How do you simulate something you don't understand?
The basic problem here is that we don't understand what a neuron does, so how would we model it?
The basic problem here is that we don't understand what a neuron does, so how would we model it?
We understand lots of aspects of neurons and can model those. See the wikipedia page for some examples of well-understood principles.
It seems the DeepMind rat brain didn't really try to get close to biological neurons but still produced outputs close to a real brain. (vid from here for about 2 mins https://youtu.be/hIuXXvWY6-4?t=125)