Thanks for the response! I think the link you provided includes the ");" at the end, leading to an error page. Removing ");" leads to the article I think you wanted to mention. Anyway am I correct in saying this may allow research to analyze bigger and bigger neural networks (the biological ones)? I remember OpenWorm (http://openworm.org/science.html) which was able to recreate virtually the nematode's brain thanks to a few "maps" of its brain. Could this technology (coupled with the improvements that will come in the next years) allow something of the OpenWorm kind with more and more complex organisms?

To really extract networks, you would need to either image synapses (very, very difficult since they are sub-micron sizes) to determine how cells connect, or image something like calcium potential to infer a circuit of active neurons as a very sparse subset of a larger set of observed cells during a particular kind of neural activity.

One of the authors here; Imaging synapses is really no problem with electron microscopy resolution. In fact, you can see automatically extracted synapses (little spheres) in the video of the blog post, this was done a year earlier already!

Oops, sorry, I have been talking to folks doing en vivo fluorescent imaging and didn't notice that this was electron microscopy!

Not only is the resolution a lot worse for optics, but I understand that the signal to noise ratio is much lower when avoiding destructive imaging methods.

The paper (available at https://sci-hub.tw/https://www.nature.com/articles/s41592-01...) says that the part of the zebra finch brain analyzed had a resolution of 9 x 9 x 20 nanometers. If I'm reading it correctly, should they not be able to analyze synapses, too? At that resolution, shouldn't synapses have been imaged too?

That's correct - I imaged the volume and we extracted the synapses before (https://www.nature.com/articles/nmeth.4206).