Functional MRI of oropharyngeal air-pulse stimulation.

Although the posterior oral cavity and oropharynx play a major role in swallowing, their central representation is poorly understood. High-field functional magnetic resonance imaging of the brain was used to study the central processing of brief air-pulses, delivered to the peritonsillar region of the lateral oropharynx, in six healthy adults. Bilateral air-pulse stimulation was associated with the activation of a bilateral network including the primary somatosensory cortex and the thalamus, classic motor areas (primary motor cortex, supplementary motor area, cingulate motor areas), and polymodal areas (including the insula and frontal cortex). These results suggest that oropharyngeal stimulation can activate a bilaterally distributed cortical network that overlaps cortical regions previously implicated in oral and pharyngeal sensorimotor functions such as tongue movement, mastication, and swallowing. The present study also demonstrates the utility of air-pulse stimulation in investigating oropharyngeal sensorimotor processing in functional brain imaging experiments.