Functional alterations in gut contractility after connexin36 ablation and evidence for gap junctions forming electrical synapses between nitrergic enteric neurons

FEBS Lett. 2014 Apr 17;588(8):1480-90. doi: 10.1016/j.febslet.2014.02.002. Epub 2014 Feb 15.

Abstract

Neurons in the enteric nervous system utilize numerous neurotransmitters to orchestrate rhythmic gut smooth muscle contractions. We examined whether electrical synapses formed by gap junctions containing connexin36 also contribute to communication between enteric neurons in mouse colon. Spontaneous contractility properties and responses to electrical field stimulation and cholinergic agonist were altered in gut from connexin36 knockout vs. wild-type mice. Immunofluorescence revealed punctate labelling of connexin36 that was localized at appositions between somata of enteric neurons immunopositive for the enzyme nitric oxide synthase. There is indication for a possible functional role of gap junctions between inhibitory nitrergic enteric neurons.

Keywords: Connexin36 knockout; EGFP reporter; Gastrointestinal system; Immunofluorescence; Nitric oxide; Nitric oxide synthase.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cholinergic Agonists / pharmacology
  • Colon / innervation
  • Colon / physiology*
  • Connexins / genetics
  • Connexins / metabolism*
  • Electrical Synapses / metabolism*
  • Electrical Synapses / physiology
  • Enteric Nervous System / cytology
  • Enteric Nervous System / metabolism
  • Enteric Nervous System / physiology*
  • Gene Deletion
  • Mice
  • Mice, Inbred C57BL
  • Muscle Contraction*
  • Muscle, Smooth / innervation
  • Muscle, Smooth / physiology
  • Neurons / drug effects
  • Neurons / metabolism*
  • Neurons / physiology
  • Nitric Oxide Synthase Type III / genetics
  • Nitric Oxide Synthase Type III / metabolism
  • Rats
  • Rats, Sprague-Dawley

Substances

  • Cholinergic Agonists
  • Connexins
  • connexin 36
  • Nitric Oxide Synthase Type III