Effect of Electroacupuncture at ST36 on Gastric-Related Neurons in Spinal Dorsal Horn and Nucleus Tractus Solitarius

Abstract

The aim of this study was to observe the effect of electroacupuncture (EA) at the ST36 acupoint on the firing rate of gastric-related neurons in the spinal dorsal horn (SDH) and nucleus tractus solitarius (NTS). There were different effects of gastric distention in SDH and NTS in 46 male Sprague-Dawley rats. In 10 excitatory neurons in SDH, most of the neurons were inhibited by homolateral EA. The firing rates decreased significantly (P < 0.05) in 10 excitatory gastric-related neurons in NTS; the firing rates of 6 neurons were further excited by homolateral EA, with a significant increase of the firing rates (P < 0.05); all inhibitory gastric-related neurons in NTS were excited by EA. The inhibition rate of homolateral EA was significantly increased in comparison with contralateral EA in gastric-related neurons of SDH (P < 0.05). There was no significant difference between homolateral and contralateral EA in gastric-related neurons of NTS. EA at ST36 changes the firing rate of gastric-related neurons in SDH and NTS. However, there are some differences in responsive mode in these neurons. The existence of these differences could be one of the physiological foundations of diversity and complexity in EA effects.

Strong Manual Acupuncture Manipulation Could Better Inhibit Spike Frequency of the Dorsal Horn Neurons in Rats with Acute Visceral Nociception

“…And the spike frequency also could be regulated by MA at ST36. This conclusion is consistent with previous study [ 23 ].…”

“…Amongst them, 35 (40%) were excited and 14 (16%) were inhibited by GD ( Figure 3 ). They showed more than 15% change (change rate = the number of spikes after stimulation/the number of spikes before stimulation) in the number of spikes and were defined as gastric-related neurons [ 23 ]. In the experiment, we focused on the excitatory gastric-related neurons.…”

“…Commonly labeled neurons were found in thoracic, lumbar, and sacral spinal segments [ 28 ]. Electrophysiological studies showed that noxious visceral and somatic afferent information separately from the gastrointestinal and ST36 could converge in the neurons of SDH [ 2 , 23 , 29 , 30 ]. These findings revealed a potential mechanism for ST36 treating visceral diseases.…”

“…Extracellular recordings of the activity of single WDR neurons in SDH with receptive fields (RFs) located on ST36 were obtained with a glass microelectrode (impedance: 10~15 MΩ; the tip of the microelectrode: 1-2 μ m (A-M Systems Co.)) filled with 2% Pontamine Sky Blue in 0.5 mol/L sodium acetate. Recording electrodes were lowered into the spinal cord using an electronic micromanipulator (MO-10, Narishige, Japan) in 1 μ m steps: 0.5–1.2 mm lateral to the midline in the right side of spinal cord and 0.3–1.3 mm from the dorsal surface [ 23 ]. Recordings were made only from single neurons whose amplitude could be easily discriminated.…”

Challenging Case in Clinical Practice: Acupuncture and Autonomically Mediated Pain

“…1 The addition of GV20 enhanced parasympathetic properties, 16 as did ST36. 17,18 Treatment of sympathetically mediated pain could have been via acupuncture of Bladder or Huato-Jiaji points. Preganglionic sympathetic neurons mediating sympathetic outflow to the upper limb are located in the lateral autonomic horn of the spinal cord between the levels T5 and T9.…”