Neurons in the NTS of Rat Response to Gastric Distention Stimulation and Acupuncture at Body Surface Points

The nucleus of the solitary tract (NTS) is a primary center, not only for receiving visceral afferents, but also for somatic afferents. Previous experiments demonstrated that NTS might be a primary afferent center for connecting the Stomach Meridian (ST Medirian) and the Stomach. In this study, an extracellular recording method was used to analyze the firing neurons. The variety of NTS' neurons' responses to gastric distention (GD) and different body surface points were compared. In 52 rats, 104 firing neurons of NTS were recorded, in which there were 47 GD related neurons. For the 47 GD related neurons, there were 33 neurons responsive to acupuncture at Sibai (ST 2, belonging to ST Meridian). Therefore, in the 47 GD related neurons, the response neuron occurring rate (RNOR) for acupuncture at ST 2 was 70.21%. Meanwhile in the 47 GD related neurons, when acupuncture was performed at Quanliao (SI 18, belonging to Small Intestine Meridian) and non-acupoint respectively, there were 18 and 17 firing neurons, and the RNOR were 38.30% and 36.17% respectively. The experiment demonstrated that there were some varieties in the response of NTS neurons to GD stimuli and acupuncture at different body surface points, which suggested that the ST Meridian was more intimately linked to the Stomach and that the different acupoints do have some specificity.