Direct measurement of human sympathetic nerve conduction velocity.
We evaluated a method for direct measurement of conduction velocity (CV) in sympathetic nerves in humans using a double-recording method of skin sympathetic nerve activity (SSNA) by microneurography. SSNA in the tibial nerve was recorded simultaneously at proximal and distal sites in the popliteal fossa (short-distance study) or at the popliteal fossa and ankle (long-distance study). In both studies, CVs were determined by dividing the interelectrode distance on the skin by the difference in conduction time between the rising-phases (rising-phase analysis) or peaks of the integrated bursts (peak-to-peak analysis). The measurement using long distance and peak-to-peak analysis had the highest accuracy; it is an orthodromic conduction measurement, is unrelated to eliciting stimulus, has high temporal resolution, and is not affected by the effector organ conditions. The average CV of resting SSNA was 0.93 +/- 0.09 m/s.
Kondo
Masahide
M
Department of Autonomic Neuroscience, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan.
Iwase
Satoshi
S
Mano
Tadaaki
T
Kuzuhara
Shigeki
S
D000200:Action Potentials / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D004558:Electric Stimulation; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods; D014644:Genetic Variation / Q000502:physiology; D006801:Humans; D008297:Male; D036421:Nerve Fibers, Unmyelinated / Q000502:physiology* / Q000648:ultrastructure; D009431:Neural Conduction / Q000502:physiology*; D010812:Physical Stimulation; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012867:Skin / Q000294:innervation; D013545:Sweat Glands / Q000294:innervation / Q000502:physiology; D017779:Sympathetic Fibers, Postganglionic / Q000166:cytology / Q000502:physiology*; D013979:Tibial Nerve / Q000166:cytology / Q000502:physiology; D013997:Time Factors; D014666:Vasomotor System / Q000502:physiology