Nice find, another interesting read... But i also agree, i think a rats brain is much more likely/possible. then maybe with more development we could get to the level of a chimpanzee or something, but i think the human brain would take a long time.
We haven't even "decoded" the human brain yet-it has around 100billion neurons. So yea a rat's would be much more plausible atm.
The blockchain *might* be a good fit because of it's decentralization. Our body, how our brain reacts with the various parts(via spinal cord) could be compared to a decentralized network in some ways. Most, if not all, our memories are stored in the brain, the blockchain stores transactions on a permanent ledger, mining "powers" the blockchain and allows for changes to happen via consensus, the brain "powers" the body and allows at least for voluntary changes(There are things we do that are involuntary, such as breathing etc), etc and etc.