Caudal Mesenteric Ganglion Research Articles

The Influence of an Adrenergic Antagonist Guanethidine on the Distribution Pattern and Chemical Coding of Caudal Mesenteric Ganglion Perikarya and Their Axons Supplying the Porcine Bladder.

This study was aimed at disclosing the influence of intravesically instilled guanethidine (GUA) on the distribution, relative frequency and chemical coding of both the urinary bladder intramural sympathetic nerve fibers and their parent cell bodies in the caudal mesenteric ganglion (CaMG) in juvenile female pigs. GUA instillation led to a profound decrease in the number of perivascular nerve terminals. Furthermore, the chemical profile of the perivascular innervation within the treated bladder also distinctly changed, as most of axons became somatostatin-immunoreactive (SOM-IR), while in the control animals they were found to be neuropeptide Y (NPY)-positive. Intravesical treatment with GUA led not only to a significant decrease in the number of bladder-projecting tyrosine hydroxylase (TH) CaMG somata (94.3 ± 1.8% vs. 73.3 ± 1.4%; control vs. GUA-treated pigs), but simultaneously resulted in the rearrangement of their co-transmitters repertoire, causing a distinct decrease in the number of TH+/NPY+ (89.6 ± 0.7% vs. 27.8 ± 0.9%) cell bodies and an increase in the number of SOM-(3.6 ± 0.4% vs. 68.7 ± 1.9%), calbindin-(CB; 2.06 ± 0.2% vs. 9.1 ± 1.2%) or galanin-containing (GAL; 1.6 ± 0.3% vs. 28.2 ± 1.3%) somata. The present study provides evidence that GUA significantly modifies the sympathetic innervation of the porcine urinary bladder wall, and thus may be considered a potential tool for studying the plasticity of this subdivision of the bladder innervation.

Characterizing the autonomic neural connections between the abdominal aortic and superior hypogastric plexuses: A multimodal neuroanatomical study.

The aortic plexus serves as the primary gateway for sympathetic fibers innervating the pelvic viscera. Damage to this plexus and/or its associated branches can lead to an assortment of neurogenic complications such as bladder dysregulation or retrograde ejaculation. The neuroanatomy of this autonomic plexus has only recently been clarified in humans; as such, the precise function of its constituent fibers is still not clear. Further study into the functional neuroanatomy of the aortic plexus could help refine nerve-sparing surgical procedures that risk debilitating neurogenic complications, while also advancing understanding of peripheral sympathetic circuitry. To this end, the current study employed an in vivo electrostimulation paradigm in a porcine model, in combination with lipophilic neuronal tracing experiments in fixed, post-mortem human tissues, to further characterize the functional neuroanatomy of the aortic plexus. Electrostimulation results demonstrated that caudal lumbar splanchnic nerves provide primary control over the porcine bladder neck in comparison to other constituent fibers within the aortic plexus. Ex vivo human data revealed that the prehypogastric ganglion contains a significant number of neurons projecting to the superior hypogastric plexus, and that these neurons are arranged in a topographic manner within the ganglion. Altogether, these findings suggest that a pivotal sympathetic pathway mediating bladder neck contraction courses through the caudal lumbar splanchnic nerves, prehypogastric and inferior mesenteric ganglia and superior hypogastric plexus.

Endometritis Changes the Neurochemical Characteristics of the Caudal Mesenteric Ganglion Neurons Supplying the Gilt Uterus.

Simple SummaryUterine inflammation is a very frequent pathology in domestic animals leading to disturbances in reproductive processes and causing significant economic losses. The uterus possesses nerves from either the autonomic or sensory part of the peripheral nervous system. Most of the uterus-projecting neurons are localized in the caudal mesenteric ganglion. These neurons synthesize and release numerous biologically active substances in the uterus, which regulate uterine functions. The effect of inflammation on uterine innervation is poorly recognized. This study showed that Escherichia coli-induced uterine inflammation in pig led to a reduction in the total population of uterine neurons in the caudal mesenteric ganglion, and in the populations of these cells in the dorsal and central areas of this ganglion. In the caudal mesenteric ganglion of gilts after intrauterine bacterial injection, the population of uterine neurons presenting positive staining for dopamine-β-hydroxylase (an enzyme participating in noradrenaline synthesis) and negative staining for galanin, as well as the population of uterine neurons presenting negative staining for dopamine-β-hydroxylase but positive staining for neuropeptide Y, were decreased. In these gilts, there were increased numbers of uterine neurons which, besides dopamine-β-hydroxylase, also expressed neuropeptide Y, galanin and vasoactive intestinal peptide. The above changes suggest that inflammation of the gilt uterus may affect the function(s) of this organ by its action on the neurons of the caudal mesenteric ganglion.This study analyzed the influence of uterine inflammation on the neurochemical characteristics of the gilt caudal mesenteric ganglion (CaMG) uterus-supplying neurons. The horns of uteri were injected with retrograde tracer Fast Blue on day 17 of the first studied estrous cycle. Twenty-eight days later (the expected day 3 of the third studied estrous cycle), either saline or Escherichia coli suspension were administered into each uterine horn. Only the laparotomy was done in the control gilts. After 8 days, the CaMGs and uteri were harvested. The infected gilts presented a severe acute endometritis. In the CaMGs, the populations of uterine perikarya possessing dopamine-β-hydroxylase (DβH) and/or neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL) and vasoactive intestinal polypeptide (VIP) were analyzed using the double immunofluorescence method. In the CaMG, bacterial injection decreased the total number of the perikarya (Fast Blue-positive), the small and large perikarya populations in the dorsal and central regions, and the small and large perikarya populations coded DβH+/GAL- and DβH-/NPY+. After bacterial treatment, there was an increase in the numbers of small and large perikarya coded DβH+/NPY+, small perikarya coded DβH+/GAL+ and DβH+/SOM- and large perikarya coded DβH+/VIP+. To summarize, uterine inflammation influences the neurochemical characteristics of the CaMG uterus-supplying neurons, which may be important for pathologically changed organ functions.

