[HN Gopher] Neuronal wiring diagram of an adult brain
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       Neuronal wiring diagram of an adult brain
        
       Author : mpweiher
       Score  : 59 points
       Date   : 2023-07-02 08:07 UTC (14 hours ago)
        
 (HTM) web link (www.biorxiv.org)
 (TXT) w3m dump (www.biorxiv.org)
        
       | YeGoblynQueenne wrote:
       | Holy misleading title, batman. The linked preprint is talking
       | about an adult _fruit fly_ brain:
       | 
       | >> Here, we present the first neuronal wiring diagram of a whole
       | adult brain, containing 5x10^7 chemical synapses between ~130,000
       | neurons reconstructed from a female Drosophila melanogaster.
       | 
       | Really need some clarification, that title does.
        
       | [deleted]
        
       | wiz21c wrote:
       | In the article they say openness is really important. But when
       | you to the website, you have to use Google Account... It's open
       | yeah, but someone wants to track you on this...
        
         | ProllyInfamous wrote:
         | I was able to legally download the entire research PDF directly
         | from the linked-to-URL -- without logging in [and I do not have
         | any Alphabet accounts, with DNS-block].
        
         | ggm wrote:
         | Being tracked is different, and does not negate openly
         | available. You don't get into every library in the world simply
         | by turning up: identity has been a part of access since writing
         | was invented. You can't request books from many libraries
         | without identifying yourself and the works requested.
        
           | Genghis_Khan wrote:
           | In most libraries in the US, browsing the collection--even
           | taking books from the shelves to a table for a while to read
           | and make notes--does not require any sort of identification
           | whatsoever. It's only when we temporarily deprive the library
           | of a copy of a work, i.e., borrow it, that we have to
           | identify ourselves.
        
             | jakear wrote:
             | In public libraries sure, but not in many academic
             | libraries or other private ones. Which is of course where
             | the more interesting (not mass-produced) content is held.
        
               | tgv wrote:
               | And nobody would call those open.
        
           | kwhitefoot wrote:
           | On the contrary in every library I have been to you just walk
           | in and browse the books. Last time I went to a university
           | library a librarian was more than willing to help me find the
           | books I needed and didn't ask any questions at all regarding
           | my identity. I dare say that she would have refused to let me
           | walk out with the books but that's understandable and anyway
           | I wanted to refer to them not take them away.
        
           | boesboes wrote:
           | That's not quite the same. I'm not required to make an
           | account with Google to go to the library. Being registered by
           | a government agency and being tracked by multi-national that
           | is famous for abusing tracking data are on a different planet
           | imo.
           | 
           | The problem, for me at least, is that I do not use google
           | products. I do not have an account and do not want one. So
           | for me, this is not openly available. We could argue about
           | the merits of being so principled in not using google, but
           | that seems besides the point :) I should be free to no do
           | business with Google and if that precludes me from accessing
           | something, it is not openly available I'd say
        
       | jmptable wrote:
       | Also of interest is the paper, "A leaky integrate-and-fire
       | computational model based on the connectome of the entire adult
       | Drosophila brain reveals insights into sensorimotor processing",
       | which discusses the results of simulations of this dataset with
       | the Brian2 spiking neural net simulator. They activate the same
       | input neurons in the simulator and real flies and show that there
       | is similar downstream behavior in the sim and real neural
       | circuits.
        
