Everything your brain does—every memory, decision, emotion and command to move—starts with an electrical signal generated by a neuron. One of the most sophisticated cells in the body, every neuron has two sides. At one end is the tail-like axon, which acts as a data transmission line, sending signals to other neurons. At the other is the neuron’s branching crown of antenna-like dendrites, which receive incoming signals from other cells. The importance of this bipartite biology cannot be overstated; it is the basis for the brain’s incredible abilities.