ABSTRACT
Recording the activity of single neurons in the whole animal is a vital component in the study of integrative functions of the nervous system. One relatively simple way of evaluating such activity without significant disruption of the system is to record the action potentials using a suitable microelectrode inserted in the extracellular compartment. The potential recorded from an electrode in the extracellular space is influenced by the electrical currents set up by the neuronal elements around it. Elaborate methods have been developed to study such activity in either anaesthetized preparations or in awake animals without causing pain or distress to the animal. The animals are anaesthetized during the entire procedure and it is important that stable levels of anaesthesia and an excellent physiological state are maintained to enable reliable unit recordings. Usually, the animals are also paralysed so that controlled artificial ventilation can be undertaken.