       | dpflan wrote:
       | The lead author of the paper, Sven Dorkenwald, shared more
       | resources on Twitter. Here are excerpts:
       | 
       | """
       | 
       | We are releasing a whole-brain connectome of the fruit fly,
       | including ~130k annotated neurons and tens of millions of typed
       | synapses!
       | 
       | Explore the connectome: https://codex.flywire.ai
       | 
       | Reconstruction paper:
       | https://biorxiv.org/content/10.1101/2023.06.27.546656v1
       | 
       | Annotation paper:
       | https://biorxiv.org/content/10.1101/2023.06.27.546055v1
       | 
       | There are multiple ways to access the data and the number of
       | tools is growing! https://flywire.ai/apps
       | 
       | Codex: https://codex.flywire.ai
       | 
       | CATMAID spaces: https://fafb-flywire.catmaid.org
       | http://Braincircuits.io:
       | https://braincircuits.io/app?p=fruitfly_fafb_flywire_public
       | 
       | """
       | 
       | - Original Tweet Thread:
       | https://twitter.com/sdorkenw/status/1674859033076072448
        
         | porblem wrote:
         | [dead]
        
       | comfypotato wrote:
       | Only a matter of time before this goes the way of the open worm
       | project. Incredible that they've increased the number of neurons
       | imageable by this magnitude. A similar increase from here would
       | encompass the human brain. Models of the human brain would likely
       | be indistinguishable in every way, shape, and form from the real
       | thing.
        
         | aperrien wrote:
         | Interestingly, the NeuroMechFly project [1] already exists, so
         | integrating the two together may already be under way. At 50
         | million synapses, a modest gaming PC should be able to run the
         | simulation. I wonder what people will think once they are able
         | to do this at home?
         | 
         | [1] https://prelights.biologists.com/highlights/neuromechfly-
         | a-n...
        
         | minihat wrote:
         | What will we do with a completed connectome?
         | 
         | Imagine handing a late 1800s scholar a modern processor. Give
         | him a wiring diagram, and a voltmeter. What could he learn from
         | it?
         | 
         | The connectome will be a big step, but not the penultimate one,
         | in solving human intelligence.
        
           | chrisweekly wrote:
           | "penultimate" means "next-to-last"; I'm thinking you used the
           | wrong word, or are making an obscure point I don't follow.
        
           | ecks4ndr0s wrote:
           | Maybe trying to reverse engineer it using GNNs until they
           | produce the same output(within some error margin) for various
           | arbitrary inputs? Dunno.
        
             | Retric wrote:
             | I am sure there's a great deal we can learn about how the
             | brain actually functions from such simulations.
             | 
             | However GNNs don't really capture the underlying mechanisms
             | very well. Our brains use different kinds of Neurons which
             | also use many different neural transmitters, their location
             | in 3D space matters, as do stuff like blood alcohol
             | content, O2 levels, adrenaline, signal propagation delays,
             | etc it's a stupidly complicated system even above and
             | beyond the number of neurons.
        
               | ChainOfFools wrote:
               | Also limiting it to neurons ignores all of the activity
               | and modulatuon that's increasingly being attributed to
               | astrocytes and other CNS "scaffolding"
        
         | joe_the_user wrote:
         | _Models of the human brain would likely be indistinguishable in
         | every way, shape, and form from the real thing._
         | 
         | Models that are just a map of connections certainly wouldn't
         | indistinguishable from a human brain. Every single one of the
         | trillions of human neurons is a quite complicated object.
         | Neurons communicate with each other in a number of ways and
         | neuroscience isn't even certain that communication methods have
         | been found.
        
           | comfypotato wrote:
           | This discussion is in the context of the open worm project.
           | It has successfully modeled the neurons of a nematode such
           | that the organism model functions inside a physics engine as
           | would the real organism.
           | 
           | Extending this to humans, the neuron models are good enough.
           | I've done enough biomedical engineering research in the
           | neuroscience domain to tell you: the problem is imaging the
           | connections, not modeling the neurons.
        
         | coldtea wrote:
         | > _Models of the human brain would likely be indistinguishable
         | in every way, shape, and form from the real thing._
         | 
         | Except all those pesky qualia...
        
           | ben_w wrote:
           | Can you distinguish between a system that did and a system
           | that didn't have qualia? I think that would be a major
           | breakthrough.
        
