STUDIES ON THE VOMITING CENTER. THE LOCATION OF THE RETCHING POINTS IN THE MEDULLA AND PONS

Abstract

During the experiments on the motor center of the stomach in the medulla and pons, the different types of the emetic action were observed in the dog. The monopolar tungsten wire (diameter 25 microns) was used for the stimulating electrode. The stimulated areas were determined by the histolo-gical examination.1. The retching was followed by the change of the systemic blood pressure (rise or fall) and the increase or decrease of the movements of the stomach and distal colon, but the correlation between the retching and the other autonomic reactions was not determined.2. The retching was induced in the vagotomized dog and in the spinal dog which was transected between the cervical and the thoracic region.3. The retching was induced both in the anesthetized dog and non-anesthetized dog.4. Fourty-five retching points were obtained in the medulla oblongata. They were found in the Nucl. dorsolateralis n. vagi, Nucl. dorsomedialis n. vagi, Nucl. tractus solitarii medialis, -inferior, -lateralis, Tractus solitarius, Formatia reticularis, Fibrae arcuatae internae and Nucl. intercalatus.5. Only three retching points were obtained in the pons. They were found in the Nucl. vestibularislateralis, Tractus rubrospinalis and Fibrae n. vagi.