15 ms·
The brain makes a lot of waste. Now scientists think they know where it goes
- coppsilgold 2y agoI was able to recreate the audio they used. sox -b 32 -Dr 96k -n 40hz_1ms_pulse_1hour.flac synth 0.001 sin 10k fade t 0.0005 0 0.0005 pad 0.024 repeat 140000 The goal appears to be to stimulate input neurons 40 times a second in order to drive that frequency as deep and as far into the brain as possible. They succeeded in this objective in mice by combining sound, light and touch (through vibrations). The hypothesis is that driving neurons in this way aids in the removal of waste in the brain. It would be nice if they are correct.
- xnx 2y agoIt may sound a little woo woo, but I definitely feels this. After duration of difficult mental work (often difficult reading) I can feel my ability to focus slipping and eyes getting heavy. If I can successfully take a short deep nap (sometimes less than 15 minutes) all that is flushed away and I can focus again. Weird analogy, but a the relief is similar to emptying a full bladder. Related, not napping in these circumstances seems like it would be very unhealthy and damaging.
- mozman 2y agoI love to nap after a brain draining moment. I’m revitalized and ready to go. One of the major WFH benefits.
- adversaryIdiot 2y agoyep, i cant stand in office work
- coffeebeqn 2y agoYep because at the office it will be multiple hours of fighting having to sleep and literally getting nothing done while trying to not appear totally unconscious
- crocowhile 2y agoyes, we've known for two centuries that a couple of hours of extra sleep can help us undo the effects of days and days of sleep deprivation. This is one of the strongest argument against this brain clearance non-sense. If we can get this done in 15 minutes, why sleep 8 hours a day?
- janalsncm 2y agoIt would be an amazing gift to be able to sleep even only half the time every day. That said, I have had the unsettling thought that the brain is never really “off” during your lifetime. With computers you can restart them, but your brain keeps going, even when you’re sleeping. So I think we should be nice to our brains.
- IncreasePosts 2y agoRead more about Intel ME ;)
- crocowhile 2y agoIt would be an amazing gift to you, but it would not make sense from the evolutionary point of view. Take an animal of your choice (e.g. a cat or a dog or a mouse) and give them through magic the ability to sleep only 1 hour a day or nothing for the rest of their life. Do you think they would have an evolutionary advantage? Quite the opposite. they would end up burning more energy for nothing, having to look for more food and eventually endanger themselves to predation wondering, rather than cozy up in their nest sleeping.
- crazygringo 2y agoWhere are you getting 15 minutes from? That might be enough to recharge you to a normal level after something particularly taxing. It's not enough to restore you completely, and certainly not after an entire day's worth of activity. And there's so much more to sleep that you're missing, like consolidating memories, muscular coordination habits and patterns, etc.
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- candiddevmike 2y agoI wonder if they will study the waste buildup of various polyphasic sleep cycles like Everyman.
- therobots927 2y agoI wish I could take naps like that. I’m lucky that I don’t have trouble falling asleep at night but once the sun is up it’s like my brain just refuses to shut off. Once every week or two I’m able to pull off a nap in the late mornings.
- srcreigh 2y agoIt’s not necessary to actually fall asleep. Just set a timer and relax. For me it’s only a semi-conscious pre sleep state, but it helps significantly. Do this if you get tired while driving too. It’s a life saving practice! (And no, driving tired isn’t always due to bad nights sleep. Glucose spikes can be dangerous even if you sleep well at night.)
- therobots927 2y agoI’ll try that! Driving tired scares me. It’s tough when you’re driving through Nebraska for example and places to stop are so spaced out. All of a sudden the sleepiness just hits you and you’re cooked unless you pull over on the side of the highway, which is what you’re supposed to do. How do glucose spikes play into that?
- srcreigh 2y agoIt’s very scary. I hope your Nebraska highways have some exits/side roads you can pull into. I’ll do that sometimes, or find a town and park a gas station somewhere. Glucose spike is referring to the thanksgiving dinner effect where you get tired and need a nap after eating. Feeling tired after lunch. Etc. It can happen after almost any meal, even while well rested, etc. There’s ways to reduce the spikes but afaik once you get the spike, nap is the best solution. Coffee can help for some type of tiredness, but sometimes it’s not enough. I’ll do 15-20 min nap increments. Sometimes one nap isn’t enough, I need to rest longer. Thankfully, I can always tell when the one nap is insufficient before getting on the highway again.
- therobots927 2y ago
- quartesixte 2y agoYou’re not far off the mark. Many jobs/skills that require intense mental concentration report practitioners needing a rest period or having an upper limit to performance. A notable example I remember are the United Nations’ live interpreters. They can only interpret a live conversation for only about 45 minutes before they have to switch off with a new interpreter because the error rate just exponentially goes up due to mental fatigue.
