"Instead, iPSCs are taken from adult human cells, usually from a skin or blood sample, and converted into an embryonic-like state."
What would happen if the adult human donor took these embryonic-like cells and reinjected them? Would the person develop the vim and vigor of a young adult?
For anyone who wants to see the answer without looking at the, uhh, medical images, here's a quote:
"Pluripotent stem cells including human induced pluripotent stem cells have a unique property of being able to generate teratomas when injected in rodents in the research laboratory.[62] For this reason, the so-called "teratoma assay" is one of the gold-standard validation assays for pluripotent stem cells.[63] Because differentiated human pluripotent stem cells are being developed as the basis for numerous regenerative medicine therapies, there is concern that residual undifferentiated stem cells could lead to teratoma formation in injected patients, and researchers are working to develop methods to address this concern.[64]"
Unless it is from a biological clone of you (or iPSC) and pre-treated with a chemical cocktail and used under carefully controlled conditions. This isn't the 1960s, we have a much better grasp of molecular biology and human development now. The fields of immunology and regenerative medicine have come a long way.
When you think about what the genome encodes, you have to appreciate the finely tuned timing and signalling of developmental biology. As development progresses, cell populations split off and take on different forms, functions, biochemistry, and gene regulation to fit their new purpose.
Our bodies differentiate cells into different lineages precisely when it is developmentally necessary. You don't want to turn the clock in reverse. That's a disease state and a hallmark of cancer.
>> You don't want to turn the clock in reverse. That's a disease state and a hallmark of cancer.
Well, you actually do want to turn the clock in reverse. That's a hallmark of the highest so far methodology standard in science: if you want to position that you gained a full understanding of an object, you need to be able to reverse engineer it both in space and time.
Many cancers contain senescence associated secretory phenotype (SASP) and senolytic drugs have been researched to be able to neutralize cancer cells as well as senescent cells.
You do want to turn the clock in reverse, only maybe not the whole way back to the embryonic state, but a couple of formal years or decades back to reset the epigenome, and this is exactly what David Sinclair, Vittorio Sebastiano and many others are undertaking now.
“That's a hallmark of the highest so far methodology standard in science: if you want to position that you gained a full understanding of an object, you need to be able to reverse engineer it both in space and time.”
We can’t even do this with simple black box game playing AIs, so a new paradigm may be needed.
Oh, with AI game players, can't you just insert a print statement in code to simultaneously log all weights' changes and their accompanying changes in performance etc in a file and get another AI like some multi-parameter regression to search for correlations in it?
consciousness then evolves into telepathy..the scientists while hard at work studying these growing cell masses then start hallucinating while in the presence of the mini brains, driving them into insanity.. and next thing you know we've gone full on Akira and the destruction of neo Tokyo is imminent
Is it possible to write a story from the perspective of the brain? Would the first few pages or even the first chapter just be blank or would it be nonsensical noise?
Would it even make sense to use words? Maybe a visual/interactive medium like a game would make more sense.
On that note, what does somebody who was born blind perceive? Do they perceive blackness or is there no sense of sight at all?
Boltzmann Brains don't fluctuate into existence, they get created when entropy is moderate enough to produce galaxies with people in them that develop tech for cloning.
Probably some of scale - while body and brain size map together well enough that tanners knew that any creature had enough brains to tan their hide there are limits to how small a viable brain may be. Second would be exposure towards some sort of input to respond to.
One may hope so, though even nature has never shown itself to be kind about things, merely expedient.
Just as when the discussion is about AI, it is my sad belief that we as a species do not have a single concept of consciousness sufficient to even be tested for, merely a collection of vague ideas that at best refer to each other and at worst to nothing at all.
Two eyes give a very very significant increase in information provided over one eye, because two eyes is absolute minimum for depth perception. Three eyes and more don't provide any significant advantage functionally, except maybe redundancy.
Two eyes are necessary for stereoscopic depth perception, but perception of depth can be had with a single eye adjusting its focal length, using context clues, or moving your head around to acquire depth information from motion parallax.
as an example of a context clue, when driving you tend to use the size of a car as a proxy for its distance, instead of stereo vision depth perception. It's fairly common for people to lose acuity in one eye but can still drive for this reason.
The smaller peripheral eyes of spiders seem to be smaller and simpler then two (or four) "main" eyes. Processing data from more eyes requires more of the expensive brain tissue.
Your reasoning about bilateral/symmetry implies there is an even number of things (like the 8 eyes spiders have) 2 is not the only even number for this.
(Also, I find it interesting that most of internal organs are not symmetrical)
Eh, similar answer, your basic body plan goes back really far in your genetic history and is a really early part of embryonic development. All of your relatives going back to a common ancestor ~500Ma have two eyes. It’s a quick internet answer not an essay, the exact correct common ancestor / taxonomy group is a bit difficult to pin down.
Bilateria is the reason the number is even… some common ancestor after you split with spiders is the “exactly two” reason, which i think is all vertebrates now, or at least close to that level.
'External symmetry is an adaption to environment' seems to be a promising starting point. You can see this at the micro level too: cell externals and internals.
If we're going to be pedantic, all people have two eyes, some are just not functional. If you mean losing the organ entirely, this usually happens after birth.
Light provides predictive power to an organism. That is, light can provide information about action at a distance, of relevance to the future, if there is a brain to process it.
Neurons connect and disconnect via hebbian and anti-hebbian processes in response to the stimulus, so in a way the impact of light energy is structured within a biological substrate.
At some point we may end up with a brain(s) used to control the metaverse? Tad Williams Otherland series felt ridiculous toward the end, now I'm not so sure.
I honestly still think this is the real plot of the Matrix. They weren't batteries - they were cheap computing resources working in concert to literally create the Matrix.
Apparently that's what they intended originally. They wanted Morpheus to show a CPU instead of a battery to Neo in that scene. But they decided to not do that, because they thought that the audience would not understand what that is.
I don't know about controlling the metaverse, but my personal theory is that AI will be dominated by computer-integrated primate brains, possibly genetically modified.
Isn't this expected? Synthesizing a fully functional "organoid" from stem cells is profound, but why are eyes more important than the rest of the brain? What's surprising?
My take from reading the article is that they were able to make a cerebral organoid develop these eye cups. Until now they were either able to make a brain or the eye.
> In previous studies, only pure retinal cells or optic cups were grown in the lab individually. Jay Gopalakrishnan, an organoid expert at University Hospital Düsseldorf, and his colleagues used iPSC-grown mini brains to see if eye structures could develop as an integrated part of the organoid—instead of growing the two parts separately, Science Alert reports.
Having graduated from high school, this isn't surprising to me. Why would it be? So I'm left to wonder what's going on with this story. Either Smithsonian magazine is read by people to whom basic biology is a mystery, or the editors think that's the case. Or, perhaps Smithsonian magazine is read by people who like this kind of gory horror porn (or the editors think that's the case).
What would happen if the adult human donor took these embryonic-like cells and reinjected them? Would the person develop the vim and vigor of a young adult?