The Spatial Relationship and Surface Projection of Canine Sciatic Nerve and Sacrotuberous Ligament: A Perineal Hernia Repair Perspective.

Sciatic nerve entrapment can occur as post-operative complication of perineal hernia repair when sacrotuberous ligament is incorporated during hernia deficit closure. This results in sciatic sensory loss and paralysis of the hind leg. This study investigated the spatial relationship of sciatic nerve and sacrotuberous ligament and their surface topographic projection of 68 cadavers (29 Beagles and 39 Taiwanese mongrels) with various heights (25-56 cm). By gross dissection, the sacrotuberous ligament and sciatic nerve were exposed and their distance in between was measured along four parts (A, B, C, D) of sacrotuberous ligament. The present study revealed that the C was the section of sacrotuberous ligament where the sciatic nerve and the sacrotuberous ligament are closest to each other. Furthermore, a positive correlation was observed between C and height of the dogs. From the present study, we found that the C in smaller dogs has the shortest distance between the sciatic nerve and the sacrotuberous ligament, and thus the most vulnerable to sciatic nerve entrapment, and needs to be avoided or approached cautiously during perineal hernia repair.

Neuronal Activity Stimulated by Liquid Substrates Injection at Zusanli (ST36) Acupoint: The Possible Mechanism of Aquapuncture.

Aquapuncture is a modified acupuncture technique and it is generally accepted that it has a greater therapeutic effect than acupuncture because of the combination of the acupoint stimulation and the pharmacological effect of the drugs. However, to date, the mechanisms underlying the effects of aquapuncture remain unclear. We hypothesized that both the change in the local spatial configuration and the substrate stimulation of aquapuncture would activate neuronal signaling. Thus, bee venom, normal saline, and vitamins B1 and B12 were injected into a Zusanli (ST36) acupoint as substrate of aquapuncture, whereas a dry needle was inserted into ST36 as a control. After aquapuncture, activated neurons expressing Fos protein were mainly observed in the dorsal horn of the spinal cord in lumbar segments L3-5, with the distribution nearly identical among all groups. However, the bee venom injection induced significantly more Fos-expressing neurons than the other substrates. Based on these data, we suggest that changes in the spatial configuration of the acupoint activate neuronal signaling and that bee venom may further strengthen this neuronal activity. In conclusion, the mechanisms for the effects of aquapuncture appear to be the spatial configuration changes occurring within the acupoint and the ability of injected substrates to stimulate neuronal activity.

The Possible Neuronal Mechanism of Acupuncture: Morphological Evidence of the Neuronal Connection between Groin A-Shi Point and Uterus.

Somatovisceral reflex suggested that the somatic stimulation could affect visceral function like acupuncture which treats diseases by stimulating acupoints. The neuronal connection between somatic point and visceral organ was not clear. Uterine pain referred to the groin region has long been recognized clinically. Wesselmann, using neurogenic plasma extravasation method, showed that uterine pain was referred to the groin region through a neuronal mechanism (Wesselmann and Lai 1997). This connection could be considered through the somatovisceral reflex pathway. However, the relay center of this pathway is still not clearly identified. In the present study, bee venom was injected in the groin region to induce central Fos expression to map the sensory innervation of groin region. Pseudorabies virus (PrV), a transneuronal tracer, was injected in the uterus to identify the higher motor control of the uterus. Immunohistochemistry staining revealed the Fos expression and PrV-infected double-labeled neurons in the nucleus of solitary tract (NTS), the dorsal motor nucleus of vagus (DMX), and the paraventricular hypothalamic nucleus (PVN). These results suggest a somatoparasympathetic neuronal connection (groin-spinal dorsal horn-NTS/DMX-uterus) and a somatosympathetic neuronal connection (groin-spinal dorsal horn-NTS-PVN-uterus). These two neuronal connections could be the prerequisites to the neuronal basis of the somatovisceral reflex and also the neuronal mechanism of acupuncture.