Brain upload is a sci-fi invention; using a T1, DWI, fMRI, EEG and behavioral data to build a realistic model of a subject's brain is today's neuroscience.
I will echo this point. I don't think I've met anyone in the field of neuroimaging who sees mind uploading as plausible. There's simply too much noise in the data for that sort of thing. Even simplified simulations such as the Human Brain Project require so much computing power that modeling a single mind is prohibitive; I can't imagine trying to perform whole-brain emulation accurately and practically without incurring more cost than it's worth. Wetware is good enough for me.
This step from (1) to (2) is a common assumption that most people are unwilling to reconsider, but it's equally possible to reject bottom-up modeling and ask what are the high-level constraints on brain activity that shape and direct it. This is what we do with the data I mentioned (T1, EEG, etc).
But you want the dendrites, too, not just cells.
e.g. the Human Connectome Project is still working on capturing the macroscale connectome, that is, high level structures only. Recording the microscale connectome, that is, the neuronal structure, currently requires destroying the brain you're analysing.