4 ms·

Over at LessWrong niconiconi recently posted a somewhat pessimistic assessment of the last 10 years of progress on emulating C. Elegans, including OpenWorm: ht

by moyix 5y ago

Over at LessWrong niconiconi recently posted a somewhat pessimistic assessment of the last 10 years of progress on emulating C. Elegans, including OpenWorm: https://www.lesswrong.com/posts/mHqQxwKuzZS69CXX5/whole-brain-emulation-no-progress-on-c-elgans-after-10-years https://www.lesswrong.com/posts/mHqQxwKuzZS69CXX5/whole-brai... Apparently there are some signs that progress is being made again now, though...

nabla9 5y ago
C. Elegans is the perfect first candidate for understanding the whole brain of some animal. It doesn't even have spiking neurons. Whole Brain Emulation of merely 302 neurons would not be that hard if we understood how worm brain and neurons work.
- neatze 5y ago
  > It doesn't even have spiking neurons. What do you mean ? If I recall correctly there was one hobbyist who used Hodgkin-Huxley neurons to emulate movement of warm, it actually trivial task.
  - nabla9 5y ago
    Consider the difference between: Replicating limited outward behaviour with simplified neuron model. vs. Fully simulating the functioning of the neuron so that it does not replicate some observed behaviors, but simulates the brain function accurately at the neuron level. An elegant mind: Learning and memory in Caenorhabditis elegans http://learnmem.cshlp.org/content/17/4/191.long http://learnmem.cshlp.org/content/17/4/191.long
    - neatze 5y ago
      Hodgkin-Huxley neurons are fully functioning neurons as far my understanding goes, furthermore, if not mistaken openwarm simulator has ability to simulate hydrodynamics on cellular levels.
- spywaregorilla 5y ago
  What if neurons aren't the only component of a neurological system that we need to be tracking, and we're not aware of that fact?
  - flatiron 5y ago
    Then that would be exposed as part of this effort and they can go figure out what else to track.
    - spywaregorilla 5y ago
      Would it? It seems openworm has been struggling to work for a long time. How confident are we that the answer is just more effort?
      - w1nk 5y ago
        Where else do you imagine the answer would come from?
        spywaregorilla 5y ago
        That's a difficult question that I cannot answer, but it doesn't mean open worm is a good answer either?
kaijia 5y ago
Recently I looked into this subject and talked with a postdoc researcher. It is interesting to see this discussion on HN. C elegans is far more complicated than the connectome abstraction used in these projects. There are all kinds of ion channels, including new ones recently discovered (https://pubmed.ncbi.nlm.nih.gov/34388373/ https://pubmed.ncbi.nlm.nih.gov/34388373/ ), that are regulated by genes and other physical/biochemical factors in the body that are very poorly understood. We only have slightly better understanding of its brain development recently ( https://www.nature.com/articles/s41586-021-03778-8 https://www.nature.com/articles/s41586-021-03778-8 ). The in vivo research on C. elegans neural system mostly uses the concentration of Ca+ as the neuron activity indicator, which lefts out other details. According to the postdoc that I talked with, we are still very very far from even accurately understanding a single neuron, let alone simulating any neural network completely. Edit: typo

by moyix 5y ago

nabla9 5y ago

C. Elegans is the perfect first candidate for understanding the whole brain of some animal. It doesn't even have spiking neurons. Whole Brain Emulation of merely 302 neurons would not be that hard if we understood how worm brain and neurons work.

neatze 5y ago
> It doesn't even have spiking neurons. What do you mean ? If I recall correctly there was one hobbyist who used Hodgkin-Huxley neurons to emulate movement of warm, it actually trivial task.
- nabla9 5y ago
  Consider the difference between: Replicating limited outward behaviour with simplified neuron model. vs. Fully simulating the functioning of the neuron so that it does not replicate some observed behaviors, but simulates the brain function accurately at the neuron level. An elegant mind: Learning and memory in Caenorhabditis elegans http://learnmem.cshlp.org/content/17/4/191.long http://learnmem.cshlp.org/content/17/4/191.long
  - neatze 5y ago
    Hodgkin-Huxley neurons are fully functioning neurons as far my understanding goes, furthermore, if not mistaken openwarm simulator has ability to simulate hydrodynamics on cellular levels.
spywaregorilla 5y ago
What if neurons aren't the only component of a neurological system that we need to be tracking, and we're not aware of that fact?
- flatiron 5y ago
  Then that would be exposed as part of this effort and they can go figure out what else to track.
  - spywaregorilla 5y ago
    Would it? It seems openworm has been struggling to work for a long time. How confident are we that the answer is just more effort?
    - w1nk 5y ago
      Where else do you imagine the answer would come from?
      - spywaregorilla 5y ago
        That's a difficult question that I cannot answer, but it doesn't mean open worm is a good answer either?

kaijia 5y ago

Recently I looked into this subject and talked with a postdoc researcher. It is interesting to see this discussion on HN. C elegans is far more complicated than the connectome abstraction used in these projects. There are all kinds of ion channels, including new ones recently discovered (https://pubmed.ncbi.nlm.nih.gov/34388373/ https://pubmed.ncbi.nlm.nih.gov/34388373/ ), that are regulated by genes and other physical/biochemical factors in the body that are very poorly understood. We only have slightly better understanding of its brain development recently ( https://www.nature.com/articles/s41586-021-03778-8 https://www.nature.com/articles/s41586-021-03778-8 ). The in vivo research on C. elegans neural system mostly uses the concentration of Ca+ as the neuron activity indicator, which lefts out other details. According to the postdoc that I talked with, we are still very very far from even accurately understanding a single neuron, let alone simulating any neural network completely. Edit: typo