I was only referring to the internal processes of a cell. We don't need to simulate 90+% of the biochemical processes in a neuron to get an accurate simulation of that neuron - if we did it'd pretty much fuck up our understanding of every other cell because most cells share the same metabolic machinery.
The characteristics of the larger network and which cells are involved is an open question in neuroscience and it's largely an intractable problem as of this time.