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Human brain is two separate organs: A new study led by Stanford Medicine found the brain is two separate organs adjacent to one another. The finding could aid research into devastating neurological diseases.
Interesting that they distinguish “language” as a function of the forebrain and “speech” a function of the hindbrain. I wonder what the implications are.
Speech is a motor planning and coordination function involving the diaphragm, the larnyx, lips, tongue, and jaw.
Language (the association of words and grammar with meaning and the capacity for understanding and symbolic manipulation of words) is an entirely separate non-motor function.
This is so interesting, my daughter has incredible receptive language skills but very limited expressive language skills, she uses a device to communicate instead of spoken words
I'm so glad that she has access to an AAC device! So many people don't understand the difference between language ability and speech, and they worry that if they provide AAC, their child will "never learn to talk", not understanding that speech and language are really separate, and using language through an AAC actively builds expressive language skills, and withholding the means for effective communication stunts language development. The motor skills for speech are a whole different thing.
Yes when we do speech therapy our primary goal for her is to boost her communication skills no matter what they might look like, I still cried tears of joy when she used the aac to say I love you for the first time, it didn't need to be words
Interestingly language comprehension and grammar are also very highly localized and only in one hemisphere of the brain. There's also two distinct regions one for understanding and comprehending speech and the other for then formulating a response choosing the correct words etc.
There are specific kinds of aphasia where Broca's area is damaged in which patients still understand speech and text, still think they are able to express themselves clearly (i.e. before diagnosis its hard, and extremely frustrating for them!, to understand why no one can understand what they're trying to say), but what actually comes out is unintelligible gobbledegook using totally the wrong words and phrases etc.
You're thinking Wernicke aphasia (caused by damage to Wernickes area) which is a fluent aphasia, where someone speaks with the fluency and cadence of normal speech, but is speaking complete gibberish. Broca aphasia (caused by damage to Broca aphasia) is nonfluent, as in, words dont come out easily, and speaking is effortful. I have Broca aphasia during seizures and at least in my experience it sounds very much like forgetting what you were saying in the middle of saying it. "Oh, well I don't, uh..... I,uh........... um,.............. ....... ..... I, uh,... ....... .... I d ....... don't......... ......" and then after the seizure is over i will sometimes literally open my mouth and nothing will come out. No sound. I'll get visibly frustrated because I'm trying to speak to someone and just cannot for some reason.
I think there's an aphasia society that has additional details and examples of different types of aphasia, but i can't remember offhand what it's called.
This happens to me when I’m nervous. I am fully aware that the person is speaking but I have no idea what they’re saying. However reading and writing remain fine.
I haven’t paid attention to anything like that, but I’ve also been struggling to get back to a relatively normal life. Was basically bed-bound about a year ago, but spent some time at the Shepherd Center in Atlanta, and they helped with a lot of my gross motor function.
I have a slower processing speed and say “what?” because I heard it fine, but it didn’t compute yet. Often it becomes clear to me as soon as they start to repeat themselves. People think it’s a hearing issue. It’s not.
I just need a few more seconds than what is average. Especially if what is said to me is random (off topic).)
Motor neurons in the spinal cord enable conscious movements of your muscles. The hindbrain is at the “nose end” of the spinal cord, so it’s not too surprising that motor neurons from the hindbrain enable the conscious movements of your facial muscles required for speech. I think this is all they are trying to say about the involvement of the hindbrain in speech. (Understanding and planning speech is a function of the cortex.)
People unable to speak, can still swear, and the Mythbusters proved that swearing, even fake swear words, increases your pain tolerance. I'd guess a relation or connection.
Oh that is so cool! I saw this documentary where the person couldn’t speak but worked up to pointing to letters to spell words. She wrote long, detailed, emotional, and intelligent essays.
They described her mind being trapped in her body and not being able to get the words out.
That makes sense. AI cracked coherent text fairly quickly but the coherence was only word to word. It took several more years before language fluency appeared.
This is how you get people speaking nonsense sentences during strokes or other severe cerebral events.
Speech is verbal language, language is the collections of sounds and symbols we use to represent concepts. There are many languages and many types of languages and they dont all need speech or sounds or visual elements. Speech involves motor functions and stuff. Thats why they are two very distinct things in tue brain.
