Figure 6 - Model showing the marked delay in onset of distal esophageal contractions during peristalsis.

With the initial stimulation, be it swallowing or distention, there is a short-lived hyperpolarization that is slightly longer in more aboral region of the esophagus. Intrinsic descending inhibitory neurons can then be continuously reactivated by contraction or bolus distention as it migrates down the esophagus.