulation

00:22:08.460 | in the opposite examples, the nail through the boot,

00:22:10.740 | which is a visual image that made the person think

00:22:12.920 | it was painful when in fact it was painful,

00:22:15.220 | even though there was no tissue damage.

00:22:17.420 | It was all perceptual.

00:22:19.340 | So the pain system is really subject

00:22:21.340 | to these perceptual influences, which is remarkable

00:22:26.020 | because really when we think

00:22:27.300 | about the somatosensory system,

00:22:28.580 | it has this cognitive component,

00:22:29.900 | it's got this peripheral component,

00:22:31.660 | but there's another component,

00:22:33.660 | which is the way in which our sensation,

00:22:36.140 | our somatosensory system is woven in

00:22:37.820 | with our autonomic nervous system.

00:22:39.860 | Independent of love,

00:22:40.940 | we're going to talk about something quite different,

00:22:42.500 | which is putting needles and electricity

00:22:44.620 | in different parts of the body, so-called acupuncture,

00:22:47.120 | something that for many people,

00:22:50.280 | it's been viewed as a kind of alternative medicine,

00:22:55.320 | but now there are excellent laboratories

00:22:57.560 | exploring what's called electroacupuncture and acupuncture.

00:23:01.200 | And I think what you'll be interested in

00:23:02.760 | and surprised to learn is that it does work,

00:23:05.360 | but sometimes it can exacerbate pain

00:23:08.520 | and sometimes it can relieve pain.

00:23:10.720 | And it all does that through very discrete pathways

00:23:13.240 | for which we can really say this neuron connects

00:23:16.340 | to that neuron, connects to the adrenals

00:23:17.960 | and we can tie this all back to dopamine

00:23:20.320 | because in the end, it's the chemicals and neural circuits

00:23:22.860 | that are giving rise to these perceptions

00:23:24.880 | or these experiences rather of things

00:23:26.920 | that we call pain, love, et cetera.

00:23:29.080 | There are actually a lot of really good peer-reviewed

00:23:31.360 | studies supporting the use of acupuncture

00:23:34.320 | for in particular GI tract issues.

00:23:37.600 | In recent years, there's been an emphasis

00:23:41.100 | on trying to understand the mechanism

00:23:43.000 | of things like acupuncture and acupuncture itself,

00:23:45.840 | but as a way to try and understand

00:23:47.520 | how these sorts of practices might actually benefit people

00:23:51.640 | who are experiencing pain or for changing the nervous system

00:23:54.440 | or brain-body relationship in general.

00:23:56.880 | What I want to talk about in terms of acupuncture

00:23:59.040 | is the incredible way in which acupuncture illuminates

00:24:02.780 | the crosstalk between the somatosensory system,

00:24:06.880 | our ability to feel stuff externally,

00:24:10.200 | exteroception, internally, interoception,

00:24:13.040 | and how that somatosensory system is wired in with

00:24:17.880 | and communicating with our autonomic nervous system

00:24:20.240 | that regulates our levels of alertness or calmness.

00:24:24.800 | So this takes us all back to the homunculus.

00:24:27.320 | We have this representation of our body surface

00:24:29.880 | in our brain.

00:24:31.100 | That representation is what we call somatotopic.

00:24:36.200 | And what somatotopy is, is it just means that areas

00:24:40.200 | of your body that are near one another

00:24:42.080 | are represented by neurons that are nearby each other

00:24:45.000 | in the brain.

00:24:46.480 | The connections from those brain neurons

00:24:48.380 | are sent into the body and they are synchronized with,

00:24:53.240 | meaning they cross wire with and form synapses

00:24:57.600 | with some of the input from the viscera,

00:25:01.640 | from our guts, from our diaphragm, from our stomach,

00:25:04.800 | from our spleen, from our heart.

