In this chapter I describe the reflex patterns for different groups of autonomic neurons, in particular sympathetic neurons. For other groups of autonomic neurons that have not yet been investigated in this way, I will draw indirect conclusions by analogy to those that have been investigated. Using this approach we gather information about the functional specificity of different neurons, about the relation between activity in certain types of neurons and the responses of the target tissue as well as information about the principal organization of the central circuits that determine the discharge pattern of these neurons (see Chapters 8 to 11). Thus, the experimental data described in this chapter are an important cornerstone of this book: they show that each autonomic pathway exhibits a characteristic pattern of discharge and that this is dependent on the structure of the central circuits in the neuraxis and the synaptic connections of these circuits with the different groups of afferent input to the neuraxis. This type of analysis gives the ultimate underpinning for the concept that the autonomic nervous system consists of functionally distinct building blocks (Jänig and McLachlan 1992a, b). As I have emphasized in Chapter 3, this description does not show how these autonomic systems function during ongoing regulation of autonomic function. This will be discussed in Chapters 5 to 10.

A similar approach has been used for the analysis of the somatomotor system.