Recording sympathetic nerve activity chronically in rats: surgery techniques, assessment of nerve activity, and quantification

Stocker, S.D. and Muntzel, M.S. Recording sympathetic nerve activity chronically in rats: surgery techniques,assessment of nerve activity, and quantification. Am J Physiol Heart Circ Physiol 305: H1407–H1416, 2013. This review article covers the latest advances in recording chronically from sympathetic nerves focussing on recordings in rats. The article goes in significant details on the methods and provides some nice diagrams for recording from lumbar, renal, and splanchnic nerves. It also has a very good section on "Distinguishing Between Sympathetic Nerve Bursts, Background Noise, and Electrical Artifacts." This would be a good primer for anyone who is just starting to recording from sympathetic nerves or wants a refresher on what to look for in determining very good, versus good, versus bad sympathetic nerve recordings. Another section entitled "Time Course and Reasonable Expectations of Chronic SNA Recordings in Rats" covers topics like the Postimplant recovery period where sympathetic activity tends to be high because of a number of stress-related effects of surgery. The last section covers "Analysis of SNA Signals" and breaks down the signals into components like frequency of bursts versus amplitude of bursts. Since we record all of our raw nerve activity on the Powerlab, this could be a useful way to do some data mining and look for specific changes in sympathetic nerve activity betweeen active and sedentary animals that we might not have seen simply comparing voltages between groups. All-in-all this is a very useful review and I would consider required reading for anyone involved in experiments examining sympathetic nerve recordings, chronic or acutely. ~PJM