The human brain is truly awesome.A typical, healthy one houses some 200 billion nerve cells, which are connected to one another via hundreds of trillions of synapses. Each synapse functions like a microprocessor, and tens of thousands of them can connect a single neuron to other nerve cells. In the cerebral cortex alone, there are roughly 125 trillion synapses, which is about how many stars fill 1,500 Milky Way galaxies. This is a visual reconstruction from array-tomography data of synapses in the mouse somatosensory cortex, which is responsive to whisker stimulation.(Credit: Stephen Smith/Stanford) These synapses are, of course, so tiny...