Recording sympathetic nerve activity in conscious humans and other mammals: guidelines and the road to standardization

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 312; no. 5; pp. H1031 - H1051
• Main Authors: Hart, Emma C., Head, Geoffrey A., Carter, Jason R., Wallin, B. Gunnar, May, Clive N., Hamza, Shereen M., Hall, John E., Charkoudian, Nisha, Osborn, John W.
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 01.05.2017
• Series: Guidelines in Cardiovascular Research
• Subjects: 1972; 1975; 1989; acta physiologica scandinavica; Action Potentials - physiology; american journal of physiology; angiotensin-ii; Animals; autonomic nervous system; awake human-subjects; Baroreflex - physiology; blood pressure; brain research; Bursts; cardiac noradrenaline spillover; Cardiovascular System & Cardiology; Clinical Medicine; congestive-heart-failure; Diagnostic Techniques, Neurological - standards; differential control; Electrodes; had h; Heart rate; high-fat diet; human; human muscle nerves; human skin; Humans; Hypertension; induced hypertension; kberg dl; ki k; Klinisk medicin; lius w; mammal; Mice; mouse; nerve recording; nerves; Nervous system; p177; p425; p567; p65; Peripheral Nerves - physiology; Physiology; pr299; pr337; Practice Guidelines as Topic; rabbit; Rabbits; rat; Rats; Recording; regulation; Review; Rodents; Sheep; Species Specificity; Standardization; Sympathetic nervous system; Sympathetic Nervous System - physiology; v100; v137; v256; v257; v84; blood pressure; mouse; autonomic nervous system; rat; mammal; rabbit; human; sheep; nerve recording
• ISSN: 0363-6135; 1522-1539; 1522-1539
• DOI: 10.1152/ajpheart.00703.2016

Over the past several decades, studies of the sympathetic nervous system in humans, sheep, rabbits, rats, and mice have substantially increased mechanistic understanding of cardiovascular function and dysfunction. Recently, interest in sympathetic neural mechanisms contributing to blood pressure control has grown, in part because of the development of devices or surgical procedures that treat hypertension by manipulating sympathetic outflow. Studies in animal models have provided important insights into physiological and pathophysiological mechanisms that are not accessible in human studies. Across species and among laboratories, various approaches have been developed to record, quantify, analyze, and interpret sympathetic nerve activity (SNA). In general, SNA demonstrates “bursting” behavior, where groups of action potentials are synchronized and linked to the cardiac cycle via the arterial baroreflex. In humans, it is common to quantify SNA as bursts per minute or bursts per 100 heart beats. This type of quantification can be done in other species but is only commonly reported in sheep, which have heart rates similar to humans. In rabbits, rats, and mice, SNA is often recorded relative to a maximal level elicited in the laboratory to control for differences in electrode position among animals or on different study days. SNA in humans can also be presented as total activity, where normalization to the largest burst is a common approach. The goal of the present paper is to put together a summary of “best practices” in several of the most common experimental models and to discuss opportunities and challenges relative to the optimal measurement of SNA across species. Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/guidelines-for-measuring-sympathetic-nerve-activity/