Neurons are cells in your brain. Shaped like little stars, they flicker and fire off signals to each other. The signals travel up and down the long tendrils, called dendrites, extending out from each point of a neuron’s star-shaped body. Chained into circuits like Christmas lights, neurons’ electrical firing forms the glimmers of our thoughts and actions.

But the process by which an individual neuron decides to fire is not completely understood. Every neuron can receive signals from other brain cells through its dendrites. Some of these excite the neuron, pushing it closer to firing, while others calm it down.   Read more about “Testing the Fluorescent Proteins That Light Up the Brain“.