Oropharyngeal dysphagia (OD) affects older and neurological patients, causing malnutrition and dehydration and increasing the risk for aspiration pneumonia. There is evidence that sensory deficits in those populations are closely related to swallowing disorders, and several research groups are developing new therapies based on sensory stimulation of this area. More information on the sensory innervation participating in the swallow response is needed to better understand the pathophysiology of OD and to develop new treatments. This review focuses on the sensory innervation of the human oropharynx and larynx in healthy people compared with patients with swallowing disorders in order to unravel the abnormalities that may lead to the loss of sensitivity in patients with OD. We also hypothesize the pathway through which active sensory-enhancement treatments may elicit their therapeutic effect on patients with swallowing dysfunctions. As far as we know, this is the first time a review covers the anatomy, histology, ultrastructure, and molecular biology of the sensory innervation of the swallowing function.

TRPV1 and TRPA1 are widely expressed in the human oropharynx with two distinct patterns. Our study further confirms that TRPV1/A1 receptors are promising therapeutic targets to develop active treatments for OD patients.

TRPM8 and ASIC3 are found on submucosal sensory nerves in the human oropharynx. Our study lays the basis to use oropharyngeal TRPM8 and ASIC3 receptors as therapeutic targets to develop new active pharmacological treatments for OD patients.