I remember reading a book many years ago which talked about the "hormonal bath" in the body being actually part of cognition, such that thinking of the brain/CNS as the functional unit is wrong (it's necessary but not sufficient).
This ties in with the philosophical position of Externalism (I'm very much into the Process Externalism of Riccardo Manzotti). The "thinking unit" is really the whole body - and actually finally the whole world (not in the Panpsychist sense, quite, but rather in the sense of any individual instance of cognition being the peak of a pyramid that has roots that go all the way through the whole).
I'm as intrigued and hopeful about the possibility of uploading, etc., as the next nerd, but this sort of stuff has always led me to be cautious about the prospects of it.
There may also a lot more to be discovered about the brain and body too, in the area of some connection between the fascia and the immune system (cf. the anecdotal connection between things like yoga and "internal" martial arts and health).
I'm really skeptical of claims like « the "thinking unit" is really the whole body », they tend to discard quantitative considerations for purely qualitative ones.
Yes, the brain is influenced, and influences, the whole body. But that doesn't mean the whole body has the same importance in the thinking. The brain is also influenced by lots of external factors (such as ambient light or sounds, ...) if as soon as there is a "connection" between two parts you say "it's the whole system that does the processing", you'll just end up ...
Kipnis et al found a new part of the lymphatic system. It goes into the brain.
The fact that we still get surprised by new elements of the brain suggests that there quite a lot we still don't know about the brain and uploading might be harder than previously believed.
Given that these vessels were hard to find, it will be interesting to see whether other hard to find vessels will be discovered in the coming years.
Besides their Nature article Structural and functional features of central nervous system lymphatic vessels, there a good article on NeuroscientistNews titled Missing link found between brain, immune system -- with major disease implications.