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An adult fruit fly brain has been mapped

economist.com

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Re: An adult fruit fly brain has been mapped

#71

Post by mrguyorama »

dang wrote: post #39
droideqa wrote: post #14

There is this interesting past post: Whole-brain connectome of the fruit fly (2023) https://news.ycombinator.com/item?id=36568609

Thanks! Macroexpanded: Whole-brain connectome of the fruit fly - https://news.ycombinator.com/item?id=36568609 - July 2023 (94 comments) The connectome of an insect brain by Winding et al. - https://news.ycombinator.com/item?id=35112234 - March 2023 (1 comment) Map of an Insect’s Brain - https://news.ycombinator.com/item?id=35111371 - March 2023 (119 comments) The Connectome of an Insect Brain - https://news.ycombina…

Out there question: Do you have a hand crafted database of these setup or some sort of macro to take the output of the search api and form it like this, or are you hand editing these lists?

Re: An adult fruit fly brain has been mapped

#72

Post by ruthmarx »

mjburgess wrote: post #3

It was my understanding that all this connectome-based research was largely a deadend, because it doesnt capture dynamics, nor a vast array of interactions. if you've ever seen neurones being grown (go search YT), you'll see it's a massive gelatinous structure which is highly plastic and highly dynamic. Even in the simplest brains (eg., of elgans), you get 10^x exponential growth in number of neurones and their conne…

> It was my understanding that all this connectome-based research was largely a deadend,

There's obviously something to it or implementing what we map in software wouldn't give results as accurately as they do.

Re: An adult fruit fly brain has been mapped

#73

Post by bryan0 »

generuso wrote: post #43
fabiensanglard wrote: post #5

What does it mean "mapped". Does it mean we know what each nerve/axon does?

Unfortunately, not. We get the graph of the connections, but there are tons of essential parameters that are not captured. Such as the synaptic weights, the complex non-linear dynamics of the real neurons, their intricate modulation by various chemicals, etc. For example, after the connectome of the worm were finished, despite it being quite small, for many years it proved to be impossible to simulate the dynamics, b…

> after the connectome of the worm were finished, despite it being quite small, for many years it proved to be impossible to simulate the dynamics, because of so many unknown parameters.

Apparently they have been able to simulate dynamics with the fruit fly connectome(?) [0]:

> researchers used the connectome to create a computer model of the entire fruit-> fly brain, including all the connections between neurons. They tested it by activating neurons that they knew either sense sweet or bitter tastes. These neurons then launched a cascade of signals through the virtual fly’s brain, ultimately triggering motor neurons tied to the fly’s proboscis — the equivalent of the mammalian tongue. When the sweet circuit was activated, a signal for extending the proboscis was transmitted, as if the insect was preparing to feed; when the bitter circuit was activated, this signal was inhibited. To validate these findings, the team activated the same neurons in a real fruit fly.

[0]: https://www.nature.com/articles/d41586-024-03190-y

Re: An adult fruit fly brain has been mapped

#74

Post by lawrenceyan »

mjburgess wrote: post #3

It was my understanding that all this connectome-based research was largely a deadend, because it doesnt capture dynamics, nor a vast array of interactions. if you've ever seen neurones being grown (go search YT), you'll see it's a massive gelatinous structure which is highly plastic and highly dynamic. Even in the simplest brains (eg., of elgans), you get 10^x exponential growth in number of neurones and their conne…

Connectomes are like a static graph of a neural network.

But it's the flow of information as signals pass through nodes where everything actually happens.

Re: An adult fruit fly brain has been mapped

#76

Post by notahacker »

s1artibartfast wrote: post #63
aithrowawaycomm wrote: post #62

Earlier quoted context omitted.

Knowing what the individual neurons actually do. The connectome is like an electrical schematic but you don't even know which components are resistors, inductors, etc (let alone the resistances and inductances). The connectome for the C. elegans nematode was mapped in the 1980s and the OpenWorm project has successfully simulated all non-neuronal cells. But they are very far from simulating the brain abd it will take…

I think it's even more complex. The neurons are like individual raspberry pi. They have both complex logic and physical memory.

Yeah, I think it's close to "what steps exist between observing the network topology of the internet and being able to emulate a Google search query?"

There's plenty of value to knowing where the datacentres are and which regions are active under which circumstances, but none of that is telling you what the internet is thinking...

Re: An adult fruit fly brain has been mapped

#77

Post by phyzome »

dekhn wrote: post #57
willcipriano wrote: post #37

50 years from now I am dying in a hospital bed, the nurse informs me that my consciousness will be uploaded to a computer with all the other brains, a digital heaven if you will. Get there and its full of flies.

No, beetles (JBS Haldane said god has an "inordinate fondness for beetles")

That may be so, but scientists have an inordinate fondness for flies.

Re: An adult fruit fly brain has been mapped

#78

Post by nonameiguess »

aithrowawaycomm wrote: post #62
holtkam2 wrote: post #60

What hard steps exist between mapping the physical structure of the brain and simulating a running one via software?

Knowing what the individual neurons actually do. The connectome is like an electrical schematic but you don't even know which components are resistors, inductors, etc (let alone the resistances and inductances). The connectome for the C. elegans nematode was mapped in the 1980s and the OpenWorm project has successfully simulated all non-neuronal cells. But they are very far from simulating the brain abd it will take…

I'm frankly not sure it will ever be possible. Forget about observing the inside of a running neuron. In spite of how confidently people on the Internet will tell you their body fat percentage, in reality we can't even accurately measure that without killing you first.

Re: An adult fruit fly brain has been mapped

#79

Post by charlescurt123 »

_giorgio_ wrote: post #47

Is this correct? It this like knowing only this: which neuron is connected to which neuron But you don't know: the values of the weights (the value of the neuron, or the parameters) the activation functions what circuit do neurons implement (fully connected? CNN?)

I believe they do know this.

However the real challenge would be:

1. bring this mapping into a AI framework for inferencing 2. We don't know the "OS" on how it runs. Just randomly triggering a neuron probably wouldn't work as there is a lot of other factors that trigger neurons.

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