Qi-Jian Sun

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Substance P (SP), tyrosine hydroxylase (TH) and serotonin inputs onto laryngeal motoneurons (LMNs) are known to exist, but the distribution of their terminals in the caudal nucleus ambiguus (NA), remains unclear. Using immunofluorescence and confocal microscopy, we assessed simultaneously the distribution of SP, TH, serotonin and synaptophysin(More)
Serotonergic neurons are distributed widely throughout the central nervous system and exert a tonic influence on a range of activities in relation to the sleep-wake cycle. Previous morphologic and functional studies have indicated a role for serotonin in control of laryngeal motoneurons. In the present study, we used a combination of intracellular(More)
OBJECTIVES/HYPOTHESIS The objective was to demonstrate close appositions between serotonin-immunoreactive boutons and laryngeal constrictor (LCon) motoneurons in Sprague-Dawley rats. STUDY DESIGN Animal experimental. METHODS LCon motoneurons were identified functionally by their antidromic responses to stimulation of the recurrent laryngeal nerve and(More)
OBJECTIVES Electromyographic studies of the laryngeal adductor reflex, glottal closure occurring in response to laryngeal stimulation, have demonstrated an early ipsilateral response (R1) and a late bilateral response (R2). To better define the physiologic properties of these responses, we recorded responses from expiratory laryngeal motoneurons (ELMs) in(More)
A striking effect of stimulating the superior laryngeal nerve (SLN) is its ability to inhibit central inspiratory activity (cause ‘phrenic apnoea'), but the mechanism underlying this inhibition remains unclear. Here we demonstrate, by stimulating the SLN at varying frequencies, that the evoked non-respiratory burst activity recorded from expiratory(More)
The intrinsic laryngeal muscles are differentially modulated during respiration as well as other states and behaviors such as hypocapnia and sleep. Previous anatomical and pharmacological studies indicate a role for acetylcholine at the level of the nucleus ambiguus in the modulation of laryngeal motoneuron (LMN) activity. The present study investigated the(More)
Laryngeal constrictor motoneurons (LCMN) are activated during post-inspiration and act to slow expiratory airflow. However, little is known about how this phasic activity is generated. Here, we investigated the electrophysiological responses of identified LCMN to local application of GABA and bicuculline methiodide (BIC) in 14 anaesthetised Sprague-Dawley(More)
Substance P terminals have previously been demonstrated around retrogradely labelled posterior cricoarytenoid (PCA) motoneurons, but little is known regarding substance P inputs to other functionally identified laryngeal motoneurons. In the present study, we determined the number and distribution of close appositions between substance P immunoreactive(More)
BACKGROUND The effect of angiotensin II type I receptor (AT1R) inhibition on the pattern of reflex sympathetic nerve activity (SNA) to multiple target organs in the Lewis polycystic kidney (LPK) rat model of chronic kidney disease was determined. METHODS Mean arterial pressure (MAP), splanchnic SNA (sSNA), renal SNA (rSNA) and lumbar SNA (lSNA) were(More)
Swallowing and breathing utilize common muscles and an anatomical passage: the pharynx. The risk of aspiration of ingested material is minimized not only by the laryngeal adduction of the vocal folds and laryngeal elevation but also by the precise coordination of swallows with breathing. Namely, swallows: (1) are preferentially initiated in the(More)