00:25:08.240 | Our internal organs are sending information up

00:25:10.800 | to this map in our brain of the body surface,

00:25:14.000 | but it's about internal information,

00:25:15.720 | what we call interoception,

00:25:17.200 | our ability to look inside or imagine inside

00:25:19.640 | and feel what we're feeling inside.

00:25:21.900 | So the way to think about this accurately

00:25:24.920 | is that our representation of ourself

00:25:27.540 | is a representation of our internal workings,

00:25:30.500 | our viscera, our guts, everything inside our skin,

00:25:33.160 | and the surface of our skin, and the external world.

00:25:37.400 | And those three things are always being combined

00:25:39.200 | in a very interesting, complex, but very seamless way.

00:25:43.360 | Acupuncture involves taking needles

00:25:47.800 | and sometimes electricity and/or heat as well

00:25:50.960 | and stimulating particular locations on the body.

00:25:54.200 | And if somebody has a gastrointestinal issue,

00:25:56.040 | like their guts are moving too quick, they have diarrhea,

00:25:58.620 | you stimulate this area

00:25:59.680 | and it'll slow their gut motility down.

00:26:01.560 | Or if their gut motility is too slow, they're constipated,

00:26:04.240 | you stimulate someplace else and it accelerates it.

00:26:06.400 | And hearing about this, if it sounds kind of to a Westerner

00:26:09.960 | who's not thinking about the underlying neural circuitry,

00:26:13.000 | it could sound kind of wacky.

00:26:14.320 | But when you look at the neural circuitry,

00:26:15.960 | the neuroanatomy, it really starts to make sense.

00:26:18.120 | Intense stimulation of the abdomen, however,

00:26:20.960 | with this electroacupuncture has a very strong effect

00:26:24.780 | of increasing inflammation in the body.

00:26:29.520 | And this is important to understand

00:26:31.680 | because it's not just that stimulating the gut does this

00:26:35.280 | because you're activating the gut area.

00:26:38.000 | It activates a particular nerve pathway

00:26:40.820 | for the aficionados.

00:26:41.800 | It's the splenic spinal sympathetic axis,

00:26:44.400 | if you really want to know,

00:26:45.360 | and it's pro-inflammatory under most conditions.

00:26:49.240 | If, for instance, the person is dealing

00:26:51.000 | with a particular bacterial infection,

00:26:53.040 | that can be beneficial.

00:26:54.840 | And this goes back to a much earlier discussion

00:26:57.760 | that we had on a previous podcast

00:26:59.240 | that we'll revisit again and again,

00:27:01.120 | which is that the stress response

00:27:02.820 | was designed to combat infection.

00:27:04.760 | So it turns out that there are certain patterns

00:27:06.920 | of stimulation on the abdomen

00:27:08.320 | that can actually liberate immune cells

00:27:10.480 | from our immune organs, like our spleen,

00:27:13.480 | and counter infection.

00:27:15.160 | When you stimulate these pathways

00:27:17.040 | that activate in particular the adrenals,

00:27:20.040 | the adrenal gland liberates norepinephrine and epinephrine,

00:27:23.560 | and the brain does as well,

00:27:25.240 | it binds to what are called

00:27:26.260 | the beta noradrenergic receptors.

00:27:28.640 | Okay, so this is really getting kind of down into the weeds,

00:27:30.600 | but the beta noradrenergic receptors activate the spleen,

00:27:34.080 | which liberate cells that combat infection.

00:27:37.000 | That's the short-term quick response.

00:27:39.720 | The more intense stimulation of the abdomen

00:27:42.920 | and other areas can be pro-inflammatory

00:27:47.080 | because of the ways that they trigger certain loops

00:27:50.000 | that go back to the brain

00:27:51.440 | and trigger the sort of anxiety pathways

00:27:53.640 | that exacerbates pain.

00:27:55.400 | So one pathway stimulates norepinephrine and blunts pain,

00:27:58.520 | the other one doesn't.

00:27:59.960 | What does all this mean?

00:28:01.000 | How are we supposed to put all of this together?