           | comfypotato wrote:
           | In the correct physics engine, with the correct models of
           | eyeballs etc., a connectome-based model may experience
           | qualia. It would likely tell us that it experienced qualia.
           | 
           | The biggest difference would be that new connections wouldn't
           | be formed, so it wouldn't learn.
        
             | coldtea wrote:
             | > _In the correct physics engine, with the correct models
             | of eyeballs etc., a connectome-based model may experience
             | qualia. It would likely tell us that it experienced
             | qualia._
             | 
             | Sure. It would say it touched water. It would just not
             | actually be wet. Which is something...
        
               | ben_w wrote:
               | When I dream of swimming, do I have the qualia of wetness
               | at the time, or does that only happen when I wake and
               | remember the dream?
               | 
               | Any neuroscientists here: does anyone know that much
               | about dreams? My memory of philosophy lessons was that
               | philosophy doesn't keep up with the latest in real
               | science...
        
               | ChainOfFools wrote:
               | but the corresponding cluster of neurons in a brain isn't
               | actually wetted by the touched water either.
        
               | coldtea wrote:
               | Yes, but it receives the input from an actual experience
               | of the body it's embodied in - from an actual wet thing.
               | As opposed to being served a simulation of the same.
               | 
               | This simulated isolated "brain" is like a heart
               | mechanically assisted to be pounding in a glass jar.
               | Sure, it's still beating, but not as part of its place
               | and environment, in a living being.
        
               | ChainOfFools wrote:
               | Where would you say experience ends, and qualia begins?
               | The way these words are being used seems to make little
               | distinction between them other than one referring to a
               | specific instance of what the other refers to in
               | generalized terms.
               | 
               | As for myself I would argue that an experience, and
               | therefore qualia, amount to an accumulated and
               | generalized succession of multiple sensory inputs
               | amalgamated by feedback and hysteresis over time, and
               | informed by the gross structure and constraints of the
               | sensory apparatus they are carried upon.
        
               | comfypotato wrote:
               | Not so different a question than asking where "synapses
               | and neurotransmitters" end and the experience of
               | consciousness begins.
        
         | ben_w wrote:
         | > Models of the human brain would likely be indistinguishable
         | in every way, shape, and form from the real thing.
         | 
         | Eventually, but the more I learn, the more I think that's going
         | to be an ethical nightmare to even test.
         | 
         | First brain to get the We Are Bob treatment is going to get
         | almost every neurotransmitter slightly wrong, and be tripping
         | as if they're suddenly alternating between ketamine/cocaine,
         | LSD/antipsychotics, and every other pair of opposite impact
         | substances you can think of.
         | 
         | I keep hearing doctors saying things like "we don't really know
         | how general anaesthetic works" and "we don't know why sleep and
         | dreams are biologically necessary, only what happens if you
         | miss them" for example, and those feel like important things to
         | understand when building models for simulation.
        
           | comfypotato wrote:
           | The neuron models used in the open worm project...
           | function...
           | 
           | That is to say that the complete organism model can learn to
           | swim, which about all the organism is supposed to be able to
           | do.
           | 
           | I see what you're saying though, that human-level function
           | will likely be much more difficult to fine-tune.
           | 
           | The ethics of it all are a philosophical wormhole.
           | Ultimately, its "consciousness" would be an image of a real
           | person. I don't think we would have to worry about it too
           | much. Saying it was truly conscious would be like saying that
           | a video of a person was conscious.
        
             | ben_w wrote:
             | > Saying it was truly conscious would be like saying that a
             | video of a person was conscious.
             | 
             | I hope we believe what's true, regardless of what that
             | happens to be -- we get bad futures either way, if we think
             | sims are conscious when they're not, or if we think they're
             | not when they are.
             | 
             | I've used the film/TV analogy myself, just over a year ago,
             | when it was GPT-3 (and LaMDA behind an NDA) rather than
             | ChatGPT et al:
             | https://kitsunesoftware.wordpress.com/2022/06/18/lamda-
             | turin...
        
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