This is how we write conversational AI bots today as well. Cascade architecture separates audio processing into a pipeline of stages. Audio flows in, gets analyzed for turn taking, transcription, and sentiment and then is fed into a reasoning layer. The reasoning layer spits back a bunch of text which then goes into a coordinator that keeps track of who is taking turns speaking, gets synthesized back into audio, and then the coordinator figures out how to drop it or play it out.
It’s interesting because these relationships mirror the way this article frames the brain. The layer handling reasoning and interpretation are separate from the thing doing the speaking.
Not specifically from two different progenitor cells, afaik. There are multiple models describing two brains though. Sometimes the two different hemispheres are seen that way based on injuries that could happen to either side or the network that connects them. Arguably, since some people have lived with only a brain stem intact, everything else can be seen as secondary. There used to be a thinker/prover two-brain model but that wasn’t based on biology.
Starting to wonder if we are the "human" equivalent of the Siphonophore.
We seem to be various different things working together quite well. Everything talks generally but some upset in the gut messes with our mood for example. Everything ties into something else in unexpected ways.
I agree. In my opinion, the brain is more than 2 organs, I think it's a half dozen or more different parts that spent a billion years learning to work together. And when one or two have a bad day, the whole organism has a harder time operating.
I can't argue with that, no matter what part of my brain I use.
Obviously you can't prove it's wrong and as someone earlier who said you are wrong I'm not sure why they'd discount it so readily.
We are a mash up of billions or even trillions of viruses and bacteria that have adapted and homogenised over a millennia of generations. This started long before we walked on two legs and probably won't stop until we destroy ourselves.
So why wouldn't the brain be a load of different ideas working together? We know about the primal reptile brain. We know about the left and right hemispheres, hippocampus, thalamus etc. so yeah we have multiple drivers in every sense of the word.
I'm a mix of two different people and that shows. Exponential mixing is on show.
Well, the left and right hemispheres of the brain are connected to each other by the corpus colossum which is essentially a big bundle of nerves. Without it, the hemispheres wouldn’t be able to talk to each other. It’s really important.
With that in mind, nerves live everywhere else in our bodies, right? If all of those nerves connect to the brain, I think it must mean that they also connect to each other. Like the hemispheres. But in a more dispersed sense, not all in the exact same place like with the corpus colossum.
Also the brain has to fit entirely into a tiny protective space while the rest of the nerves in our bodies have free range to expand outward.
I think everything is probably connected in ways we won’t understand until we better understand the nervous system as a whole… which is probably like me saying,
“Yeah, we’ll understand culture better once we understand human nature.”
In its entirety? Humanity was not even set up to be centralized to one place. We live and grow and thrive and create and destroy things, everywhere we expand to. As we learn more and grow more, we get better and better at this. But we don’t get more unified. Not yet, anyway.
Okay, I’m rambling. I don’t have any idea about how things really work, I just have a lot of questions without answers.
"Two parallel neural ectoderm progenitors contribute to the developing brain"
"we postulate the brain is a composite organ emanating from two lineage-restricted progenitors"
The heart is also formed from two separate lineage cardiac progenitor cells that combine to form a single organ. so unless you want to consider the heart 2 organs as well, the logic for this headline does not hold.
TLDR: Stanford researchers found the brain is not one organ but two. One runs your breathing and heartbeat. The other lets you do math and write poetry. They evolved separately and just got packed together. This could finally help us study ALS and other brain stem diseases.
We have all been taught the brain is one single organ. New Stanford Medicine research says nope. It is actually two separate organs that evolved independently over hundreds of millions of years.
Here is the deal. Your forebrain handles the fancy stuff like language, consciousness, and abstract thinking. Your hindbrain, aka the brain stem, runs the autopilot stuff like breathing, sleep, and heartbeat.
Scientists used to think one single cell early in development made the whole brain. This new study shows the front and back come from completely different cells that never mix. One becomes the forebrain. The other becomes the hindbrain. They are basically on parallel tracks from day one.
This explains why scientists spent decades failing to grow hindbrain neurons in a lab. They were trying to turn forebrain cells into something they physically cannot become.
Now the team actually grew working human hindbrain neurons in a dish for the first time. These neurons fired electrical signals and made the right proteins for facial and swallowing muscles.
They also looked back 550 million years and found the same two origin pattern in chickens, zebrafish, and even acorn worms. Jellyfish, which split from us 600 to 700 million years ago, have two nervous systems at opposite ends of their body.
