Who knows! I'm sure it depends on how accurately you want to simulate a flatworm brain.
I think current AI research has shown that simply representing a brain as a neural network (e.g. fully connected, simple neurons) is not sufficient for AGI.
>>mewpme+Lm
Estimates of GPT-4 parameter counts are ~1.7 trillion, which is approximately 20-fold greater than the ~85 billion human neurons we have. To me this suggests that naively building a 1:1 (or even 20:1) representation of simple neurons is insufficient for AGI.