[swores]

I can't find free access to the full paper, but here's the abstract (afraid I'm not knowledgeable enough to add to or explain any of it):

"The accumulation of metabolic waste is a leading cause of numerous neurological disorders, yet we still have only limited knowledge of how the brain performs self-cleansing. Here we demonstrate that neural networks synchronize individual action potentials to create large-amplitude, rhythmic and self-perpetuating ionic waves in the interstitial fluid of the brain. These waves are a plausible mechanism to explain the correlated potentiation of the glymphatic flow1,2 through the brain parenchyma. Chemogenetic flattening of these high-energy ionic waves largely impeded cerebrospinal fluid infiltration into and clearance of molecules from the brain parenchyma. Notably, synthesized waves generated through transcranial optogenetic stimulation substantially potentiated cerebrospinal fluid-to-interstitial fluid perfusion. Our study demonstrates that neurons serve as master organizers for brain clearance. This fundamental principle introduces a new theoretical framework for the functioning of macroscopic brain waves."

https://pubmed.ncbi.nlm.nih.gov/38418877/

[salawat]

>Chemogenetic flattening of these high-energy ionic waves largely impeded cerebrospinal fluid infiltration into and clearance of molecules from the brain parenchyma.

Sounds like unsync'd brain waves, (being awake) impedes cerebrospinal fluid flow through the brain.

When asleep, neurons sync their action potentials, acting like a ionized fluid pump, moving old dirty cerebrospinal fluid out, and allowing new, clean in.

Interestingly, when they synthesize that type of ionization using other means, they saw the same increase in fluid movement.

This is my best attempt at translating. Hopefully within 1-2 football fields. The author leaves choice of American or the rest of the world to the reader to decide.

[Staple_Diet]

As someone in this field (research field not football field) I'd say that is an excellent layman explanation.

[parpfish]

I wonder if these waves also help in “resetting” the distribution of ions among the CSF so neurons will continue to have the proper ion gradients for firing their action potentials?

[samstave]

I wonder if this state could be ultrasonically induced to have a "sleep helmet" which can calm and align rhythmic waves? and induce an artificial flush or "power nap"

--

Well, thats basically the trope of every Cybernetic design, with the connectors comming out the back of head/spine...

Like a continual wash which keeps you in this suspended hyper-aware, but calm, rested and focused mental state.

This is why cyborgs have such incredible reflexes.

[0xFEE1DEAD]

Have you seen the video on hn a couple of weeks ago about the scientist using ultrasound to halt the progression of Alzheimer’s and to treat addiction?

Most fascinating video I’ve seen in a long time.

Edit: If you haven’t seen it yet, I highly recommend checking it out https://youtu.be/7BGtVJ3lBdE

[randcraw]

IIRC, the goal of that effort is simply to violate the blood brain barrier, which may have therapeutic value only under very tightly managed circumstances since violating it likely will yield at least as many demerits as merits since the BBB is essential to keep the brain free of blood-borne toxins.

[samstave]

manipulating the blood-brain-barrier is exactly what ALL ssris and medicines affecting the brain do.... DMT, LSD, MDMA etc all deal in these molocules.

If we can create/prevent blood-brain-barrier-"Portals" as it were, via ultrasound - and do so like we do with the gamma knife but with sound waves, it would be more harmonious with our nature. (3/6/9 tesla rhythms and all that)

[samstave]

Thanks! Super interesting... however - I think our understanding of how to properly aim it, and make it resonant in the same way that mythical ancients a read to as have - We dont yet understand the frequencies of being.

[samstave]

Looking into this So I built out CyberKnife building at ECH in 2009...

and was just thinking about the vid you had, and how they are using the ultrasound intersections "at the blood brain barrier

Where exactly is this intersection occurring?

Is it poking a hole in something for the plaque to 'flow through' via the cereberal flush?

--

Ah I have my answer::

The transiant gap created by FUS will last a few hours...

So - here is where a few LLM ideas come to mind - as the gap allows for the flow of the enzymes through for a bit before they heal - what is the optimal location for placing the FUS pulses?

How many FUS pulses required to create the gap is unclear, as is exactly how long it takes for the enzyme flush - however, there is currently (mostly?) single point systems, but multi-point systems are being tested. What would be interesting to determine is if there could be a spatial pattern for placing the gaps, assuming you have a multi-point FUS system, imagine creating (N) FUS gaps simultaniously in a pattern which followed the natural flow of the enzyme flush - such that if the cereberal flush is flowing in a clockwise fashion - openening FUS gaps in accordance with the direction and timing of the enzyme flush's frequency. directed flow FUS animation.

