Introduction to Sympathetic Microneurography

Sympathetic microneurography is an electrophysiological method to record directly from human peripheral nerves’ sympathetic neural traffic leading to the muscle and skin called muscle sympathetic nerve activity (MSNA) and skin sympathetic nerve activity (SSNA). In this chapter, the author explains (1) what is microneurography, (2) the recording technique of microneurography, (3) how to identify MSNA and SSNA, and (4) applications of sympathetic microneurography. Sympathetic microneurography is very useful to analyze sympathetic neural functions in humans by observing directly neural traffic in postganglionic multiple and single sympathetic efferent fibers innervating the muscle and skin under physiological and pathological conditions. MSNA which regulates peripheral vascular resistance in skeletal muscles is particularly important for controlling blood pressure homeostasis, while SSNA which regulates mainly sweat glands and skin blood vessels plays important roles in thermoregulation. Recordings of MSNA and SSNA have been widely applied to analyze sympathetic mechanisms in various disease conditions, as well as stressful situations when the human body is exposed to various environmental conditions.