Cortical processing of esophageal sensation is related to the representation of swallowing

The esophagus plays a major role in the act of swallowing. The aim of the present investigation was to apply whole-head magnetoencephalography in order to study the cortical processing of esophageal sensation in healthy humans in whom the cortical representation of swallowing had been established previously. The proximal esophagus was stimulated in nine participants by intermittent 5 ml water infusion. Submental EMG recording was used to identify trials, which were contaminated by subsequent swallowing. Esophageal stimulation led to changes in rhythmic activity of the brain that were localized in the left lateral primary sensorimotor cortex. The pattern of cortical activation showed the same hemispheric lateralization as that of volitional swallowing, however, being localized more lateral. The close anatomical vicinity of these two functions points to an important physiological link between the cortical processing of esophageal sensation and the cortical control of swallowing. (c) 2005 Lippincott Williams & Wilkins.