Conventional equipment for recording of membrane potentials in research laboratories includes a microelectrode, headstage, micromanipulator, amplifier (electrometer), oscilloscope, a timing device and usually a loudspeaker system (Figure 5.1). These days some research laboratories are using computers to replace the timing device and oscilloscope (e.g. MacLab system); with appropriate software the computer screen can emulate an oscilloscope or chart recorder. Thus, it is unnecessary to have all the equipment shown in Figure 5.1.