“…Thus, induced cough in humans is preceded by an initial urge to cough (Davenport et al, 2007;Dicpinigaitis et al, 2012), an observation that is likely the clinical manifestation of the physiologic evidence that cough initiation requires sustained, high-frequency vagal afferent nerve activation in animals (Canning, 2009;Canning and Mori, 2011). Consistent with the involvement of NMDA receptors in cough, both ketamine and dextromethorphan have been reported to suppress cough in patients (Yeh et al, 2007;Faruqi et al, 2014). Moreover, in preclinical studies, dextromethorphan and other NMDA receptor/channel blockers prevent evoked coughing in dogs, cats, rabbits, guinea pigs, and rats (Kamei et al, 1989;Dicpinigaitis et al, 2014a;reviewed in Canning, 2009, andCanning andMori, 2011).…”