This matters because it could unlock research into ALS, spinal muscular atrophy, and other diseases that destroy the brain stem. Scientists could never get brain stem tissue from living patients before. Now they can grow it. There is even a weird link to weight loss drugs like semaglutide since the hindbrain controls hunger.
The study was published in Nature Neuroscience on Sept 18. Kyle Loh is the senior author. Carolyn Dundes and Rayyan Jokhai are co first authors.
Next up the team wants to figure out where the spinal cord comes from and exactly how ALS and SMA break hindbrain neurons.
This isn't about the two halves of the cerebrum, though. Both of them arise from the same progenitor cell line. This is about the cerebrum and related structures vs. the cerebellum and related structures.
Yeah I was thinking that too, it makes sense of a lot of things where they sever the corpus callosum and all sorts of cool effects ensue.
Also occasionally they give kids with extremely severe epilepsy a hemispherectomy where they remove one entire side of the brain and the person can still function.
Why do you think that? The article goes into detail about why they think it's two - there are two separate embryonic progenitor cells that produce the cell lineages in the brain. One lineage can't substitute for the other, making them distinct. It's not an arbitrary number.
I’m not who you asked but I did just get done reading the article, which divides the brain into two organs based on progenitor cells. I have nothing to argue against that but I can try to answer why someone might think there’s perhaps four or more. Basically, why stop at two?
It’s been twenty years since I’ve seen the inside of a neuropsych textbook but I recall the argument that the brain could be divided into separate yet intertwined organs based on their behavior and nerve structure. We’d have the brain stem, then the big structures surrounding it: The cerebellum, and broadly, the cerebrum which is in two hemispheres. All four structures can be subdivided and have their own macro and microscopic distinctive features. People have lived having hemispheres or cerebellum removed (I’m skipping over what it’s like to live without a cerebellum here) so the old school conclusion was that these were separate organs. If you really want to make things messy, where do we put eyes and the spinal cord? The optic nerves are specialized nerves going directly to the brain, if you can see the back of someone’s eye you’re looking at something directly attached to the brain and could even consider it part of the brain itself. The nerves in the spinal cord aren’t all that different from the brain stem compared to other parts of the brain, so where do we draw the line on what’s actually the brain? If we consider the optic nerves and spinal cord as parts of the brain, what about all the other nerves in our body? I think of the brain as having multiple organs and not being entirely contained in the skull. But I also think none of that necessarily contradicts there being two brains since neurological systems and classifications are overlapping. If anything, I think the article validates the multiple brain model.
I've always felt there was a distinct separation between the brain and the "mind", and that I (the self) has to act as mediator and translator between the two.
Surprise surprise, hyperbole in science headlines. Calling the brain two separate organs is hyperbole, or dramatic interpretation at best. The study suggests that the brain develops from two separate, simultaneously emerging cell lineages, which is groundbreaking and can lead to new understandings and treatments but… SMH at that headline.
I have noticed that the more basic (and therefore older) the part of the brain, the more control it has, and the more difficult it is to control with the "forebrain". For example, controlling your heart beat or digestive system is nearly impossible, if not completely impossible. And controlling your emotions, which are a newer, but still very old part of the brain, is very hard, yet possible.
I have always been curious what it would take to engineer the "forebrain" to have primary control of all of the other parts of the brain. I am also very interested in extending forebrain neurons throughout the body so that cognitive ability can be greatly increased, without needlessly increasing the size of the cranium.
We can lower our heart rate by doing mindfulness exercises etc. The integration between the brains are quite deep. And that isn't even taking the gut into account.
This finding is nothing short of a revolution in how we understand the brain.
by neurological diseases you guys mean alzheimers and not something very controversial that lots of people (including me) want to keep like autism, right?
Wonder if this is a path to uploading consciousness some day. The problem has been any uploaded conciousness would not be “you”. You’d lose your stream of consciousness and would cease to exist. If instead you replaced/uploaded one hemisphere at a time, you could maintain an unbroken stream of consciousness
No one has successfully mapped out where exactly the "you" of a person exists. There's evidence that different mental functions involved areas all over the brain. Nothing that makes us human can be neatly bisected in one hemisphere or the other. We are discovering that people can function and be a "self" even when large areas of the brain are destroyed but doing a Frankenstein with people's minds and have them remain human or have a self is still impossible. I had a boyfriend in college studying a field in computer science; he was totally obsessed with making this a reality. 30 years later I haven't heard that we are any closer to it. It's still only science fiction. (Philip K. Dick wrote some amazing scifi on the subject if anyone's interested)
Otarmichael | 16 hours ago
Interesting that they distinguish “language” as a function of the forebrain and “speech” a function of the hindbrain. I wonder what the implications are.
