Central nervous system (CNS) adrenergic neurons are located exclusively in the medulla oblongata (1). The metabolism of CNS adrenaline, its turnover rate, and its pharmacology were intensely studied in the late 1970s (reviewed in ref. 2). Since then, the study of CNS adrenergic neurons has been the purview of integrative physiologists interested in stress, autonomic regulations, and the neural control of blood pressure and glucose. The CNS contains three clusters of adrenergic neurons: C1, C2, and C3 (1). The main focus of this chapter is on the C1 neurons, especially those with spinal projections that are most important for sympathetic control and blood pressure regulation (3-6).