[Effects of electroacupuncture of "Neiguan" (PC 6), "Zhongwan" (CV 12) and "Zusanli" (ST 36) on electrical activities of neurons subnucleus reticularis dorsalis in rats].

Objective: To compare the effects of electroacupuncture (EA) stimulation of "Gastric Problem Formula" ["Neiguan" (PC 6), "Zhongwan" (CV 12) and "Zusanli" (ST 36)] on electrical activities of neurons of medullary subnucleus reticularis dorsalis (SRD) of the rat.
Methods: Experiments were performed on SD rats anesthetized by 10% urethane (1.0-1.5 g/kg). Under artificial ventilation and immobilization (2% gallamine triethiodide, 5 ml/kg), extracelluar discharges were recorded by glass micropipettes inserted into SRD of the medulla (Caudal to the Obex: - 1.0 - -2.0 mm, L/R= 0.5-1.5 mm, H: 0.6- 1.5 mm below the medullary surface). Following getting stable recordings, the acupuncture needle inserted in "Neiguan" (PC 6) was manipulated moderately (twisting range: 120 degrees, frequency = 80 times/min) for 30 s. The same manipulation was performed at "Zhongwan" (CV 12) and "Zusanli" (ST 36) separately.
Results: After moderate acupuncture stimulation, in the recorded 13 SRD neurons, the discharges were increased from (1.67 +/- 0.35) spikes/s to (17.55 +/- 1.40) spikes/s for "Neiguan" (PC 6), from (2.35 +/- 0.43) spikes/s to (16.96 +/- 1.83) spikes/s for "Zhongwan" (CV 12), and from (1.83 +/- 0.37) spikes/s to (17.39 +/- 1.58) spikes/s for "Zusanli" (ST 36). No apparent differences were found among 3 acupoints in their responses to manual manipulation.
Conclusion: Moderate acupuncture stimulation of "Neiguan" (PC 6), "Zhongwan" (CV 12) and "Zusanli" (ST 36) can effectively activate spontaneous discharges of SRD neurons in the rat.