RE-EXAMINATION OF CENTRALLY-INDUCED COUGH IN CATS USING A MICRO-STIMULATION TECHNIQUE

摘要

References(17) Cited-By(13) Traditionally, the central structure for producing a cough response by electrical stimulation has been called the cough center (1). In 1948, Borison (2) stimulated the dorsolateral region of the medulla oblongata in the cat and induced a spasmodic respiratory response very similar to coughing, sneezing and retching. Chakravarty et al. (3) induced the same response by stimulating the same area and indicated the application to evaluation of antitussive drugs. Recently, Kasé and his associates (4) explored a more caudal portion of the medulla and found a region capable of inducing cough-like response at the level of the obex, and the response induced appeared to be a little different in nature from the gasp-like responses observed by Borison. In these studies relatively large electrodes and high voltage stimuli (1.2-8.0 V) were used (5-7). Methodological limitations in these studies might have misled to assess a wider boundary as an area of the cough center. In the present article we have examined the area in the medulla by using a stimulating electrode of smaller size and a minute intensity of stimulus to induce cough-like response. The results indicate that the area, in which the cough-like response is produced by electrical stimulation, is confined distinctly to a certain anatomical structure of the medulla, i.e., the nucleus tractus solitarius.