Edit: wow, so cool to see all these responses!
aculady | 15 hours ago
Speech is a motor planning and coordination function involving the diaphragm, the larnyx, lips, tongue, and jaw.
Language (the association of words and grammar with meaning and the capacity for understanding and symbolic manipulation of words) is an entirely separate non-motor function.
kaitabong | 11 hours ago
This is so interesting, my daughter has incredible receptive language skills but very limited expressive language skills, she uses a device to communicate instead of spoken words
aculady | 11 hours ago
I'm so glad that she has access to an AAC device! So many people don't understand the difference between language ability and speech, and they worry that if they provide AAC, their child will "never learn to talk", not understanding that speech and language are really separate, and using language through an AAC actively builds expressive language skills, and withholding the means for effective communication stunts language development. The motor skills for speech are a whole different thing.
kaitabong | 11 hours ago
Yes when we do speech therapy our primary goal for her is to boost her communication skills no matter what they might look like, I still cried tears of joy when she used the aac to say I love you for the first time, it didn't need to be words
aculady | 11 hours ago
Of course you cried for joy! That's so beautiful. She did say words! She just used the AAC instead of her larynx.
ValuableAd7538 | 3 hours ago
My son has autism, and we use a communication board right now while he’s learning. But he’s 3.
merryman1 | 10 hours ago
Interestingly language comprehension and grammar are also very highly localized and only in one hemisphere of the brain. There's also two distinct regions one for understanding and comprehending speech and the other for then formulating a response choosing the correct words etc.
https://en.wikipedia.org/wiki/Wernicke%27s_area
https://en.wikipedia.org/wiki/Broca's_area
There are specific kinds of aphasia where Broca's area is damaged in which patients still understand speech and text, still think they are able to express themselves clearly (i.e. before diagnosis its hard, and extremely frustrating for them!, to understand why no one can understand what they're trying to say), but what actually comes out is unintelligible gobbledegook using totally the wrong words and phrases etc.
https://en.wikipedia.org/wiki/Expressive_aphasia
BassBottles | 6 hours ago
You're thinking Wernicke aphasia (caused by damage to Wernickes area) which is a fluent aphasia, where someone speaks with the fluency and cadence of normal speech, but is speaking complete gibberish. Broca aphasia (caused by damage to Broca aphasia) is nonfluent, as in, words dont come out easily, and speaking is effortful. I have Broca aphasia during seizures and at least in my experience it sounds very much like forgetting what you were saying in the middle of saying it. "Oh, well I don't, uh..... I,uh........... um,.............. ....... ..... I, uh,... ....... .... I d ....... don't......... ......" and then after the seizure is over i will sometimes literally open my mouth and nothing will come out. No sound. I'll get visibly frustrated because I'm trying to speak to someone and just cannot for some reason.
I think there's an aphasia society that has additional details and examples of different types of aphasia, but i can't remember offhand what it's called.
donthate_individuate | 7 hours ago
Cool, very interesting. I feel like I learn things really easily, but I sound dumb if I try to explain anything I’ve learned to anyone else
Secure-Pain-9735 | 15 hours ago
You oughta see how many ways you can be deaf or blind.
For instance, people with Wernicke’s encephalopathy will have difficulty understanding language audibly. It can present like they are hard of hearing.
“What?”
You speak louder, they get mad.
“I’M NOT DEAF!”
They can hear fine, they just can’t process language as well.
But, if you write something down they can read it and understand it fine.
So language is processed in several areas in different ways.
Sufficient-Guava-152 | 13 hours ago
This happens to me when I’m nervous. I am fully aware that the person is speaking but I have no idea what they’re saying. However reading and writing remain fine.
Secure-Pain-9735 | 13 hours ago
I have it a bit as well secondary to my ADHD. The Wernicke’s is a tad different, though. It’s constant when that area is damaged.
FriendorFo | 12 hours ago
I’ve had several TBIs, and struggle with this exact same issue.
Talking to me? 70/30 shot I comprehend everything. I’m able to read it? Usually fine.