- SoftTalker 2y agoMy dad would say he wished the day was about 30 hours. He liked to work long stretches, 10-12 hours, and then unwind for a few hours and sleep for 12 hours. Unfortunately just didn't work well with the real world.
- JKCalhoun 2y agoEarth, anyway.
- JKCalhoun 2y agoNot weird to me — I feel it too. And I always described it as feeling like a wave of ... release, passing over my mind. It feels wonderful and I wake with a clarity as though a weight were lifted from my mind.
- Grimblewald 2y agoIt might also just be energy stores filling up again. Its like running, if you take a short break you can often get going at a good pace again, not just because you get your breath back but also energy resverse replensih
- akira2501 2y agoWhich makes the "false doctor" voice of my ego say "hmm.. could be pre-diabetes."
- alan-hn 2y agoA little confusing, I thought we've known about the glymphatic system for a while now
- crazygringo 2y agoWhat's confusing? The article is literally about how we've known about the glymphatic system but not what its mechanisms actually are, and this is precisely about now figuring out the mechanisms.
- alan-hn 2y agoThe title. Now we know where it goes, but we knew that already. This article is from this month
- pedalpete 2y agoSurprisingly, the glymphatic system was only discovered a decade ago. The new part is this 40hz light and sound, which has only be done in mice so far.
- alan-hn 2y agoA decade is a very long time in a field as young as neuroscience
- StarterPro 2y ago[flagged]
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- jawon 2y ago"The team used mice that develop a form of Alzheimer's. They exposed these mice to bursts of sound and light that occurred 40 times a second. The stimulation induced brain waves in the animals that occurred at the same, slow frequency. Tests showed that the waves increased the flow of clean cerebrospinal fluid into the brain and the flow of dirty fluid out of the brain. They also showed that the fluid was carrying amyloid, the substance that builds up in the brains of Alzheimer's patients." Does this mean we might be able to use something like TMS instead of sleeping? And could a failure or reduced functioning in this system explain those people "allergic" to electromagnetic radiation?
- treprinum 2y agohttps://www.youtube.com/watch?v=UVne_84qZkA https://www.youtube.com/watch?v=UVne_84qZkA
- dodongobongo 2y ago
- atleastoptimal 2y ago[flagged]
- j1mmie 2y ago> during sleep, slow electrical waves push the fluid around cells from deep in the brain to its surface. Is that what dreams are? Electrical waves and fluid knocking on our brain cells?
- supple-mints 2y agoNo.
- cen4 2y agoRead this book few years back, that dreams are a way of different regions of the brain to defend territory. So the neurons in the visual processing region stop receiving input signal when one sleeps. Those neurons can then be used by neighboring regions for whatever. To prevent that takeover pseudo signals are created to keep them busy. Can't remember the name of the book, but it was a pretty cool theory. EDIT: found the book - Livewired by David Eagleman
- gradientsrneat 2y agoDreams occur during REM sleep.
- j1mmie 2y agoThis also fits well with the theory that lack of deep sleep increases the risk of alzheimers and dementia: https://www.medicalnewstoday.com/articles/not-getting-enough-deep-sleep-may-increase-dementia-risk https://www.medicalnewstoday.com/articles/not-getting-enough...
- clumsysmurf 2y agoJust a few weeks ago this appeared somewhere on HN https://www.sciencealert.com/study-finds-sleep-may-not-flush-toxins-from-the-brain-after-all https://www.sciencealert.com/study-finds-sleep-may-not-flush...
- SubiculumCode 2y agoNot an expert in the field, but from what I understand the idea is very contentious with sizeable camps on both sides, especially noticeable if you are talking to an Alzheimers scientist, or a immune system scientist.
- burning_hamster 2y ago> sizeable camps on both sides There are dozens of us! Mostly because Nedergaard's lab(s) are like 50 people all by themselves. I always find it interesting what people's perception of the size of academic subfields is. For most topics in the biological sciences (i.e. excluding cancer, HIV, malaria, AD, and other "whales") you can fit everyone that has directly worked on that topic in the last 5 years in a medium-sized auditorium. And many people work on multiple topics!
- ashtami8 2y ago@clumsysmurf, nice catch! Could it be possible that the coffee lobby is behind this 'counter'-study?, since a relatively simple inference from the OP has catastrophic consequences for the coffee business: Deep sleep is necessary for the slow electrical waves that clear the brain of waste including amyloid proteins. (Excessive) coffee intake reduces the quality and quantity of deep sleep, thus leading to a build up of waste products including amyloid, resulting in cognitive declines such as Alzheimer's etc. Therefore, coffee intake (indirectly) causes Alzheimer's. Admitting that last part is suicidal for the coffee business.
