Neurochemical characterization of extrinsic nerves in myenteric ganglia of the guinea pig distal colon

Abstract

Extrinsic nerves to the gut influence the absorption of water and electrolytes and expulsion of waste contents, largely via regulation of enteric neural circuits; they also contribute to the control of blood 45

Sensory innervation of the guinea pig colon and rectum compared using retrograde tracing and immunohistochemistry

“…This suggests that IB4 would not be a useful marker for a large population of non-CGRP containing colorectal afferents. Furthermore, in anterograde tracing studies, IB4-binding was not detectable in extrinsic axons innervating the guinea pig colon 15 .…”

“…Anterograde tracing of peripheral axons to the guinea pig rectum and colon showed that close to half of the filled axons in the myenteric plexus lacked any of the commonly used markers for sympathetic, parasympathetic or extrinsic sensory axons (ie: tyrosine hydroxylase, vesicular acetylcholine transporter, vasoactive intestinal polypeptide, nitric oxide synthase, somatostatin, vesicular glutamate transporters 1 and 2 or CGRP) 14,15 . Since spinal afferents constitute about one quarter of all extrinsic neurons projecting to the distal bowel of the guinea pig 16 , it is likely that spinal afferents that lack CGRP may contribute to this pool of "unlabelled" extrinsic axons.…”

“…In the guinea pig, anterograde tracing of lumbar colonic and rectal nerves has been used to characterise autonomic and sensory neurons to the distal colon and rectum 14,15 . Surprisingly, in both distal colon and rectum, a substantial proportion of extrinsic axons lacked any of the common markers (calcitonin gene-related peptide, vesicular acetylcholine transporter, tyrosine hydroxylase, vasoactive intestinal polypeptide, nitric oxide synthase, somatostatin, and vesicular glutamate transporters 1 and 2) that have previously been used to define autonomic and extrinsic sensory neurons 14,15 .…”

“…Surprisingly, in both distal colon and rectum, a substantial proportion of extrinsic axons lacked any of the common markers (calcitonin gene-related peptide, vesicular acetylcholine transporter, tyrosine hydroxylase, vasoactive intestinal polypeptide, nitric oxide synthase, somatostatin, and vesicular glutamate transporters 1 and 2) that have previously been used to define autonomic and extrinsic sensory neurons 14,15 . Retrograde tracing from the distal colon and rectum was used to analyse sympathetic and parasympathetic efferent pathways and the presence of key markers (tyrosine hydroxylase, nitric oxide synthase and choline acetyltransferase) in their nerve cell bodies 16 .…”

Alterations in the distal colon innervation in Winnie mouse model of spontaneous chronic colitis

“…Numbers of animals are shown in parentheses. *P<0.05, **P<0.01 2008;Chen et al 2015) as well as cell bodies of intrinsic noradrenergic and dopaminergic neurons…”