Secure-Pain-9735 | 11 hours ago
Any noted increase in detail perception and/or creativity?
Wernicke’s predominately develops on the left hemisphere, and left hemisphere damage usually correlates with instances of acquired savantism.
FriendorFo | 11 hours ago
I haven’t paid attention to anything like that, but I’ve also been struggling to get back to a relatively normal life. Was basically bed-bound about a year ago, but spent some time at the Shepherd Center in Atlanta, and they helped with a lot of my gross motor function.
EclecticEthic | 5 hours ago
I have a slower processing speed and say “what?” because I heard it fine, but it didn’t compute yet. Often it becomes clear to me as soon as they start to repeat themselves. People think it’s a hearing issue. It’s not.
I just need a few more seconds than what is average. Especially if what is said to me is random (off topic).)
Secure-Pain-9735 | 4 hours ago
Common in ADHD.
WaterBearDontMind | 15 hours ago
Motor neurons in the spinal cord enable conscious movements of your muscles. The hindbrain is at the “nose end” of the spinal cord, so it’s not too surprising that motor neurons from the hindbrain enable the conscious movements of your facial muscles required for speech. I think this is all they are trying to say about the involvement of the hindbrain in speech. (Understanding and planning speech is a function of the cortex.)
Darklumiere | 15 hours ago
People unable to speak, can still swear, and the Mythbusters proved that swearing, even fake swear words, increases your pain tolerance. I'd guess a relation or connection.
No_Warning8534 | 14 hours ago
This is why fuck is my favorite word 🥰🙃
It's science.
P0lyphony | 13 hours ago
I wonder if swearing makes sex better too.
Bearded_Toast | 13 hours ago
Fuck no it doesn’t :(
StynaSilverwing | 15 hours ago
Oh that is so cool! I saw this documentary where the person couldn’t speak but worked up to pointing to letters to spell words. She wrote long, detailed, emotional, and intelligent essays.
They described her mind being trapped in her body and not being able to get the words out.
UnusualBarnstormer | 14 hours ago
That sounds devastatingly horrible.
RegressToTheMean | 14 hours ago
Johnny's got his gun...
UnusualBarnstormer | 13 hours ago
Yikes
Something_Clever919 | 12 hours ago
What’s it called?
DeathToAmerica2026 | 9 hours ago
That makes sense. AI cracked coherent text fairly quickly but the coherence was only word to word. It took several more years before language fluency appeared.
This is how you get people speaking nonsense sentences during strokes or other severe cerebral events.
antsh | 6 hours ago
In my head, I can roll Spanish R’s like Sofia Vergara. Using my tongue, though? No way.
I imagine it’s basically like that, right?
The_Weekend_Baker | 15 hours ago
Sign language vs. spoken language maybe?
MuchWow81 | 15 hours ago
Speech is verbal language, language is the collections of sounds and symbols we use to represent concepts. There are many languages and many types of languages and they dont all need speech or sounds or visual elements. Speech involves motor functions and stuff. Thats why they are two very distinct things in tue brain.
Unsounded | 10 hours ago
This is how we write conversational AI bots today as well. Cascade architecture separates audio processing into a pipeline of stages. Audio flows in, gets analyzed for turn taking, transcription, and sentiment and then is fed into a reasoning layer. The reasoning layer spits back a bunch of text which then goes into a coordinator that keeps track of who is taking turns speaking, gets synthesized back into audio, and then the coordinator figures out how to drop it or play it out.
It’s interesting because these relationships mirror the way this article frames the brain. The layer handling reasoning and interpretation are separate from the thing doing the speaking.
404_Username_Glitch | 15 hours ago
The brains like "Holy fuck, im TWO brains?"
DocJawbone | 15 hours ago
I'm seein' double here - four brains!
Evening_Ticket7638 | 14 hours ago
Here i thought im the only one who still uses that reference to this day.
insite | 13 hours ago
That's what the forebrain thinks. The hindbrain can only motion that it already figured that out. lol
ExtremaDesigns | 16 hours ago
Sounds very positive for understanding the brain.
FaceDeer | 15 hours ago
Understanding the brains, plural. :)
jsmith_92 | 15 hours ago
TIL the brain is two separate organs
hansolo-ist | 15 hours ago
My brain trying to identify as two organs
ArmpitNoise | 14 hours ago
Mine is more akin to a precussion instrument.
jsmith_92 | 14 hours ago
Prefers being slammed like nightstand drawer that won’t stay closed?
meschidied | 9 hours ago
I should call her
drkuz | 14 hours ago
Insert dirty joke about two organs
P0lyphony | 13 hours ago
Insert tangential reference to music written for prepared piano.
