Exteroceptive, proprioceptive, and sympathetic activity recorded with microelectrodes from human peripheral nerves

With tungsten microelectrodes percutaneously inserted into human peripheral nerve fascicles, in vivo recordings of single-unit action potentials can be obtained from different types of myelinated and unmyelinated nerve fibers. This technique of microneurography has provided a great deal of information about (1) the sensory innervation of the human skin, with its mechanoreceptive, thermoreceptive, and nociceptive functions, (2) the proprioceptive innervation of human skeletal muscles, special attention being devoted to the motor control functions of the muscle spindles and the fusimotor system, and (3) the sympathetic innervation of autonomic effector organs in skin and muscle, with its significance for, for example, regulation of temperature and blood pressure. The technique has its main application not as a routine procedure in clinical diagnostic work but as a research tool in basic physiologic and pathophysiologic studies.