An experimental study on the peripheral autonomic nerve potential in the spinal cord injury model by microneurography
The purpose of the present investigation was to analyze the effects of spinal cord injury (SCI) on the peripheral sympathetic nerve, skin sympathetic activity (SSA), and muscle sympathetic activity (MSA). To do this sixteen male Japanese white rabbits weighing 1.0 kg-1.5 kg were used. The exposed spinal cord was transected at various levels. Microelectrodes were placed on the muscular branch and on the cutaneous branch, and they were separately induced using a 0.5 -5 kHz amplifier. The data were calculated with the time reset integration value at 60 seconds.
Results: It is usually satisfactory to considered that the peripheral sympathetic fibers from T1-3 generally pass up through the sympathetic chain to the upper extremities, and that fibers from T9-11 pass up through the sympathetic chain to the lower limbs. In the electrophysiological properties studied, the SSA could not be recognized as a spontaneous activity. On the other hand, the MSA could be recognized as a spontaneous regular activity which synchronizes with the R wave of the electrocardiogram.
Conclusions: The MSA potentials synchronized with the heart rate, and they seem to correlate with the body homeostasis. The existence of a central regulatory mechanism is suggested from those findings not only in vital rhythms, such as the heart rate variability but also in the MSA.