It seems you dont have to explicitly open a gap with a FUS pulse - so can "massage" behavior such that you can direct flow? I guess only depending on the frequency with which you can aim and fire FUS pulses - but if you have multiple FUS sources? you can 'kite' the flow in...

which reinforces this: "In the context of Alzheimer’s disease, post-FUS tracer enhancement phenomena suggest the existence of a brain-wide perivenous fluid efflux pathway in humans4. This could potentially facilitate the drainage of harmful substances

I wonder what the energy consumption per pulse, how many pulses per gap, how many gaps per hour.

https://www.elcaminohealth.org/news/el-camino-hospital-purch...

---

But what would be really interesting is the marriage of a multi point FUS system layered on top of a cyberknife where as the cyberknife uses xrays to track the position of the prostate in order to determing the location of the point its 'knifing' - if you can massage points into position using FUS - maybe a multi-point FUS can hold a prostates target in position in sync with the cyberknifes 'knifing' and validation via xrays?

-- ala:

Focused Ultrasound (FUS) and the Blood-Brain Barrier (BBB): FUS has been shown to disrupt the BBB in a noninvasive, safe, and targeted manner1. The mechanical effects of FUS, namely cavitation, are thought to be the principle cause behind this BBB disruption1. This method of BBB disruption – FUS with microbubbles – has had very promising results1.

CyberKnife and Prostate Treatment: The CyberKnife System uses advanced technologies to track tumors anywhere in the body, while its unique robotic design keeps the radiation on target even while the tumor moves2. Before delivering the radiation beam, the CyberKnife System verifies the exact tumor position then adjusts the robot to precisely target the tumor2. This system is particularly effective for treating prostate cancer345.

Potential Combination of FUS and CyberKnife: In theory, a multi-point FUS system could potentially be used to “hold” a prostate target in position, working in sync with the CyberKnife’s tracking and ‘knifing’. This could potentially enhance the precision of the treatment, as the FUS system could help ensure the prostate remains in the optimal position for the CyberKnife treatment.

[brandensilva]

I wonder if this could help insomniacs. I had some pretty extreme burn out earlier this year that mentally made it so I couldn't sleep. I had to remove as much stress from life as I could and plan an aggressive routine of not working, relaxation, exercise, sleeping exactly on time and personal therapy with my wife to get my mind to shut down at night.

It is pretty grueling how bad it feels to not sleep so a cap like this would at least make it so the build up doesn't kill you from over collecting old fluid excessively.

[eschatology]

I was thinking if we could directly tap and pump fresh cerebrospinal fluid and eliminate sleep

[brandensilva]

It seems neat in theory but I imagine the brain having to operate an additional 8 hours a day might actually accelerate mental decline faster as we age given you would be using it 1/3 more but it is an interesting concept.

[samstave]

Or you just have a slow continuous flow, where the pumping is controlled by the heartbeat - meaning that whatever is pumping the BrainWash 9000(TM) is triggered by the impulses to the heart - however there is some monitoring system which also can slow or increase B9 as needed.

[SturgeonsLaw]

> Here we demonstrate that neural networks synchronize individual action potentials to create large-amplitude, rhythmic and self-perpetuating ionic waves in the interstitial fluid of the brain

This line is the money shot. An action potential is the variable electrical charge of a neuron, and they maintain that charge by containing a certain concentration of ions relative to the surrounding cerebrospinal fluid. This paper proposes that neurons synchonise their charge state, which forces ions to flow in or out of the neurons in bulk, the movement of these ions causing the cerebrospinal fluid to move around, clearing out the accumulated debris.

[niemandhier]

I’d expect that it’s probably not the ion movement but the global electric field, maybe even mechanical effects in the axons.

If you look at the Goldstein-Katz equations you see that the conductivities play an as important role as the concentrations.

Most of the voltage change is driven by changes in conductivities and not concentration changes, the ion movements across the membrane should be negligible.

Off course you have the free ions outside the cells than diffuse in a field gradient.

[walleeee]

*Goldman-(Hodgkin-)Katz equation

[gentleman11]

Do these wave of stimulation cause dreaming as a side effect?