00:28:03.040 | Well, there's a paper that was published

00:28:04.360 | in "Nature Medicine" in 2014,

00:28:06.200 | this is an excellent journal,

00:28:07.760 | that describes how dopamine

00:28:11.320 | can activate the vagus peripherally

00:28:13.920 | and norepinephrine can activate the vagus peripherally

00:28:17.880 | and reduce inflammation.

00:28:19.040 | What this means is that there are real maps

00:28:22.120 | of our body surface that when stimulated,

00:28:25.400 | communicate with our autonomic nervous system,

00:28:27.920 | the system that controls alertness or calmness,

00:28:30.600 | and thereby releases either molecules

00:28:33.360 | like norepinephrine and dopamine,

00:28:34.760 | which make us more alert and blunt our response to pain,

00:28:38.800 | and they reduce inflammation.

00:28:41.680 | But there are yet other pathways

00:28:43.120 | that when stimulated are pro-inflammatory.

00:28:46.000 | One of the things that bothers me so much these days,

00:28:49.560 | and I'm not easily irritated,

00:28:51.040 | but what really bothers me

00:28:52.040 | is when people are talking about inflammation,

00:28:54.360 | like inflammation is bad.

00:28:55.480 | Inflammation is terrific.

00:28:56.760 | Inflammation is the reason why cells are called

00:28:59.160 | to the site of injury to clear it out.

00:29:01.040 | Inflammation is what's going to allow you

00:29:03.040 | to heal from any injury.

00:29:04.760 | Chronic inflammation is bad,

00:29:06.960 | but acute inflammation is absolutely essential.

00:29:09.840 | Remember those kids that we talked about earlier

00:29:11.800 | that have mutations in these receptors

00:29:13.720 | that for sensing pain, they never get inflammation.

00:29:16.040 | And that's why their joints literally disintegrate.

00:29:20.120 | It's really horrible

00:29:21.100 | because they don't actually have the inflammation response

00:29:23.660 | because it was never triggered by the pain response.

00:29:26.720 | So I think that the data on acupuncture

00:29:29.560 | are turning out to be very interesting.

00:29:31.640 | Before I continue,

00:29:32.520 | I just thought I'd answer a question that I get a lot,

00:29:36.080 | which is what about Wim Hof breathing?

00:29:38.140 | Wim Hof, also called aka the Iceman,

00:29:41.720 | has this breathing that's similar to TUMO breathing,

00:29:44.640 | as it was originally called,

00:29:45.760 | involves basically hyperventilating

00:29:47.560 | and then doing some exhales and some breath holds.

00:29:49.400 | A number of people have asked me about it

00:29:51.560 | in relation to pain management.

00:29:53.560 | The effect of doing that kind of breathing,

00:29:55.800 | it's not a mysterious effect.

00:29:57.040 | It liberates adrenaline from the adrenals.

00:29:59.360 | When you have adrenaline in your system

00:30:01.240 | and when the spleen is very active,

00:30:03.080 | that response is used to counter infection

00:30:08.760 | and stress counters infection

00:30:11.560 | by liberating killer cells in the body.

00:30:14.440 | You don't want the stress response

00:30:15.560 | to stay on indefinitely, however.

00:30:17.780 | Things like Wim Hof breathing, like ice baths,

00:30:21.520 | anything that releases adrenaline

00:30:23.000 | will counter the infection.

00:30:25.640 | But you want to regulate the duration

00:30:27.780 | of that adrenaline response.

00:30:29.100 | Today, we've talked about a variety of tools,

00:30:30.800 | but I want to center in on a particular sequence of tools

00:30:34.560 | that hopefully you won't need,

00:30:36.700 | but presumably if you're a human being and you're active,

00:30:39.980 | you will need at some point.

00:30:41.520 | It's about managing injury and recovering and healing fast,

00:30:46.520 | or at least as fast as possible.

00:30:48.760 | It includes removing the pain.

