Electron microscopic and autoradiographic analysis of the distribution of the vagus nerve in the ferret stomach

Abstract

In this study, tritiated leucine was injected into the vagal dorsal motor nucleus after acute and chronic partial vagotomy. The method of sampling of the stomach, application of % 2 test and the analysis of the electron microscopic autoradiographs revealed that the distribution of silver grains over the axon profiles were uniformly distributed over the body and pyloric areas of the stomach. Also a % test showed that the number of grains is independent of the area chosen. Statistical analysis of the distribution of the dorsal and ventral vagus nerves confirmed that the ventral surface of the body of the stomach is innervated by the ventral vagus nerve while the dorsal surface of the body and pylorus is innervated by the dorsal vagus nerve and the ventral surface of the pylorus is innervated by both ventral and dorsal vagus nerves. Statistical analysis of the redistribution of the dorsal and ventral vagus nerves after chronic partial vagotomy showed a significant drop in the number of labeled nerve fibers in the areas of the dorsal surface of the body of the stomach, because the ventral vagus nerve had spread to supply just a small area on the dorsal surface of the stomach. On the other hand, the dorsal vagus nerve spread to supply all areas of the ventral surface of the stomach. However, the degree of territorial had spread in the dorsal and ventral vagus nerves may be correlated with secretomotor changes, especially if the ventral nerve is predominantly secretomotor. The statistical analysis of the results could also explain that the functional loss of gastric motility after acute partial vagotomy and the gastric recovery after chronic partial vagotomy. Furthermore, the results may add more information on each vagus nerve which is important in vagotomy treatment of peptic ulceration, so the recent operation of dorsal truncal vagotomy and seromyotomy which is used in treatment of chronic duodenal ulcer is explained by the spread of dorsal vagus nerve to supply all areas of the stomach after chronic ventral vagotomy.