Immunohistochemical characteristics and distribution of neurons in the intramural ganglia supplying the urinary bladder in the male pig

Abstract

This study investigated the distribution and chemical coding of neurons in intramural ganglia of the urinary bladder trigone (UBT-IG) and cervix (UBC-IG) in the male pig using combined retrograde tracing and double-labelling immunohistochemistry. Additionally, immunoblotting was used to confirm the presence of marker enzymes for main populations of autonomic neurons. Retrograde fluorescent tracer Fast Blue (FB) was injected into the wall of both the left and right side of the bladder trigone, cervix and apex during laparotomy performed under thiopental anaesthesia. Twelve μm-thick cryostat sections were processed for double-labelling immunofluorescence with antibodies against tyrosine hydroxylase (TH), dopamine β-hydroxylase (DBH), neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL), vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), calcitonin gene-related peptide (CGRP), substance P (SP) and vesicular acetylcholine transporter (VAChT). UBT-IG and UBC-IG neurons in both parts of the organ formed characteristic clusters (from few to tens of neuronal cells) found under visceral peritoneum or in the outer muscular layer. Immunohistochemistry revealed several subpopulations in UBT-IG and UBC-IG neurons, namely noradrenergic (ca. 76% and 76%), cholinergic (ca. 22% and 20%), non-adrenergic/non-cholinergic nerve cells (ca. 1.5% and 3.8%), NPY-(ca. 66% and 58%), SOM-(ca. 39% and 39 %), VIP-(ca. 5% and 0%) and NOS-immunoreactive (IR) (ca. 1.5% and 3.8%), respectively. Immunoblotting using antibodies to TH and VAChT showed the presence of studied proteins as revealed by the presence of protein bands of the correct molecular weight. This study has revealed a relatively large population of differently coded UBT-and UBC-IG neurons, which constitute an important element of the complex neuroendocrine system involved in the regulation of the male urogenital organs function.

Clarification of the Innervation of the Bladder, External Urethral Sphincter and Clitoris: A Neuronal Tracing Study in Female Mongrel Hound Dogs

“…Intramural ganglion neurons are post‐ganglionic neurons located in the bladder wall between detrusor smooth muscle bundles (Pidsudko, ; Barbe and Ruggieri, ), and are therefore distinct from pelvic plexus ganglionic neurons located in mesenteries external to the bladder. Although often left out of schematics of bladder innervation, it has long been known that intramural ganglion neurons are present in the bladder wall of most mammalian species (Kuntz and Moseley, ).…”

A study on preganglionic connections and possible viscerofugal projections from urinary bladder intramural ganglia to the caudal mesenteric ganglion in the pig

“…One of the sources of autonomic innervation of this organ are ganglia distributed in its wall (Gabella, ; Dixon et al. ; Pidsudko, ). Intramural ganglia are associated with many visceral organs, but the most numerous are those of the gastrointestinal tract (Furness et al.…”

“…the collection and storage of urine and its periodic emptying, are regulated by complex neuronal pathways (de Groat, 2006). One of the sources of autonomic innervation of this organ are ganglia distributed in its wall (Gabella, 1990;Dixon et al 2000;Pidsudko, 2013). Intramural ganglia are associated with many visceral organs, but the most numerous are those of the gastrointestinal tract (Furness et al 2004).…”

“…), guinea pigs (Crowe et al. ; Gabella, ) and pigs (Pidsudko, , ). Despite this, no attempts have been made to investigate the existence of possible viscerofugal projections from these ganglia.…”

“…For instance, few or no nerve cells have been found in the urinary bladder wall of the rat (Uvelius & Gabella, 1995;Zvarova & Vizzard, 2005) or mouse (Grozdanovic et al 1992). However, UB-IG are very numerous in humans (Dixon et al , 2000Gilpin et al 1983), guinea pigs (Crowe et al 1986; Gabella, 1990) and pigs (Pidsudko, 2004(Pidsudko, , 2013. Despite this, no attempts have been made to investigate the existence of possible viscerofugal projections from these ganglia.…”