00:30:51.760 | It includes getting mobility back

00:30:54.440 | and getting back to a normal life,

00:30:56.800 | whatever that means for you.

00:30:58.560 | I want to emphasize that what I'm about to talk about next

00:31:01.760 | was developed in close consultation with Kelly Starrett,

00:31:05.360 | who many of you probably have heard of before.

00:31:08.600 | Kelly can be found at The Ready State.

00:31:10.360 | He's a formally trained,

00:31:11.800 | so degreed and educated exercise physiologist.

00:31:15.220 | He's a world expert in movement and tissue rehabilitation.

00:31:18.560 | So I asked Kelly, I made it really simple.

00:31:20.520 | I said, okay, let's say I were to sprain my ankle

00:31:23.580 | or break my arm or injure my knee or ACL tear

00:31:26.940 | or something like that, or shoulder injury.

00:31:29.640 | What are the absolute necessary things to do

00:31:32.480 | regardless of situation?

00:31:33.920 | So the first one is a very basic one

00:31:36.840 | that now you have a lot of information to act on,

00:31:39.080 | which is sleep is essential.

00:31:40.440 | And so we both agreed eight hours of sleep would be ideal,

00:31:43.480 | but if not at least eight hours immobile.

00:31:45.640 | So that's a non-negotiable

00:31:47.840 | in terms of getting the foundation

00:31:50.160 | for allowing for glymphatic clearance

00:31:52.220 | and tissue clearance, et cetera.

00:31:53.860 | The other is, if possible,

00:31:55.660 | unless it's absolutely excruciating

00:31:58.320 | where you just can't do it, a 10 minute walk per day.

00:32:00.760 | Of course, you don't want to exacerbate the injury,

00:32:02.840 | at least a 10 minute walk per day and probably longer.

00:32:06.680 | This is where it gets interesting.

00:32:07.900 | I was taught, I learned that when you injure yourself,

00:32:10.460 | you're supposed to ice something,

00:32:11.760 | you're supposed to put ice on it.

00:32:12.840 | But I didn't realize this,

00:32:14.040 | but when speaking to exercise physiologists

00:32:16.800 | and some physicians,

00:32:17.980 | they said that the ice is really more of a placebo.

00:32:21.800 | It numbs the environment of the injury,

00:32:24.900 | which is not surprising,

00:32:25.940 | and will eliminate the pain for a short while,

00:32:28.820 | but it has some negative effects

00:32:31.180 | that perhaps offset its use.

00:32:33.740 | It actually can create some like clotting and sludging

00:32:36.180 | of the tissue and fluids,

00:32:38.780 | which is bad because you want the macrophages

00:32:41.620 | and the other cell types phagocytosing,

00:32:44.380 | eating up the debris and injury

00:32:46.900 | and moving it out of there so that it can repair.

00:32:50.180 | So that was surprising to me,

00:32:51.420 | which made me ask, well, then what about heat?

00:32:53.580 | Well, it turns out heat is actually quite beneficial.

00:32:55.880 | The major effects seem to be explained

00:32:57.980 | by heat improving the viscosity of the tissues

00:33:01.560 | and the clearance and the perfusion of fluid,

00:33:05.700 | blood, lymph, and other fluids out of the injury area.

00:33:09.180 | So all of this might sound just like common sense knowledge.

00:33:11.620 | I always just thought it's ice,

00:33:13.060 | it's non-steroid anti-inflammatory drugs,

00:33:15.580 | it's things that block prostaglandins,

00:33:17.700 | so things like aspirin, ibuprofen, acetaminophen,

00:33:21.200 | those things generally work by blocking things

00:33:23.340 | like they're called the Cox prostaglandin blockers

00:33:28.340 | and things of that sort, things in that pathway.

00:33:31.020 | Those sorts of treatments which reduce inflammation

00:33:35.340 | may not be so great at the beginning

00:33:36.760 | when you want inflammation,

00:33:38.260 | they may be important for limiting pain

00:33:40.360 | so people can be functional at all.

