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The brain's waste clearing lymphatic system shown in people for first time

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Re: The brain's waste clearing lymphatic system shown in people for first time

#101
post #61
post #53

Earlier quoted context omitted.

I’d like to see if anyone with Fatal Familial Insomnia has been treated with this pattern. I expected that insomnia stops this glymphatic clearance, and that’s what eventually kills them.

Isn't it the prions gradually destroying their brain that's killing them?

I’m not aware of the root cause. I thought they just stopped being able to sleep, and the buildup of whatever junk in the brain eventually caused death.

Re: The brain's waste clearing lymphatic system shown in people for first time

#102
post #96

Earlier quoted context omitted.

Yes that’s the position. Good to see it verified in the study. Having a partner and sleeping in the same bed can lead to alterations from the optimal sleeping position, especially sleeping on the back is not good. Sleeping on the back is also one of the main causes of snoring, which often occurs in people which have a big belly and can’t really sleep lateralish anymore. Sleep quality is important too and one big fact…

Is increased glymphatic clearance good or bad?

good

Re: The brain's waste clearing lymphatic system shown in people for first time

#103

There have been a couple of papers [1] that can induce this process while awake using particular image patterns as confirmed in an MRI. I think the NIH confirmation is running behind in the science, independent research is quite a bit ahead of them. I came across the paper on this last year and implemented a very simple page with the parameters they used [2]. There is a number of disease models that show reduced or n…

I work in this field —- You’re mis-construing the research a bit. Your reference talks about CSF flow on a more macroscopic scale (clearance out the fourth ventricle), which is fundamentally different than the glymphatic system referenced in the original story.

Re: The brain's waste clearing lymphatic system shown in people for first time

#104
post #12
post #3

Earlier quoted context omitted.

Looking up “brain MRI with contrast”, the biggest difference seems to be that in a regular MRI the contrast goes to the blood, but here it goes straight to the brain cerebrospinal fluid. You need open brain for that, so indeed doesn’t seem trivial.

Cerebrospinal fluid is produced in the brain, I would imagine that the contrast would end up in newly produced fluid as well, but maybe that assumption is wrong.

Unfortunately no, that is not how the contrast agent gets around. Most Gd agents are huge and don’t leak out of the vasculature unless there is a disruption (tumour etc).

Re: The brain's waste clearing lymphatic system shown in people for first time

#105
post #2

It's taken 12 years to get from "this stuff exists in mice" to "we now know it actually exists in humans and is not vestigial". That seems like a long time. People get brain MRIs with contrast all the time, is there any reason why this never showed up? Because no one was looking? Or because it's a slow mechanism?

Its because we don’t normally inject Gad in CSF. Its kind of wild west to even do so, and these researchers were able to identify this unique dataset and ask some interesting questions.

Re: The brain's waste clearing lymphatic system shown in people for first time

#106

Earlier quoted context omitted.

Paul's animation wasn't playing at an even rate for me, for some reason, so I created two video versions (8Hz and 12Hz) with the 16 second on/off period, starting with an off period, running for 254 seconds, as per the paper. These versions end with an an additional off period, as a 'cool down' from the flicker. Framerate of 24Hz differs from the 120Hz as presented in the paper, but here there is no 40Hz flicker atte…

The idea that watching a video triggers some waste clearing mechanism is pretty wild. Makes me think of Neal Stephenson's Snow Crash where a datafile can be a narcotic or mind virus. Maybe that's not such a crazy idea?

Not wild at all. think of brain cancer (AKA GBM AKA glioblastoms multiforme).

The more you think, the more blood to the brain, the faster the cancer grows.

Think about it.

Re: The brain's waste clearing lymphatic system shown in people for first time

#107
post #97

Earlier quoted context omitted.

I'm interested in how you accomplish this. I can do something along the lines of that by getting myself heated. I actually get a hothead and a tingling comes up to my brain like it's passing in a channel. It could simply be a sensation rising within the brain though, without an actual transport of something. I can focus better after but it doesn't clear my head, just use that frustration or anger to become determined…

I'm not quite sure exactly what I'm doing; it feels a bit like tensing a muscle, but that muscle feels like it's in the middle of my head, a bit toward the back. Obviously there are no actual muscles there, so I'm not sure what's actually happening. If you try raising one eyebrow or wiggling one ear (assuming you can't already do that), you might find that you're briefly activating lots of little muscles around the t…

I sorta get what you're saying, and tbh I've always found it hard to single out a single muscle from all the other tiny muscles around it. I can already raise one eyebrow alone, and I don't remember when I learned to do it so I don't remember the experience, but I do feel that 'single muscle vs many muscles' when I do that.

With the "muscle" in the mid-back of your brain, I understand that much more. If you respond well to meditation and get a sensation from asmr for instance, if we're speaking on the same area, that area gets sensations if the person is more prone to stress.

When I sort of make myself hotheaded, or have any drug, or even really relax, I feel sensations at that area. I wonder if you're the same.

Re: The brain's waste clearing lymphatic system shown in people for first time

#108
post #101
post #61

Earlier quoted context omitted.

Isn't it the prions gradually destroying their brain that's killing them?

I’m not aware of the root cause. I thought they just stopped being able to sleep, and the buildup of whatever junk in the brain eventually caused death.

No, you have the causality reversed. FFI is a prion disease. The insomnia is a consequence of the damage the prion proteins cause. The prions themselves will kill you, regardless of whether you were able to reproduce the biological effects of sleep in a patient. Insomnia is also also caused by other acute brain illnesses, like rabies.

Re: The brain's waste clearing lymphatic system shown in people for first time

#109

There have been a couple of papers [1] that can induce this process while awake using particular image patterns as confirmed in an MRI. I think the NIH confirmation is running behind in the science, independent research is quite a bit ahead of them. I came across the paper on this last year and implemented a very simple page with the parameters they used [2]. There is a number of disease models that show reduced or n…

The paper says they used http://psychtoolbox.org/ to generate the images. > Psychophysics Toolbox Version 3 (PTB-3) is a free set of Matlab and GNU Octave functions for vision and neuroscience research Scientists almost never want to share their code and it makes me sad. Why wouldn't they want to make their paper more easily reproducible?

Because academic code is horrendous.

I once worked in an IT department of a genetics laboratory, which consistently publishes high impact papers in journals like Science and Nature.

While I was there I got to see some of the R/Python/Java code that had been created for all kinds of studies that had taken place there. It was some of the worst code I have ever seen.

But I do agree, the complete methodology including the code should be shared.

Re: The brain's waste clearing lymphatic system shown in people for first time

#110
post #101

Earlier quoted context omitted.

I’m not aware of the root cause. I thought they just stopped being able to sleep, and the buildup of whatever junk in the brain eventually caused death.

No, you have the causality reversed. FFI is a prion disease. The insomnia is a consequence of the damage the prion proteins cause. The prions themselves will kill you, regardless of whether you were able to reproduce the biological effects of sleep in a patient. Insomnia is also also caused by other acute brain illnesses, like rabies.

Ah, smarter today than yesterday. Thx
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