VerilyShelly | 12 hours ago
I certainly feel like some random objects are jammed in my wires sometimes.
P0lyphony | 11 hours ago
John Cage would call us music.
meschidied | 9 hours ago
What... Is the music... Of life...
P0lyphony | 8 hours ago
If only I had four minutes and thirty-three seconds exactly to explain it to you…
daou0782 | 10 hours ago
Source?
jsmith_92 | 10 hours ago
https://www.reddit.com/r/neurobiology/s/vqEL1ngYUg
CosmicToaster | 15 hours ago
Didn’t we already know this though?
yogo | 13 hours ago
Not specifically from two different progenitor cells, afaik. There are multiple models describing two brains though. Sometimes the two different hemispheres are seen that way based on injuries that could happen to either side or the network that connects them. Arguably, since some people have lived with only a brain stem intact, everything else can be seen as secondary. There used to be a thinker/prover two-brain model but that wasn’t based on biology.
EEZC | 14 hours ago
We thought they were different departments of a single organ, not 2 separate organs evolved to work together seamlessly.
Twitchmonky | 14 hours ago
Are you thinking about the left and right hemispheres of the brain instead?
mekese2000 | 15 hours ago
No wonder I can never make a decision.
Bignizzle656 | 16 hours ago
Starting to wonder if we are the "human" equivalent of the Siphonophore.
We seem to be various different things working together quite well. Everything talks generally but some upset in the gut messes with our mood for example. Everything ties into something else in unexpected ways.
abielle1177 | 15 hours ago
I agree. In my opinion, the brain is more than 2 organs, I think it's a half dozen or more different parts that spent a billion years learning to work together. And when one or two have a bad day, the whole organism has a harder time operating.
Bignizzle656 | 15 hours ago
I can't argue with that, no matter what part of my brain I use.
Obviously you can't prove it's wrong and as someone earlier who said you are wrong I'm not sure why they'd discount it so readily.
We are a mash up of billions or even trillions of viruses and bacteria that have adapted and homogenised over a millennia of generations. This started long before we walked on two legs and probably won't stop until we destroy ourselves.
So why wouldn't the brain be a load of different ideas working together? We know about the primal reptile brain. We know about the left and right hemispheres, hippocampus, thalamus etc. so yeah we have multiple drivers in every sense of the word.
I'm a mix of two different people and that shows. Exponential mixing is on show.
abielle1177 | 12 hours ago
I don't even think they've homogenized. I think they've adapted, but they're definitely not the same.
P0lyphony | 12 hours ago
Well, the left and right hemispheres of the brain are connected to each other by the corpus colossum which is essentially a big bundle of nerves. Without it, the hemispheres wouldn’t be able to talk to each other. It’s really important.
With that in mind, nerves live everywhere else in our bodies, right? If all of those nerves connect to the brain, I think it must mean that they also connect to each other. Like the hemispheres. But in a more dispersed sense, not all in the exact same place like with the corpus colossum.
Also the brain has to fit entirely into a tiny protective space while the rest of the nerves in our bodies have free range to expand outward.
I think everything is probably connected in ways we won’t understand until we better understand the nervous system as a whole… which is probably like me saying,
“Yeah, we’ll understand culture better once we understand human nature.”
In its entirety? Humanity was not even set up to be centralized to one place. We live and grow and thrive and create and destroy things, everywhere we expand to. As we learn more and grow more, we get better and better at this. But we don’t get more unified. Not yet, anyway.
Okay, I’m rambling. I don’t have any idea about how things really work, I just have a lot of questions without answers.
Anyway, this is really cool.
swimming_in_agates | 14 hours ago
This would have very big implications on the way we approach medicine.
Stunning_Warthog_141 | 9 hours ago
And sometimes our executive branch is acting like a child and screwing up the whole system.
