Role of pulmonary afferent inputs in vocal on-switch in the cat.
The purpose of this paper is to elucidate the possible role of pulmonary afferent inputs in triggering inspiratory-vocal (I-V) and Vocal-inspiratory (V-I) transitions during periaqueductal gray (PAG)-induced vocalization. Under ketamine anesthesia, we investigated the effects of changes in pulmonary afferent inputs on the PAG-induced vocal motor pattern by transection and electrical stimulation of the cervical vagus nerve in non-paralyzed cats and by lung inflation and deflation in paralyzed cats. After bilateral vagotomy, PAG stimulation induced apneusis; strong suppression of the I-V transition disrupted the vocal rhythmicity. Electrical stimulation of the central end of the cut vagus nerve during PAG stimulation immediately caused an I-V transition. In paralyzed cats during the withholding of lung inflation, the I-V transition was also suppressed during PAG stimulation. Lung inflation during PAG stimulation caused a phase switch from inspiration to fictive vocalization, i.e. I-V transition. In contrast, this fictive vocal phase maintained by lung inflation was terminated by lung deflation, i.e. V-I transition. These findings suggest that pulmonary vagal afferent feedback plays an important role in triggering and terminating vocalization.
Nakazawa
K
K
Department of Otolaryngology, School of Medicine, Chiba University, Japan.
Shiba
K
K
Satoh
I
I
Yoshida
K
K
Nakajima
Y
Y
Konno
A
A
D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D002415:Cats; D005260:Female; D008297:Male; D012143:Respiratory Physiological Phenomena; D014628:Vagotomy; D014828:Vocalization, Animal / Q000502:physiology*