Respiratory activation of the facial nerve and alar muscles in anaesthetized dogs.

Abstract

SUMMARY1. Comparisons were made of the activities of the dorsal buccal branch (d.b.b.) of the facial nerve which innervates the alae nasi and of the alar muscles themselves (alae nasi) with the activity ofthe phrenic nerve in eight anaesthetized, spontaneously breathing dogs during hypercapnia, end-expiratory airway occlusion, and chest wall compression, before and after vagotomy. Nerve and muscle activities were recorded from bipolar cuff or wire electrodes respectively and processed by a moving average technique.2. Peak facial d.b.b., alae nasi, and phrenic activity all increased linearly with hypercapnia.3. Airway occlusion prolonged the duration of phrenic as well as facial d.b.b. and alae nasi activity. A comparison of electrical activity during unoccluded and occluded inspirations indicated a facilitation of phrenic activity but an inhibition of both facial d.b.b. and alae nasi activities associated with volume feed-back. These volume-related feed-back effects were abolished by vagotomy. 4. After vagotomy, peak facial d.b.b., alae nasi and phrenic activities increased during lower chest wall compression and decreased with upper chest wall compression when compared to the preceding control breath.5. Alae nasi and facial nerve activities, like that of the phrenic nerve, respond to respiratory chemical and reflex influences.

Differential control of the inspiratory intercostal muscles during airway occlusion in the dog.

“…Volume-related vagal afferents from the lungs modulate the motor discharges to the diaphragm, and removing these influences by blocking the vagal nerves or by occluding the airway for a single breath in anaesthetized animals has recently been reported to produce inhibition of diaphragmatic activity. Such a vagal facilitatory effect of phasic volume feedback on the diaphragm has been shown in the cat (Bartoli, Cross, Guz, Huszczuk & Jefferies, 1975;Di Marco, von Euler, Romaniuk & Yamamoto, 1981) and in the dog (van Lunteren et al 1984;Strohl, 1985). To the extent that the inhibition of parasternal intercostal activity during airway occlusion was known not to be caused by tendon organs, we thus speculated that it was related to the removal of vagal afferent inputs.…”

“…Occluded inspiration, however, elicited different responses in the three muscles studied (see Results). Therefore, in each animal, the traces of integrated EMG signals during each occluded breath were subsequently superimposed on the traces obtained during the immediately preceding unoccluded breath (Younes, Iscoe & Milic-Emili, 1975;van Lunteren, Strohl, Parker, Bruce, van de Graaf & Cherniack, 1984;Strohl, 1985). As shown in Fig.…”

Identification of a Novel Form of Noradrenergic-Dependent Respiratory Motor Plasticity Triggered by Vagal Feedback

“…Obstructive apneas not only cause hypoxemia (Guilleminault and Abad, 2004), they also affect mechanical vagal afferent feedback (van Lunteren et al, 1984;Strohl, 1985;Milsom, 1990;Bailey and Fregosi, 2006). The following set of experiments was therefore designed to determine how each of these variables contributes to apnea-induced LTF.…”

Uncoupling of upper airway motor activity from phrenic bursting by positive end-expired pressure in the rat

“…The compliance and geometry of this region are influenced by a number of skeletal muscles. Among them are the alae nasi, tongue, and laryngeal muscles, which are innervated by the facial (FN), hypoglossal (HN) and superior (SLN), and recurrent laryngeal nerves (RLN), respectively (1,26,41).Many studies have shown that the inspiratory (I) discharge of the HN precedes the phrenic I burst (5,6,13,17,23,33). This preinspiratory (Pre-I) activity has been suggested to benefit UAW patency by dilating and stiffening the UAW before the onset of I airflow (30).…”

“…The compliance and geometry of this region are influenced by a number of skeletal muscles. Among them are the alae nasi, tongue, and laryngeal muscles, which are innervated by the facial (FN), hypoglossal (HN) and superior (SLN), and recurrent laryngeal nerves (RLN), respectively (1,26,41).…”