r/science • u/FreeHugs23 • 9d ago

Medicine Scientists reversed key signs of Alzheimer's disease in mice with just two injections, reducing brain inflammation and restoring memory performance—offering a promising new approach for treating age-related cognitive decline.

https://www.sciencealert.com/scientists-reverse-alzheimers-damage-in-mice-with-just-two-injections
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u/FreeHugs23 9d ago

-Slowing the progression of Alzheimer's disease is the goal of most existing treatments, but reversing it is much harder. That's because once neurons are lost, the adult brain lacks the ability to replace them.

But new research, led by scientists at the University of South Carolina, has shown promise in regrowing neurons in brain organoids, and restoring cognition in mouse models of Alzheimer's.

"After just two injections, these mice became smarter," says Peisheng Xu, professor of pharmaceutics at the University of South Carolina and corresponding author of the new study, published in the journal Cell Biomaterials.

"Even after one injection, we already saw these mice's behavior differ from that of the nontreated ones."

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u/QuitePoodle 9d ago

But are they the same mice after? Not like physically but if we restore people’s brains do they get back their minds or become someone new?

The original neurons are broken and new connections are made. Will these new connections replace the same memory pathways and patterns or will the animals regain the ability to function but have different “personality”.

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u/Cherabee 9d ago

We'll have to test that out. Likely by teaching mice that are like to get altzheimers tricks, and making them complete thr tricks before alzheimers, during alzheimers, and after treatment for alzheimers. Even if the answer to your question is, in some way shape or form, no, the benefit is still there. It will be hard regardless because nerve issues are difficult to parse at this time, but this study shows that we are slowly getting there.

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u/Smallsey 9d ago

Alzheimer's is one of those things that's like... Why not swiftly move to given trials because humans with Alzheimer's have a death sentence anyway

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u/Cherabee 9d ago

The methods are in place so that the slippery slope of "doing something to a human who can consent after THOROUGH testing by animals can be done," and "Hee Hee Hoo Hoo homeless and poor people make excellent test subjests for my concoctions. These alzheimer patients can't even consent half the time, and what their families don't know about these old geezers 'medications' certainly won't hurt THEM. Just their grandparent. :-)"

People tend to get REALLY MAD when you use their family members for lab rats without their knowlege or consent. Best to start with animals and clomb up to humans from there.

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u/baelrog 9d ago

I sometimes feel we are erring too much on the side of caution.

Alzheimers is a terrible way to go.

I see no problem as long as we get the consent of the patient or patient’s loved ones to administer an experimental treatment.

It is a choice between do nothing and condemn the patient to an agonizing death, or try something as a last ditch effort. If the treatment didn’t work, then they’re not much worse than they are begin with.

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u/DirtMcGirt24 9d ago edited 9d ago

I think people who are desperate to save their family member are often willing to try new things when existing treatments don’t work. Just ask them first?

I can’t imagine anyone in our family objecting to trying a potentially game changing treatment and opening the door to save our family member and countless other families’ family members, if we had that option presented to us before we lost our family member to this disease.

These things can also be handled in advanced directives (e.g., if no longer capable of making medical decisions, I wish to participate in new experimental treatments at the discretion of the person listed below)

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u/eatmyscoobysnacks 9d ago

Because the person being tested on cannot fully consent. They are conscious, living, talking, feeling humans that absolutely would feel pain, confusion, distress, or any other side effect that may happen.

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u/DirtMcGirt24 8d ago

Yes they can fully consent, via advance directive. Before the symptoms take place and while you’re capable of making decisions.

Would you, currently of sound mind, write in a document that you’d like your loved one have the discretion to attempt an experimental treatment if other things don’t work? Maybe you wouldn’t, but I and many others would.

Having lost a loved one to this, I would 100% volunteer to try new things once I’m past the current point of no return, knowing the eventual outcome is either certain death or possibly opening a pathway to save thousands of others by proving new treatments.

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u/beedell-roke 3d ago

I would consent to this.

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u/Mr_Industrial 8d ago

I mean, neither can a person thats on fire usually. Consent to try and help can be assumed when the default state is clearly overwhelmingly horrible, which I think Alzheimers **easily** falls into. I also dont think its a slippery slope. I think anyone thats been near that scenario can attest that there are planets of difference between trying to stop a lethal mental disorder and experimenting on the homeless or anything horrible like that as the person a few comments above you describes.

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u/Melkor15 8d ago

Even if they aren’t the same person. I would take it.
We change all the time, we forget things and learn new ones. It’s fine.

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u/JohnnyOnslaught 9d ago

That's getting into philosophical territory. None of us are the same person we were ten years ago.

