Another interesting paper demonstrating that neural tissues can be effectively grown around mesh electrodes, providing both a scaffolding function as well a recording and stimulation functions. http://faculty.engr.utexas.edu/xie/xie/publications/ultrafle...
Neuroscience has been rapidly leveling up recently, its increasingly believable that high bandwidth bidirectional neural interfaces (at the cellular level) are on the horizon. DARPA was pitching this a few years ago (NESD) and it was pretty far out, but now see Kernel and Neuralink and the 10 or so companies partnered in to those efforts mostly-successfully developing all kinds of technologies required by this roadmap (disclosure: including my own).
This means getting inside the brain, right ? do you see it happening for regular brain augmentation, and not just serious medical issues?
It would be kind of crazy if we develop full AI by literally using brains in vats. But it makes sense (even if it is horrifying). Meat is cheap, and the brain is like an exa-OPS computer running on 20 Watts of power. If you could solve the interface problem and figure out how to actually use it practically, brain is like 6 or 7 orders of magnitude cheaper than the next-cheapest computing substrate. That's like half a century of Moore's Law (and Moore's Law is basically over now... much slower pace, at least).
(Here's an example using rat neurons: https://singularityhub.com/2010/10/06/videos-of-robot-contro... And this one: https://www.newscientist.com/article/dn6573-brain-cells-in-a... )
If I could pick what platform I run on, it'd be hardware (and I hope such hardware eventually comes along).
"Cattle, not pets."
(I do realize the pretty horrific undertones of this discussion.)
There is some research going on in using spintronics for neural network, and I think that both density and power usage would be a fraction of a biological system.
There is probably a long way until we can emulate human brains, but for generic neutral networks, I think electronics or spintronics is the probable route.
EDIT:And technically brains are general computing devices. Just really inefficient ones. Emulating logic in wetware is highly inefficient (and usually requires an external memory device, like pen and paper, though pure wetware memory also works in some especially skilled individuals, although still with severe capacity limitations). Of course, emulating wetware in logic isn't terribly efficient, either.
http://www.cnn.com/2004/TECH/11/02/brain.dish/
[edit] didn't see the UF link below.
Already been done after a fashion 13 years ago. Would be interesting to see what further research has resulted in.