his illustration shows a protein complex at work in brain signaling. It contains two joined protein complexes: SNARE, shown in blue, red, and green, and synaptotagmin-1, shown in orange. The combined complex is responsible for the calcium-triggered release of neurotransmitters from our brain’s nerve cells in a process called synaptic vesicle fusion. In the background, electrical signals travel through a neuron. (SLAC National Accelerator Laboratory)