From the latest issue of Biomedical Computation Review, a very readable article on the state of research into how our brains work. From the longer term perspective of longevity, this is important: we'd like to be able to replace our neurons with something more durable further down the line. "For a century, neuroscientists have dissected, traced, eavesdropped on, and are now compiling a seemingly endless cast of players in the nervous system. As we keep gathering more and more molecular details, how do we know when we know enough? ... Some have decided it's time to just go ahead and create a brain in silico. And to a surprising extent, they've done it: Labs around the world are populated with autonomously functioning [so far non-human, proof of concept] brains based on what we know so far. These simulations match what happens at the cellular level in the brain when the nerve cells, or neurons, that make up the brain pump ions and produce electrochemical activity that propagates across the synapse from one neuron to another. ... We can simulate the neuronal dynamics beautifully so that you can't tell the difference between the model and real neurons."

Link: http://www.biomedicalcomputationreview.org/5/2/7.pdf