In mammals including the human beings, the neural control of airway smooth muscles is dominated by medullary airway vagal preganglionic neurons (AVPNs), especially those located in the external formation of the nucleus ambiguus (eNA).The AVPNs are intrinsically silent, and their activity relies completely on their synaptic inputs.The AVPNs receive excitatory glutamatergic and inhibitory GABAergic and glycinergie inputs.During the inspiratory phase, the majority of the AVPNs are activated due to the burst of the excitatory inputs (inspiratory-activated AVPNs); and the minority of them are inhibited due to the burst of the inhibitory inputs (inspiratory-inhibited AVPNs).Ample evidence has suggested that the AVPNs are physiologically regulated by central adrenergic/noradrenergic mechanisms; and dysfunctional adrenergic/noradrenergic control of the AVPNs has also been indicated to be involved in the pathogenesis of some important airway disorders.However, at neuronal and synaptic levels, the mechanisms involved in the adrenergic/noradrenergic control of the AVPNs are poorly understood.