Information in the nervous system is conveyed by impulses called action potentials: large, transient electrochemical changes in a neuron's membrane. Though action potentials are a basic feature of neurons, teachers often have trouble explaining this neurophysiological concept, and students have difficulty understanding it. While easy-to-understand analogies exist to help students conceptualize the heart as a pump or the kidney as a filter, there are fewer examples to provide insight into the workings of the nervous system. This void may be responsible in part for the lack of discussion about the nervous system from elementary school through introductory college courses despite the inherent appeal of understanding the brain and behavior. In this article, the author presents an analogy and demonstration using a sparkler (a wire coated with combustible or explosive material similar to gunpowder) and a frying pan to illustrate how neurons generate and propagate action potentials. Analogies have been used for centuries to help explain scientific concepts, and are effective in helping students integrate new knowledge (Glynn et al., 1995). (Contains 3 figures.)