Neurons are the cells that constitute the fundamental working units of the nervous system. The most important function of these cells is to electrically excite their membranes to transmit information from a cell to another. In this article we discuss the basic components of neuronal cells that contribute in creating and distributing information in the nervous system. Neurons spend most of their energy to maintain a difference in electric charge concentrations inside and outside of the cells. The excitable membranes of neurons can alter their permeability to specific types of ions allowing for fast electricity based signals. This is made possible by a series of important membrane proteins that allow ions to move across the cellular membrane either passively or through the use of energy. To conclude we give a brief introduction to the most important techniques used to analyze and manipulate neuronal signals in vitro and in vivo.