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).
What happens at the neuromuscular junction? One motor neuron (nerve cell) may stimulate a few muscle cells or hundreds of them, depending on the particular muscle and the work it does. One neuron and all the skeletal muscle cells it stimulates are a motor unit. When a long threadlike extension of the neuron, called the nerve fiber or axon, reaches the muscle, it branches into a number of axon terminals, each of which forms junctions with the sarcolemma of a different muscle cell.