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OpenWorm – A computational model of C. elegans worm

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Re: OpenWorm – A computational model of C. elegans worm

#111

Post by dekhn »

szundi wrote: post #20
inglor_cz wrote: post #12

Earlier quoted context omitted.

This. Submarines don't swim like fish, airplanes don't fly like birds and cars don't run like gepards. Edit: I am surprised at the downvotes. In general, we learn from the nature, but aping it usually proved too difficult and often unpractical at the same time. Do we really want to replicate worm intelligence for practical purposes, or do we want something different? I would say that a machine which can, say, analyze…

And for some reason it is because somehow life is not able the produce rotating axles?

You mean like this? https://en.wikipedia.org/wiki/Flagellum

Re: OpenWorm – A computational model of C. elegans worm

#112

Post by [deleted] »

chromanoid wrote: post #23
circuit10 wrote: post #8

Earlier quoted context omitted.

Replicating something exactly is a lot harder than making something that does the same thing in a different way. We can build planes that travel far faster than a bird could but that doesn’t mean it’s easy for us to exactly replicate how a bird flies, so I don’t think this says anything about how far away we are from a superintelligence

It's not only about exact simulation. And we actually do understand how birds can fly on a mechanical basis. This is not true for C.elegans' inner workings.

[deleted]

Re: OpenWorm – A computational model of C. elegans worm

#113

Post by edwinksl »

pouulet wrote: post #84

Reminds me of the first episode of Devs ( https://www.imdb.com/title/tt8134186/ ) where an artificial intelligence engineer does a demo about syncing, and then predicting the future movements of a nematode worm. Great show by the way!

Creepy stuff with creepy implications, pretty fun show!

Re: OpenWorm – A computational model of C. elegans worm

#114

Post by nycticorax »

burning_hamster wrote: post #60
weinzierl wrote: post #27

Earlier quoted context omitted.

In addition to that, these neurons are also quite different from the ones in mammals, "The neurons do not fire action potentials, and do not express any voltage-gated sodium channels." [1] That makes the fact that it can develop a nicotine addiction even more fascinating. "Nicotine dependence can also be studied using C. elegans because it exhibits behavioral responses to nicotine that parallel those of mammals. Thes…

> "The neurons do not fire action potentials, and do not express any voltage-gated sodium channels." This an old and incorrect belief that largely derives from the difficulty of putting electrodes into their teeny, tiny neurons. Close relatives of C elegans that are larger (and hence more easily experimented on) do have action potentials, and for some neurons in C elegans, we also have good evidence of action potenti…

Well, the 'canonical' action potential is mediated by sodium currents, so it's maybe not surprising that people concluded that C elegans don't have APs given that a) they don't have any genes for voltage-gated sodium channels, and b) when people had recorded from C elegans neurons (it's hard but not impossible), they had never seen action potentials. (So it's not like no one had looked, and then had concluded that they don't exist. They looked and didn't see them.) In the paper that originally reported APs in C elegans (Liu et al 2018), they were looking in a specific neuron (AWA), and they had to elicit a 'plateau potential' by depolarizing the cell for a while before the spikes were revealed, riding on top of the plateau.

The APs discovered by Liu et al (2018) are generated by calcium, not sodium currents, so one could even argue that they aren't action potentials in the strict sense. Also, they seem to be rather difficult to elicit, and it's still not clear whether neural computation in C elegans is mostly AP-mediated, or if APs are the exception rather than the rule.

Liu, Q., Kidd, P. B., Dobosiewicz, M. & Bargmann, C. I. C. elegans AWA olfactory neurons fire calcium-mediated all-or-none action potentials. Cell 175, 57–70 e17 (2018) https://doi.org/10.1016/j.cell.2018.08.018

Re: OpenWorm – A computational model of C. elegans worm

#115

Post by ben_w »

mrguyorama wrote: post #105
ben_w wrote: post #98

Earlier quoted context omitted.

Why does it matter how it works? The 3.2 billion base pair model that is my genome doesn't understand the physics or the chemistry.

That's entirely wrong. The interactions of proteins and amino acids and ions IS, at a fundamental level, the evaluation of physics over time.

I'm not saying it isn't physics, I'm saying it doesn't know what the physics is.

We're physics too, but we don't know how it all fits together.

If a sub-part of us that knows less than we do can make a copy of us, despite not knowing how it all works, that's an existence proof that we don't need to understand how it all works to make a copy of us.

Re: OpenWorm – A computational model of C. elegans worm

#116

Post by nycticorax »

cout wrote: post #99
burning_hamster wrote: post #60

Earlier quoted context omitted.

> "The neurons do not fire action potentials, and do not express any voltage-gated sodium channels." This an old and incorrect belief that largely derives from the difficulty of putting electrodes into their teeny, tiny neurons. Close relatives of C elegans that are larger (and hence more easily experimented on) do have action potentials, and for some neurons in C elegans, we also have good evidence of action potenti…

How did researchers before that explain what the neurons do if they believed they did not have action potentials? Did they believe communication was done solely through chemical messaging?

You don't need spikes to have computation. Deep networks don't have spikes.

Re: OpenWorm – A computational model of C. elegans worm

#118

Post by badrequest »

Maxion wrote: post #55
miohtama wrote: post #46

Earlier quoted context omitted.

Next: OpenSmoker.py

Lol imagine your IDE becoming addicted to smoking, and refusing to auto-complete or save files before you buy it more virtual cigarettes.

shhhhh, you're giving them ideas!

Re: OpenWorm – A computational model of C. elegans worm

#119

Post by hwillis »

lz400 wrote: post #75

I looked at this a few years back. I've always kept some hope that the Kurzwellian eschatology had some validity. You know, first we simulate a C.elegans and once that's done, it's only a matter of scale up before we can simulate a human and then boom singularity sky. And, really, how difficult is it to simulate a silly worm? after all the connectome is there, we know all the neurons and their connections, should be…

> the connectome is there, we know all the neurons and their connections

No- each synapse has its particular neurotransmitters, and the distance, size, shape, number of receptors, and associated glial cells have very large impacts on transmission. The distance and thickness of axons also impacts the strength of signal delivered. That's all very hard to measure.

Neurons are also very sensitive to signal strength and timing. Eg inhibitory synapses work by opening holes in the cell wall, causing them to leak charge over time. You get that rate slightly wrong and it can hugely change the behavior of the cell.

The connectome is a bit like an untrained model of insane complexity, and each neuron has several weights that describe behavior over time as well as in direct response to signals. Without the weights it can't be emulated.

Re: OpenWorm – A computational model of C. elegans worm

#120

Post by dekhn »

bombolo wrote: post #3
c7DJTLrn wrote: post #2

So is this an exact digital replica of a worm?

How can we exactly replicate something if we don't even know all the laws of physics?

If the "something" never exploits a particular law, then in principle you could simulate it if you knew all the laws that actually applied (imagine a hypothetical biological organism that never exploited or experienced quantum entanglement).

But strictly speaking, as we understand it, it's not possible to replicate something exactly without recapitulating the exact laws and running a deterministic simulation, which is not practical.

I don't think anybody is really attempting to exactly replicate things, but rather to create a physical model which can be calcualted and contains enough similarity or transferrability to be able to make accurate generalized predictions about the behavior of the simulated system. How and why that works with modern math methods is still somewhat mysterious. The most useful thing written about that so far is https://en.wikipedia.org/wiki/The_Unreasonable_Effectiveness...

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