Vagal innervation of the air sacs in a songbird, Taenopygia guttata.
The air sacs of birds are thin-walled chambers connected to the lung that act as bellows in the ventilatory mechanism. Physiological evidence exists to suggest that they may contain receptors that are innervated by the vagus nerve, but no morphological study has examined the vagal innervation of these putative structures. To do this, we injected the cervical vagus nerve with choleragenoid and examined the innervation of the air sacs using light and confocal microscopy. We identified vagally innervated structures in the air sac wall that resemble the neuroepithelial bodies (NEBs) described in the airways of many vertebrates. Although NEBs have been proposed to have a dual chemoreceptive and mechanoreceptive role, their specific function in the air sacs of birds remains unclear.
Kubke
M Fabiana
MF
Department of Anatomy with Radiology, Faculty of Medical and Health Sciences, The University of Auckland, New Zealand. f.kubke@auckland.ac.nz
Ross
Jacqueline M
JM
Wild
J Martin
JM
D000400:Air Sacs / Q000294:innervation*; D000818:Animals; D007150:Immunohistochemistry / Q000379:methods; D018613:Microscopy, Confocal; D020308:Songbirds / Q000033:anatomy & histology*; D014630:Vagus Nerve / Q000033:anatomy & histology*