Nina is a neuroscientist who works at the Glasgow Science Center. She is fun, bubbly, but has the presence and authenticity of a real scientist who knows her stuff. The Neurons are characters who live in Nina's brain and, like real human neurons, send messages from her brain to the parts of her body which control her senses. Nina has some dialogue with the neurons, but most of their activity and chatter is among themselves, commenting on the action while "looking out" from Nina's brain.