SelarDorr | 12 hours ago
actual publication title
"Two parallel neural ectoderm progenitors contribute to the developing brain"
"we postulate the brain is a composite organ emanating from two lineage-restricted progenitors"
The heart is also formed from two separate lineage cardiac progenitor cells that combine to form a single organ. so unless you want to consider the heart 2 organs as well, the logic for this headline does not hold.
kiwistarbaby | 11 hours ago
Thank you for giving an example with the heart, I was wondering about this exact thing!
sludgepaddle | 16 hours ago
"I like a you and you like a me and we like a just the same"
Ambitious-Pirate-505 | 7 hours ago
TLDR: Stanford researchers found the brain is not one organ but two. One runs your breathing and heartbeat. The other lets you do math and write poetry. They evolved separately and just got packed together. This could finally help us study ALS and other brain stem diseases.
We have all been taught the brain is one single organ. New Stanford Medicine research says nope. It is actually two separate organs that evolved independently over hundreds of millions of years.
Here is the deal. Your forebrain handles the fancy stuff like language, consciousness, and abstract thinking. Your hindbrain, aka the brain stem, runs the autopilot stuff like breathing, sleep, and heartbeat.
Scientists used to think one single cell early in development made the whole brain. This new study shows the front and back come from completely different cells that never mix. One becomes the forebrain. The other becomes the hindbrain. They are basically on parallel tracks from day one.
This explains why scientists spent decades failing to grow hindbrain neurons in a lab. They were trying to turn forebrain cells into something they physically cannot become.
Now the team actually grew working human hindbrain neurons in a dish for the first time. These neurons fired electrical signals and made the right proteins for facial and swallowing muscles.
They also looked back 550 million years and found the same two origin pattern in chickens, zebrafish, and even acorn worms. Jellyfish, which split from us 600 to 700 million years ago, have two nervous systems at opposite ends of their body.
This matters because it could unlock research into ALS, spinal muscular atrophy, and other diseases that destroy the brain stem. Scientists could never get brain stem tissue from living patients before. Now they can grow it. There is even a weird link to weight loss drugs like semaglutide since the hindbrain controls hunger.
The study was published in Nature Neuroscience on Sept 18. Kyle Loh is the senior author. Carolyn Dundes and Rayyan Jokhai are co first authors. Next up the team wants to figure out where the spinal cord comes from and exactly how ALS and SMA break hindbrain neurons.
Science is the only thing that will save us all.
Whole_Vegetable_6686 | 15 hours ago
“The Man Who Mistook His Wife for a Hat” by Oliver Sacks comes to mind
ifv6 | 15 hours ago
Didn’t they already at least mostly know this from when they severed the connection? One hand literally taking something out of the other, etc.
aculady | 12 hours ago
This isn't about the two halves of the cerebrum, though. Both of them arise from the same progenitor cell line. This is about the cerebrum and related structures vs. the cerebellum and related structures.
ifv6 | 10 hours ago
Ah okie, beyond my knowledge. Thanks!
Sufficient-Guava-152 | 13 hours ago
Yeah I was thinking that too, it makes sense of a lot of things where they sever the corpus callosum and all sorts of cool effects ensue.
Also occasionally they give kids with extremely severe epilepsy a hemispherectomy where they remove one entire side of the brain and the person can still function.
plushies-and-crochet | 13 hours ago
We have our front brain and hindbrain. It's not the hemispheres.
SatisfactionFit2040 | 14 hours ago
A most people still walk around with half a brain.
0akney | 15 hours ago
We could call one brain System 1 and the other brain System 2.
WokkitUp | 12 hours ago
Steve Martin was right all along!
LookOverall | 17 hours ago
More than two, I think
FaceDeer | 16 hours ago
Why do you think that? The article goes into detail about why they think it's two - there are two separate embryonic progenitor cells that produce the cell lineages in the brain. One lineage can't substitute for the other, making them distinct. It's not an arbitrary number.
purple-pifflord | 16 hours ago
Thats Jimmy Brain, hes the guy who first discovered brains. Hes got the credentials.
yogo | 15 hours ago
I’m not who you asked but I did just get done reading the article, which divides the brain into two organs based on progenitor cells. I have nothing to argue against that but I can try to answer why someone might think there’s perhaps four or more. Basically, why stop at two?
