[Characteristics of peripheral afferent nerve discharges evoked by manual acupuncture and electroacupuncture of "Zusanli" (ST 36) in rats].
OBJECTIVE
To observe the nerve discharge changes responding to stimulation of "Zusanli" (ST 36) by manual acupuncture (MA) and electroacupuncture (EA), so as to reveal the changing regularity of peripheral nerve response.


METHODS
Thirty male SD rats were used in the present study. After anesthetizing with urethane (75 mg/kg) and dissecting a branch of the sciatic nerve innervating ST36 region in the right hind-limb, the ipsilateral ST36 was stimulated with MA (by lifting and thrusting and rotating the acupuncture needle, 1 manipulation/s) and EA (5 V, 10 V, 15 V, and 3 Hz). Discharges of the nerve tract was recorded for 1 min before, during and after MA or EA stimulation respectively, and analyzed in spike counts.


RESULTS
After lifting, thrusting and rotating the needle, the nerve discharge increased to (74.20 +/- 18.92) spikes/s from (42.20 +/- 1.98) spikes/s of pre-MA (P < 0.05), then turned to (41.40 +/- 14.85) spikes/s immediately after cease of MA. After manual lifting and thrusting the needle, the nerve discharge increased to (60.60 +/- 10.79) spikes/s from (42.00 +/- 3.89) spikes/s before MA (P < 0.05), and returned to (45.00 +/- 18.10) spikes/s immediately after cease of MA. No changes were found after manually rotating the needle (P > 0.05). EA at ST36 by increasing the intensity to 5 V began to elicit similar changes of nerve discharges, and increased significantly in a voltage-dependent manner within 5-15 V. EA at the strength of 15 V could produce a marked increase of nerve discharge, being increased to (64.20 +/- 9.36) spikes/s from (42.60 +/- 3.87) spikes/s before EA (P < 0.05), and then, returned to (48.00 +/- 7.55) spikes/s immediately after cease of EA.


CONCLUSIONS
MA of lifting and thrusting, and particularly that of rotating combined with lifting and thrusting at ST36 can significantly potentiate the discharge activity of the sciatic nerve tract, with the response of the latter being more apparent. EA of ST36 at the strength of 10-15 V has a similar effect. It suggests that both mechanical and EA stimulation of ST36 at a certain intensity can produce a similar change of discharges of the afferent nerve innervating ST36 in the rat.
Li
Wei-min
WM
Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433, China. wmli9110@fudan.edu.cn
Chen
Ying-bo
YB
Wang
Xiao-yan
XY
D015667:Acupuncture Analgesia; D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D015671:Electroacupuncture; D004594:Electrophysiology; D005073:Evoked Potentials, Somatosensory; D008297:Male; D016740:Meridians; D010525:Peripheral Nerves / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley