Differential respiratory control of the upper airway and diaphragm muscles induced by XXXX receptor ligands.

@entity10097 @entity10463 @entity27 @entity5019 @entity30 @entity7405 @entity750 @entity10098 @entity35 @entity590
BACKGROUND: @entity750 ( @entity750 ) has a role in respiratory function and dysfunction. Although @entity750 affects respiratory drive to both phrenic and cranial motoneurons, relatively little is known about the role of @entity750 receptor subtypes in the control of upper airway muscle (UAM) respiratory activity. MATERIALS AND METHODS: Here, we performed central injections of @entity10463 agonist ( @entity10097 ) or antagonist ( @entity10098 ) in anesthetized @entity35 and analyzed changes in the electromyographic activity of several UAM and other cardiorespiratory parameters. We also compared the pattern of @entity5019 expression induced after central injection of a control solution or @entity10097 . RESULTS: Results showed that @entity10097 induced a robust increase in UAM activity, associated with either @entity7405 under @entity590 or bradypnea under liquid anesthesia. Injection of @entity10098 switched off UAM respiratory activity and led to bradypnea, suggesting a tonic excitatory role of endogenous @entity10463 receptor activation. Co-injection of the agonist and the antagonist blocked the effects produced by each drug alone. Besides drug-induced changes in respiratory frequency, only slight increases in surface of diaphragm bursts were observed. Significant increases in @entity5019 expression after @entity10463 receptor activation were seen in the nucleus tractus solitarius, nucleus raphe pallidus, @entity30 , retrotrapezoid nucleus, lateral parabrachial, and K  lliker-Fuse nuclei. This restricted pattern of @entity5019 expression likely identified the neural substrate responsible for the enhancement of UAM respiratory activity observed after @entity10097 injection. CONCLUSIONS: These findings suggest an important role for the @entity10463 receptors in the neural control of upper airway patency and may be relevant to counteract pharyngeal atonia during @entity27 .