00:33:42.300 | But the things that I talked about today

00:33:44.540 | really are anchored in three principles.

00:33:48.080 | One is that the inflammation response is a good one,

00:33:51.820 | it calls to the site of injury,

00:33:54.600 | things that are going to clean up the injury in bad cells.

00:33:57.500 | Then there are going to be things

00:33:59.580 | that are going to improve perfusion

00:34:01.180 | like the glymphatic system, getting deep sleep,

00:34:04.440 | feet elevated, sleeping on one side,

00:34:07.300 | low level zone two cardio three times a week.

00:34:10.340 | Many people ask me about platelet-rich plasma,

00:34:13.940 | so-called PRP.

00:34:15.580 | They take blood, they enrich for platelets

00:34:18.860 | and then they re-inject it back into people.

00:34:21.040 | Here's the deal, it has never been shown

00:34:23.040 | whether or not the injection itself

00:34:25.320 | is what's actually creating the effect.

00:34:28.080 | The claims that PRP actually contains stem cells

00:34:31.140 | are very, very feeble.

00:34:34.040 | And when you look at the literature

00:34:36.320 | and you talk to anyone expert in the stem cell field,

00:34:39.400 | they will tell you that the number of stem cells in PRP

00:34:43.600 | is infinitesimally small.

00:34:45.520 | Stem cells are an exciting area of technology.

00:34:47.880 | However, there's a clinic down in Florida

00:34:50.880 | that was shut down a couple of years ago

00:34:52.760 | for injecting stem cells harvested from patients

00:34:56.240 | into the eye for macular degeneration.

00:34:58.020 | These were people that were suffering from poor vision.

00:35:01.380 | And very shortly after injecting these stem cells

00:35:04.340 | into the eyes, they went completely blind.

00:35:06.560 | And I'm not here to tell you that you should

00:35:08.280 | or shouldn't do something,

00:35:09.160 | but I do think that anything involving stem cells,

00:35:11.640 | one should be very cautious of.

00:35:13.200 | The major issue with stem cells that I think is concerning

00:35:16.940 | is that stem cells are cells

00:35:20.000 | that want to become lots of different things,

00:35:22.020 | not just the tissue that you're interested in.

00:35:23.800 | So if you damage your knee

00:35:24.780 | and you inject stem cells into your knee,

00:35:27.840 | you need to molecularly restrict those stem cells

00:35:30.480 | so that they don't become tumor cells, right?

00:35:33.380 | A tumor is a collection of stem cells.

00:35:36.000 | One needs to approach this with extreme caution,

00:35:38.840 | even if it's your own blood

00:35:41.080 | or stem cells that you're re-injecting.

00:35:43.440 | So I'm going to close there.

00:35:44.800 | I've talked about a lot of tools today.

00:35:47.560 | I've talked a lot about somatosensation,

00:35:50.680 | about plasticity, about pain, about acupuncture,

00:35:54.320 | some of the nuance of acupuncture, inflammation, stress.

00:35:58.400 | We even talked a little bit about high intensity breathing.

00:36:01.440 | So as always, we take kind of a whirlwind tour

00:36:05.540 | through a given topic, lay down some tools as we go.

00:36:09.900 | Hopefully the principles that relate to pain and injury,

00:36:14.120 | but also neuroplasticity in general,

00:36:16.400 | today in the context of the somatosensory system,

00:36:18.620 | will be of use to all of you.

00:36:20.020 | I don't wish injury on any of you,

00:36:22.780 | but I do hope that you'll take the information,

00:36:25.000 | do with it what you will.

00:36:26.400 | Once again, thanks so much for your time

00:36:28.040 | and attention today.

00:36:29.160 | And as always, thank you for your interest in science.

00:36:31.900 | [upbeat music]

00:36:34.480 | (upbeat music)

Control Pain & Heal Faster With Your Brain | Huberman Lab Essentials

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