ABSTRACT
In the previous chapter we saw how electron and optical micrographs have vastly increased our knowledge of neuron structure. The present chapter will deal with some of the methodology that is helpful in examining the function of these same cells. The biology of the neuron (its low power levels and small size) requires that a specialized technology be used to detect and record any physiological response. As we saw in Chapter 2, because the neuron is generally quite small, microelectrodes must be used for detailed studies of membrane responses. The small size of the neuron also specifies other features of the recording apparatus. For example, in order to keep individual cells in contact with an electrode for extended periods of time, a mechanical framework is required that allows smooth control over the microelectrode position while holding the animal preparation in a rigid position. To locate and maintain a response from a single neuron, the microelectrode manipulator must be capable of controlled, repeatable movements as small as a micron. Furthermore, the low power levels of the neuronal response require that the electrochemical signals be amplified, just as their intrinsic rapidity demands that some means of storing a record of their occurrence for later, sustained examination must be present in the system.