- hattmall 2y agoSo is this similar to the idea behind 40hz binaural beats?
- skeledrew 2y ago40hz is kinda off the scale, and is for very high concentration, so even though it matches off-hand that's a point to consider.
- gradientsrneat 2y agoThis study was done on mice, so the equivalent frequency for humans (if it exists) is likely lower.
- treprinum 2y agoNo, they used pulses (ta-ta-ta-ta-ta 40 times a second) not continuous waves.
- therobots927 2y agoIt’s pretty incredible that by showing the mice a light and music show, they were able to induce drainage of brain waste. That’s really exciting and I would love it if they could invent a hat to wear at night that accelerated the process while sleeping, effectively multiplying your time spent sleeping by some factor. It could be really effective for people with tough work schedules like doctors, truck drivers and pilots.
- supple-mints 2y agoIf you haven’t already, try taking melatonin before bed. I found my sleep to decrease in length but I wake more rested.
- jdironman 2y agoI feel this will be very subjective of course. The biggest thing I have found I can do for a full rest (not length but quality) is no screens at all after 8pm and no lights except candle light after 930pm, coupled with reading by candle light. Melatonin does help me occasionally but it's hit or miss. Reading instead of watching or listening seems to be the biggest help. I guess different parts of my brain fires during that activity than normal.
- xattt 2y ago> …no lights except candle light after 930pm… I am imagining a household transforming into Amish roleplay by 9:30 PM. I’ve achieved a similar-but-less-impactful effect by putting Zwave dimmer switches where I could, and setting the turn-on brightness to be lower during a “wind-down” house mode.
- p1esk 2y agoFYI, candle light probably makes your air worse.
- vundercind 2y agoI did the same thing for a while, and found it weirdly hard to replace with electricity. Most options are too bright, almost none are incandescent. If I try it again I’ll have to build my own battery powered lanterns with ultra-low-wattage incandescent bulbs (don’t want the spiky spectrum of LED for this purpose) to get them dim enough and in a useful form factor. I could read and get around just fine by two beeswax candles (and after getting used to that, full room lighting seemed insane, it’s so bright) but most things you can buy are at least 5x that bright. Even most plug in night lights are brighter than two beeswax tapers.
- brcmthrowaway 2y agoI wonder how red light on the brain is mixed in with this
- willmadden 2y agoI thought exercise was the key to flushing proteins out of the brain?
- dorkwood 2y agoYeah, I was expecting mention of exercise too.
- aamoyg 2y agoI was going to say onto the Internet as a joke.
- nakedneuron 2y agoGlad you didn't!
- hbarka 2y agoSince it’s a fluid, what about the effect of head angle during sleep?
- skeledrew 2y ago> So finding ways to help the brain clean itself — perhaps by inducing those slow electrical waves — might prevent a wide array of disorders. Even before getting to the end this had me thinking of binaural beats. Back in college there was a beat that I would use whenever I was super tired and had a lot to do, and it'd help me refresh via a quick 20m nap (sometimes the nap itself wasn't even needed; just to let my mind be taken by the beat for the duration). If it's the case that a part of the effect is to trigger a "deep clean" (I've wondered on and off what's really happening), then this just may become a way to reduce said disorders...
- jimmaswell 2y agocould you find the exact one?
- elcritch 2y agoThere are lots of them on YouTube now. I listen to one most nights. Just search for “sleep” and “binaural beats.
- carlbarrdahl 2y agoI'm sure there are differences in their effectiveness. Based on my limited knowledge the sound frequencies attempt to put the brain into theta or delta frequencies and does this by creating a ghost signal (left ear 100hz - right 106hz gives a 6hz theta wave). Dreamachines work similarly (but mono) by creating a flickering light at set frequencies. I'm sure tactile vibrations or pulses could have some effect also.
- numtel 2y agoI made this a few years ago after getting into Hemi Sync tapes to test out what different tones feel like. https://numtel.github.io/binaural-playground/ https://numtel.github.io/binaural-playground/
- skeledrew 2y ago
- mtve 2y agoyou may also check out the quite logical and convincing "Visceral Theory of Sleep": > The visceral hypothesis suggests that during sleep, the central nervous system, particularly the cerebral cortex, switches from analyzing exteroceptive information to analyzing signals arriving from interoceptors distributed throughout all the systems of the body
- phillias 2y agoThis is huge
- EADDRINUSE 2y agoGuess this is a similar mechanism to why brainfog is gone afer a powernap? Lets hope that with enough research one can induce it for the people in need some day.