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.
Just a frivolous comment, but I'm reminded of this classic SF story.
BTW, the "Robert von Engen" in the story is clearly John von Neumann, Engen's book “Logical Control: The Computer vs. Brain” is Neumann's “The Computer and the Brain”, and Engen's paper “Memory Registers: Stimulation Criteria” takes its title from two sections of Neumann's book. I don't know how many other real-world correspondences there are. In the real world, unlike the story, Neumann's book was published posthumously.