Back

Human brain is two separate organs, Stanford Medicine-led research finds

95 points1 hourmed.stanford.edu
itvision24 minutes ago

What a way to oversell the discovery.

The reality is:

    * Different brain regions have different functions: ancient knowledge.
    * Different regions contain distinct cell types and molecular programs: also well established.
    * Anterior and posterior brain structures may trace back to fundamentally separate progenitor lineages that were independently specified very early in evolution and development: that's the interesting new result.
The headline should have been: "Human forebrain and hindbrain arise from distinct embryonic progenitor lineages" - not that we have "two organs" in the brain.
lucideer5 minutes ago

Given the parallel example cited in the article of jellyfish having two spatially separate organs, & the subsequent speculation that our own ancestors could also have had spacially separate anterior & posterior masses, the title doesn't really seem unreasonable in its hyperbole.

While it might not be perfectly accurate it's hardly misleading.

sandeepkd17 minutes ago

Though I agree with the detailed differentiation, still for the headline purpose a generic one that resonates with people easily isn't a bad choice

t-writescode19 minutes ago

I mean, I learned a bunch of neat new stuff, so I’m excited!

bethekind57 minutes ago

> They identified two different brain progenitor cells. One, which expresses a gene called Otx2, is destined to become the forebrain and midbrain. The other, which expresses a gene called Gbx2, is committed to forming the hindbrain. They showed that these two cell populations never overlap; they are mutually exclusive from the earliest stages of development.

Very cool. Never thought the brain could have two completely different ancestors

kazinator25 minutes ago

Fun fact: the hindbrain progenitor cell is shaped like a little lizard.

trhway29 minutes ago

and from another post on the front page right now https://news.ycombinator.com/item?id=49735541 :

"Nervous systems are typically defined as networks of neurons that communicate across synapses. But Burkhardt’s lab found something unique in ctenophores: Beneath the animal’s outer surface is a nerve net (pink mesh in this 3D reconstruction) whose neurons are connected by continuous cytoplasm — but with no synapses between them. “I don’t think any other animal has a nervous system like that,” Burkhardt said. Because ctenophores are one of the earliest branches of the animal family tree, the finding indicates that evolution may have crafted nervous systems twice: in ctenophores, and separately in jellyfish and all other animals."

celadonuproot5 minutes ago

And that's why we oftentimes talk about "brains" in the plural

k3101 hour ago

bioRxiv preprint July 2025 [0]

The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license.

[0] https://www.biorxiv.org/content/10.1101/2025.07.02.662771v2

PDF is free to download.

johnnienaked6 minutes ago

A bicameral mind cool

softgrow46 minutes ago

We are going to have to deprecate an idiom or two. "I'm in two minds about something" now gives the wrong meaning.

readthenotes145 minutes ago

Not to mention the gut brain-- That's the organ I blame for the ice cream I just ate

patates38 minutes ago

The best way to stop eating ice cream is to stop buying ice cream. If it's in the freezer, it'll be eaten.

polotics10 minutes ago

I think there is a better way: The colder something is, the less sweet it will taste. if you warm-up ice cream and taste how sickeningly sweet that soup is, you won't be having so much for a while...

proc040 minutes ago

I can see how one of these is the gut feelings origin, and other bodily feelings.

drabbiticus8 minutes ago

It's cool, but the headline is really pretty misleading.

The new result seems to be that researchers have identified different progenitors for fore/midbrain vs. hindbrain and have found that they can be identified by some specific developmental gene markers. That's genuinely cool.

However, organs are not typically defined by a single tissue characterized by a progenitor that can be labeled with a single gene marker. I suppose it's fine if on a functional and anatomical level you want to split the fore/midbrain and hindbrain into two different "organs", but whether you think of the brain as 1 organ or 2, it really doesn't change much in terms of how you would think about these regions.

It isn't at all surprising that different regions of the brain have localized functions; some of the earliest evidence of this was how focal injuries (like strokes) have characteristic deficit patterns depending on brain region affected, and obviously there has been a lot of work since then further showing the organization, function and development of different brain regions.

geuis40 minutes ago

This isn't peer reviewed, just a press release. 10 other "papers" will be published in the next 2 weeks counterfinding anything in this post.

Science moves forward yet again with a few backward steps.

ykl10 minutes ago

Here is the peer reviewed publication in Nature Neuroscience:

https://www.nature.com/articles/s41593-026-02433-7

The press release does somewhat overhype up the actual finding though. The actual finding is that different parts of the brain arise from different neural ectoderm progenitors, which explains why it’s so hard to get a forebrain neuron to behave like a hindbrain neuron and vice versa in the lab.