If you could pause time for an instant and make yourself small enough to discern individual molecules, the far right of this image is what you might see when one brain cell communicates with another across a synapse—the point of contact between two nerve cells. How the brain senses, thinks, learns and emotes depends on how all its nerve cells, or neurons, communicate with one another. And as a result, many laboratories are working feverishly to understand how synapses function—and how psychiatric drugs, which target them, improve patients’ lives.
Yet neuroscientists are hobbled by the fact that synapses are extremely complex, vanishingly small and extraordinarily fast. Thanks to the coordinated efforts of over 1,400 types of molecules, one neuron communicates with another by spitting out chemical neurotransmitters that carry its message across a thin gap to a receptive surface on its partner. The only way to provide a full account of what goes on at the synapse is to build a computer model that is as realistic as possible. The hope is that running a moment-by-moment, molecule-by-molecule simulation will yield novel insights that could then be tested experimentally.