It’s been twenty years since I’ve seen the inside of a neuropsych textbook but I recall the argument that the brain could be divided into separate yet intertwined organs based on their behavior and nerve structure. We’d have the brain stem, then the big structures surrounding it: The cerebellum, and broadly, the cerebrum which is in two hemispheres. All four structures can be subdivided and have their own macro and microscopic distinctive features. People have lived having hemispheres or cerebellum removed (I’m skipping over what it’s like to live without a cerebellum here) so the old school conclusion was that these were separate organs. If you really want to make things messy, where do we put eyes and the spinal cord? The optic nerves are specialized nerves going directly to the brain, if you can see the back of someone’s eye you’re looking at something directly attached to the brain and could even consider it part of the brain itself. The nerves in the spinal cord aren’t all that different from the brain stem compared to other parts of the brain, so where do we draw the line on what’s actually the brain? If we consider the optic nerves and spinal cord as parts of the brain, what about all the other nerves in our body? I think of the brain as having multiple organs and not being entirely contained in the skull. But I also think none of that necessarily contradicts there being two brains since neurological systems and classifications are overlapping. If anything, I think the article validates the multiple brain model.
Vicorin | 15 hours ago
I think you could argue that each region of the brain is its own organ, since they all serve different functions.
I’m not a scientist in that might’ve been a really stupid thing to say but it makes sense to my caveman brain
VerilyShelly | 14 hours ago
I've always felt there was a distinct separation between the brain and the "mind", and that I (the self) has to act as mediator and translator between the two.
th4d89 | 14 hours ago
Only two?
aflockofcrows | 14 hours ago
Didn't Steve Martin make a film about this?
Woodchuck251 | 12 hours ago
That one brain is two brains?
Helldiver_of_Mars | 12 hours ago
It's more than two.
CosmicDriftwood | 11 hours ago
Dap me up, other brain
Regdit-is-Unbearable | 8 hours ago
The bicameral mind is starting to sound marginally less crackpot
AdmirableVanilla1 | 8 hours ago
All I know about 2 brains is alien hand syndrome
uncoolcentral | 8 hours ago
Surprise surprise, hyperbole in science headlines. Calling the brain two separate organs is hyperbole, or dramatic interpretation at best. The study suggests that the brain develops from two separate, simultaneously emerging cell lineages, which is groundbreaking and can lead to new understandings and treatments but… SMH at that headline.
Ambitious-Pirate-505 | 7 hours ago
Thats why I am always fighting amongst myself.
I_lenny_face_you | 7 hours ago
Joke’s on them, my brain is all mid
Arkavari1 | 16 hours ago
Interesting, but I am not surprised.
I have noticed that the more basic (and therefore older) the part of the brain, the more control it has, and the more difficult it is to control with the "forebrain". For example, controlling your heart beat or digestive system is nearly impossible, if not completely impossible. And controlling your emotions, which are a newer, but still very old part of the brain, is very hard, yet possible.
I have always been curious what it would take to engineer the "forebrain" to have primary control of all of the other parts of the brain. I am also very interested in extending forebrain neurons throughout the body so that cognitive ability can be greatly increased, without needlessly increasing the size of the cranium.
EEZC | 14 hours ago
We can lower our heart rate by doing mindfulness exercises etc. The integration between the brains are quite deep. And that isn't even taking the gut into account.
This finding is nothing short of a revolution in how we understand the brain.
TheOnlyGaming3 | 15 hours ago
by neurological diseases you guys mean alzheimers and not something very controversial that lots of people (including me) want to keep like autism, right?
KDTK | 13 hours ago
Autism isn’t a disease.
cloudadmin | 16 hours ago
Wonder if this is a path to uploading consciousness some day. The problem has been any uploaded conciousness would not be “you”. You’d lose your stream of consciousness and would cease to exist. If instead you replaced/uploaded one hemisphere at a time, you could maintain an unbroken stream of consciousness
FaceDeer | 15 hours ago
This "problem" is, ironically, entirely in the mind. It's just an issue of semantics and philosophy.
My stream of consciousness is interrupted every night when I sleep, it doesn't bother me.
VerilyShelly | 13 hours ago
No one has successfully mapped out where exactly the "you" of a person exists. There's evidence that different mental functions involved areas all over the brain. Nothing that makes us human can be neatly bisected in one hemisphere or the other. We are discovering that people can function and be a "self" even when large areas of the brain are destroyed but doing a Frankenstein with people's minds and have them remain human or have a self is still impossible. I had a boyfriend in college studying a field in computer science; he was totally obsessed with making this a reality. 30 years later I haven't heard that we are any closer to it. It's still only science fiction. (Philip K. Dick wrote some amazing scifi on the subject if anyone's interested)