Diversity of neurogenic smooth muscle electrical rhythmicity in mouse proximal colon

Nick J. Spencer, Lee Travis, Lukasz Wiklendt, Timothy J. Hibberd, Marcello Costa, Phil Dinning, Hongzhen Hu

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

The mechanisms underlying electrical rhythmicity in smooth muscle of the proximal colon are incompletely understood. Our aim was to identify patterns of electrical rhythmicity in smooth muscle of the proximal region of isolated whole mouse colon and characterize their mechanisms of origin. Two independent extracellular recording electrodes were used to record the patterns of electrical activity in smooth muscle of the proximal region of whole isolated mouse colon. Cross-correlation analysis was used to quantify spatial coordination of these electrical activities over increasing electrode separation distances. Four distinct neurogenic patterns of electrical rhythmicity were identified in smooth muscle of the proximal colon, three of which have not been identified and consisted of bursts of rhythmic action potentials at 1–2 Hz that were abolished by hexamethonium. These neurogenic patterns of electrical rhythmicity in smooth muscle were spatially and temporally synchronized over large separation distances (≥2 mm rosto-caudal axis). Myogenic slow waves could be recorded from the same preparations, but they showed poor spatial and temporal coordination over even short distances (≤1 mm rostro-caudal axis). It is not commonly thought that electrical rhythmicity in gastrointestinal smooth muscle is dependent upon the enteric nervous system. Here, we identified neurogenic patterns of electrical rhythmicity in smooth muscle of the proximal region of isolated mouse colon, which are dependent on synaptic transmission in the enteric nervous system. If the whole colon is studied in vitro, recordings can preserve novel neurogenic patterns of electrical rhythmicity in smooth muscle. NEW & NOTEWORTHY Previously, it has not often been thought that electrical rhythmicity in smooth muscle of the gastrointestinal tract is dependent upon the enteric nervous system. We identified patterns of electrical rhythmicity in smooth muscle of the mouse proximal colon that were abolished by hexamethonium and involved the temporal synchronization of smooth muscle membrane potential over large spatial fields. We reveal different patterns of electrical rhythmicity in colonic smooth muscle that are dependent on the ENS.

Original languageEnglish
Pages (from-to)G244-G253
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume318
Issue number2
DOIs
StatePublished - Feb 2020

Keywords

  • Autonomic
  • Colon
  • Enteric nervous system
  • Peristalsis
  • Smooth muscle

Fingerprint Dive into the research topics of 'Diversity of neurogenic smooth muscle electrical rhythmicity in mouse proximal colon'. Together they form a unique fingerprint.

  • Cite this