[Tuna-Fish]

Even if it took a hundred thousand transistors (/transistor-size devices) to emulate a neuron, that wouldn't actually be a problem. Compared to electricity-on-copper, the connections between neurons are slow. When operating on electricity, there are no problems whatsoever in making your brain consist of a million chips that fill a warehouse.

[InclinedPlane]

Indeed. So it might actually be possible to emulate a human brain in hardware rather sooner than we might have thought. Memristors are also memory devices, with access times on the order of modern RAM, and a small multiple of 86 gigabytes is not a huge amount of storage these days. So imagine a 1 billion "neuristor" processor backed by a few hundred GB of memristor storage and operating in a sort of time-shared fashion (load a "brain component" into the neuristor configuration, interface with the memory for a while, then move on to the next component and so forth).