At any moment, each of these specialized brain neurons might be receiving multiple messages from multiple sources, but is only selectively responding to certain information about the timing or frequency of the impulses it is receiving. Related Stories.
Methods for measuring sympathetic nervous system activity. Heart rate variability (HRV), the beat-to-beat variation in heart rate, is an indirect method of measuring autonomic nervous system activity, with contributions from both the sympathetic and parasympathetic nervous systems.ine electrodes are used to record 'bursts' of activity from multiple or single afferent and efferent nerve axons in the skin and muscle. The common peroneal nerve is typically chosen for this method (because it is easily accessible) and measures the efferent postganglionic muscle sympathetic nerve activity (MSNA).
Sympathetic nervous system. The sympathetic nervous system (SNS) is part of the autonomic nervous system (ANS), which also includes the parasympathetic nervous system (PNS). The sympathetic nervous system activates what is often termed the fight or flight response. Like other parts of the nervous system, the sympathetic nervous system operates through a series of interconnected neurons. Sympathetic neurons are frequently considered part of the peripheral nervous system (PNS), although there are many that lie within the central nervous system (CNS). Sympathetic neurons of the spinal cord (which is part of the CNS) communicate with peripheral sympathetic neurons via a series of sympathetic ganglia.