Depression of diaphragmatic and external intercostal muscle activities elicited by stimulation of midpontine dorsal tegmentum in decerebrate cats.
This paper describes the inhibitory influences on external intercostal muscle activity and diaphragmatic activity, evoked by stimulation of the dorsal tegmental field (DTF) of the pons in decerebrate cats. Stimulation of the DTF along the midline decreased both the diaphragmatic and the external intercostal activities. However, the inhibitory influences on the above two kinds of respiratory muscle activities were different in nature. Diaphragmatic activity, once suppressed by stimulation, recovered in spite of the continuation of stimulation. In contrast, DTF stimulation depressed tonic discharges of external intercostal muscle, and the depressed or abolished tonic discharges did not resume even after termination of stimulation. Rhythmic external intercostal muscle activity, synchronized with diaphragmatic activity, was also suppressed by DTF stimulation and the suppressed rhythmic activity seemed difficult to recover during stimulation, compared with the recovery process of the diaphragmatic activity.
Kawahara
K
K
Department of Information Engineering, Yamagata University, Japan.
Nakazono
Y
Y
Miyamoto
Y
Y
D000818:Animals; D002415:Cats; D003964:Diaphragm / Q000294:innervation / Q000502:physiology*; D004525:Efferent Pathways / Q000502:physiology; D007366:Intercostal Muscles / Q000294:innervation / Q000502:physiology*; D011149:Pons / Q000502:physiology*; D012119:Respiration