I'd say a single neuron should be understandable given that the network effects DO NOT have sufficient impact. Given that "sufficient impact", then the "system

I'd say a single neuron should be understandable given that the network effects DO NOT have sufficient impact. Given that "sufficient impact", then the "system understanding itself" issue arises. However, if you believe the neuron is the same as the neuron in the worm, then the concept of how it works should (by my best guess and nothing else) be adequately simple for human understanding.