Histochemistry and Cell Biology

, Volume 125, Issue 4, pp 377–395

Vesicular glutamate transporter 1 immunoreactivity in extrinsic and intrinsic innervation of the rat esophagus

Original paper

DOI: 10.1007/s00418-005-0083-z

Cite this article as:
Ewald, P., Neuhuber, W. & Raab, M. Histochem Cell Biol (2006) 125: 377. doi:10.1007/s00418-005-0083-z

Abstract

Encouraged by the recent finding of vesicular glutamate transporter 2 (VGLUT2) immunoreactivity (-ir) in intraganglionic laminar endings (IGLEs) of the rat esophagus, we investigated also the distribution and co-localization patterns of VGLUT1. Confocal imaging revealed substantial co-localization of VGLUT1-ir with selective markers of IGLEs, i.e., calretinin and VGLUT2, indicating that IGLEs contain both VGLUT1 and VGLUT2 within their synaptic vesicles. Besides IGLEs, we found VGLUT1-ir in both cholinergic and nitrergic myenteric neuronal cell bodies, in fibers of the muscularis mucosae, and in esophageal motor endplates. Skeletal neuromuscular junctions, in contrast, showed no VGLUT1-ir. We also tested for probable co-localization of VGLUT1-ir with markers of extrinsic and intrinsic esophageal innervation and glia. Within the myenteric neuropil we found, besides co-localization of VGLUT1 and substance P, no further co-localization of VGLUT1-ir with any of these markers. In the muscularis mucosae some VGLUT1-ir fibers were shown to contain neuronal nitric oxide synthase (nNOS)-ir. VGLUT1-ir in esophageal motor endplates was partly co-localized with vesicular acetylcholine transporter (VAChT)/choline acetyltransferase (ChAT)-ir, but VGLUT1-ir was also demonstrated in separately terminating fibers at motor endplates co-localized neither with ChAT/VAChT-ir nor with nNOS-ir, suggesting a hitherto unknown glutamatergic enteric co-innervation. Thus, VGLUT1-ir was found in extrinsic as well as intrinsic innervation of the rat esophagus.

Keywords

Intraganglionic laminar endings (IGLEs) Motor endplates Enteric co-innervation Substance P Visceral afferents Enteric nervous system Skeletal muscle 

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Department of Anatomy IUniversity of Erlangen-NurembergErlangenGermany
  2. 2.Institut für AnatomieLehrstuhl IErlangenGermany

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