Sympathetic Preganglionic Neurons

Sympathetic preganglionic neurons in the lateral horn of the spinal cord are the source of sympathetic outflow to the periphery and the final site for integration of information that arises from central sympathetic premotor neurons. This chapter summarizes knowledge about sympathetic preganglionic neurons that has accumulated over the past twenty years. The first part of the chapter deals with the sympathetic preganglionic neurons themselves, describing their locations, morphologies, neurochemical phenotypes and electrophysiological properties. The second part of the chapter covers the neuronal circuitry that influences the activity of sympathetic preganglionic neurons, including the origin and neurotransmitter content of the synaptic inputs that these neurons receive. The chapter also highlights some of the questions that require answers in order to achieve a better understanding of how this important group of neurons contributes to the control of autonomic function.