Faculty Collaboration Database

The pharyngeal phase of swallowing controls deglutitive inhibition. Am J Physiol Regul Integr Comp Physiol 2025 Nov 01;329(5):R784-R795

Date

10/15/2025

Pubmed ID

41087037

DOI

10.1152/ajpregu.00136.2025

Scopus ID

2-s2.0-105021143017 (requires institutional sign-in at Scopus site)

Abstract

The goal of this study was to determine which phase of swallowing causes deglutitive inhibition (DI). DI is inhibition of ongoing peristalsis by a new swallow. Pharynx and esophagus of decerebrate cats (n = 25) were instrumented to record esophageal peristalsis. Injecting saline into pharynx or esophagus activated primary (pharyngeal and esophageal phases) peristalsis repeatedly and randomly, or secondary (esophageal phase) peristalsis once, respectively. When a new primary peristalsis occurred during ongoing primary peristalsis, the occurrence of ongoing esophageal peristalsis was blocked when it was 1-10 cm from upper esophageal sphincter, then secondary peristalsis occurred 1.3 ± 0.1 s (n = 22) later at same location. This esophageal blockade occurred almost simultaneously [0.15 ± 0.01 s (n = 17) before] with activation of thyropharyngeus activation during the new pharyngeal phase. When ongoing primary peristalsis was at or below 13 cm from upper esophageal sphincter, the magnitude of primary esophageal peristalsis significantly decreased (102 ± 14 vs. 49 ± 8 mm Hg, n = 8, P < 0.01) during the new pharyngeal phase, but peristaltic progression was not altered. DI had same effects on secondary peristalsis. DI of ongoing peristalsis in distal esophagus occurred before or without new esophageal phase in every case (21 cases, n = 9), except one. DI is central inhibition of ongoing esophageal phase of swallowing by the new pharyngeal phase as short-term cessation of striated muscle peristalsis and longer-term reduction in smooth muscle peristaltic magnitude. Esophageal or oral phase of swallowing does not cause DI.NEW & NOTEWORTHY Deglutitive inhibition is caused by central inhibition of ongoing esophageal phase of swallowing during the new pharyngeal phase by short-term cessation of striated muscle peristalsis and longer-term reduction in smooth muscle peristaltic magnitude. The esophageal or oral phase of swallowing does not cause deglutitive inhibition. Deglutitive inhibition is pharyngeal phase central inhibition of the esophageal phase of swallowing.

Author List

Lang IM, Medda BK, Edeani F, Shaker R

Authors

Francis Edeani MBBS Associate Professor in the Medicine department at Medical College of Wisconsin
Bidyut K. Medda PhD Associate Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Cats
Deglutition
Esophagus
Female
Male
Peristalsis
Pharynx
Swallows