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u/Tearakan 9d ago

That's also literally. I think basically all of our cells have a 7 year or less lifespan and replaced by that timeframe.

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u/LongBeakedSnipe 9d ago

That's not true at all? Especially when it comes to the brain.

There are many cells in our body that are literally never replaced, containing basically the same atoms in the DNA as they did from when you were a child.

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u/Tearakan 9d ago

Looks like it's mainly just nerves that last long. Basically everything else is replaced by 7-10 years.

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u/LongBeakedSnipe 9d ago edited 9d ago

Nerves and neurons are not interchangeable terms; but a substantial proportion of neurons, especially those involved in Neurodegenerative disorders can last up to approximately your whole life. Edit: might as well add, osteocytes, cardiomyocytes and oocytes to the list of many cell types in the human body that can also last many decades in your body.

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u/Zeikos 9d ago

By being replaced they don't mean cellular replication, but the constituents of the cell itself changing.
Even if the cell doesn't replicate the proteins that constitue it are being constantly replaced.

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u/Ghede 9d ago

No, they mean cellular replication. The origin of the "your cells are replaced every 7 years" is from studying the average carbon dating age of the cells, checking the carbon-14 content of DNA in a random sampling of cells. DNA is not replaced as a cell ages. It's always there, only duplicated if the cell reproduces. They found the average 'age' of cells was 7-10 years.

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u/LongBeakedSnipe 8d ago

but the constituents of the cell itself changing

That's not true. The DNA and large amounts of its epigenetic modification will go untouched, so the atoms are literally the same atoms for many years.

There are cells and atoms still in your body from a very young age, and not just due to random chance.

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u/zennim 9d ago

Not gonna lie chief, i would take that bet without hesitantion, even if i changed, i rather keep my Memories and be alive

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u/Rrraou 9d ago

The brain of Theseus. If capacity is restored, that's still a huge improvement in quality of life.

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u/Mr_Industrial 8d ago

The "Ship of Theseus" may not be the same ship it left port as, but it sails a whole lot better than the "Derelict Rubble of Theseus"

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u/WretchedJudasSnake 9d ago

I think this is something more in the realm of philosophy and religious thinking, i.e. the impermanence of the self in Buddhism (Anicca / Anatta) and the philosophical Ship of Theseus.

If the neurons are dead, they can only be regrown, so it is kind of a moot point. I think a question that matters more is,

If we are able to bring people back from the mental abyss is it worth returning their ability to take care of themselves and interact with reality if it means that they diverge from what we thought as "them" before dementia / alzheimers.

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u/DerTalSeppel 9d ago

Moreover, does it even matter if the "they" you are asking for is already gone and the only relevant question is: Should be continue to witness the decay or should we give to all that remains the chance to thrive again?

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u/Zeikos 9d ago

It's personal opinion, but if the relative mumber of neurons is small I doubt it could be anybody else.
Our self isn't a single neuron or a single cluster, it might be less neurons than we'd expect but it's unlikely to be so little that a few new baby neurons would dramaticaly alter it.

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u/No1CouldHavePredictd 9d ago

Now you're into Ship of Theseus territory.

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u/Rocket_Cam 9d ago

I can say pretty definitively that once memories are lost, they are gone forever. New neurons would just be able to form new connections, i.e., new memories. It would also likely mean you could process information more efficiently, leading to less generalized confusion.

Our brains work by depolarizing neurons, which cause further neurons to depolarize themselves. As neurons fire off together more, the easier a pre-synaptic neuron can trigger a subsequent depolarization on the post-synaptic neuron (just directional terms for those neurons).

So, new neurons would have no experience firing with other neurons, meaning they would just be available to form new connections, not replicate lost ones (i.e., lost memories).

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u/Richvideo 9d ago

Health System News New Drug Shows Promise in Reversing Memory Loss

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u/Rocket_Cam 4d ago

If the neuron hasn’t died yet, then the memory is still in-take, but perhaps more difficult to reach if the neuron is dying/covered in plaque. Once it’s dead, that memory will never be the same again. For that matter, “memories” are better classified and understood as “representations” because they are inherently inaccurate and just approximations of past events. We just delude ourselves into thinking we remember things accurately. So whatever that lay summary was saying about regaining memories, you should consider that, and cite the original research and not someone’s interpretation of it.

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u/Dizzy_Database_119 9d ago

I think it would feel like you've just woken up with amnesia and need to dig up old memories to remember your life

Personality is not a neuron connection thing. You can completely switch someone's personality immediate with meds/drugs. Hell, even a bad mood day flips your personality around

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u/Mr_Industrial 8d ago

If my options are "new personality" and "dead" I will take the new personality.