Extracellular Single-Unit Recording Methods

Abstract

Since their refinement in the early 1950s, extracellular, single-unit recording methods have been used to obtain a wealth of data about the properties of CNS structures. The applications of the technique have been diverse: extracellular microelectrodes have been used to map the potential fields of single discharging neurons in order to answer fundamental questions about the excitability of CNS dendrites (Frank and Fuortes, 1955; Fatt, 1957; Nelson and Frank, 1964), and more recently they have been used to study the behaviorally related discharge patterns of CNS neurons in the awake, moving animal (e.g., Evarts, 1968; Mountcastle et al., 1975). To an appreciable extent, the exciting new neuroanatomical tracing methods that have been developed over the past decade (cf Jones and Wise, 1977) have supplanted extracellular recording methods as a technique for tracing CNS connectivity patterns. However, the single-unit recording method is the technique of choice for studies of the responses of central neurons to sensory stimuli and of their behaviorally related firing patterns in the alert, moving animal. Moreover, many applications remain for the tracing of functional network connections on a microanatomical scale.