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

The present study was designed to (1) ascertain the distribution and immunohistochemical characteristics of sympathetic preganglionic neurons supplying the caudal mesenteric ganglion (CaMG) and (2) verify the existence of viscerofugal projections from the urinary bladder trigone intramural ganglia (UBT-IG) to the CaMG in female pigs (n=6). Combined retrograde tracing and immunofluorescence methods were used. Injections of the neuronal tracer Fast Blue (FB) into the right CaMG revealed no retrogradely labelled (FB-positive; FB+ ) nerve cells in the intramural ganglia; however, many FB+ neurons were found in the spinal cord sympathetic nuclei. Double-labelling immunohistochemistry revealed that nearly all (99.4±0.6%) retrogradely labelled neurons were cholinergic (choline acetyltransferase-positive; ChAT+ ) in nature. Many FB+ /ChAT+ perikarya stained positive for vesicular acetylcholine transporter (63.11±5.34%), neuronal nitric oxide synthase (53.48±9.62%) or cocaine- and amphetamine-regulated transcript peptide (41.13±4.77%). A small number of the retrogradely labelled cells revealed immunoreactivity for calcitonin gene-related peptide (7.60±1.34%) or pituitary adenylate cyclase-activating polypeptide (4.57±1.43%). The present study provides the first detailed information on the arrangement and chemical features of preganglionic neurons projecting to the porcine CaMG and, importantly, strong evidence suggesting the absence of viscerofugal projections from the UBT-IG.

Distribution and immunohistochemical properties of autonomic neurons supplying the ovine hip joint capsule

Combined retrograde tracing and double labelling immunohistochemistry were applied to study the distribution and chemical coding of autonomic neurons projecting to the ovine hip joint capsule. As revealed by retrograde tracing, fast blue-positive autonomic neurons supplying the lateral side of the hip joint capsule and the medial side of the hip joint capsule were located within the lumbar and sacral of the ipsilateral sympathetic chain ganglia and within the caudal mesenteric ganglion. Immunohistochemistry revealed that nearly all (sympathetic chain ganglia: 96% and caudal mesenteric ganglion: 98.8%) the neurons were adrenergic in nature (positive for dopamine β-hydroxylase). Many retrogradely labelled neurons also displayed immunoreactivity to neuropeptide Y (approximately 34% of fast blue-positive neurons within caudal mesenteric ganglion and sympathetic chain ganglia). Populations of Met-Enk<sup>+</sup> (20%) and Leu-Enk<sup>+</sup> (6%) neurons were present only in the sympathetic chain ganglia while within caudal mesenteric ganglion no enkephalinergic-labelled neurons were noted. Only a small population (2.2%) of hip joint capsule-projecting neurons were Gal-IR and they were observed only within the caudal mesenteric ganglion. No cholinergic neurons involved in the innervation of the hip joint capsule were found. However, fast blue-positive nerve cell bodies were surrounded by numerous cholinergic nerve fibres often forming basket-like formations. Single Gal<sup>+</sup> nerve fibres were found in the intraganglionic connective tissue. Substance P-positive or calcitonin gene-related peptide-positive intraganglionic nerve terminals were very numerous and formed “baskets” surrounding fast blue-positive perikarya within sympathetic chain ganglias and caudal mesenteric ganglion.

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

Many studies examining the innervation of genitourinary structures focus on either afferent or efferent inputs, or on only one structure of the system. We aimed to clarify innervation of the bladder, external urethral sphincter (EUS) and clitoris. Retrograde dyes were injected into each end organ in female dogs. Spinal cord, mid-bladder, and spinal, caudal mesenteric, sympathetic trunk and pelvic plexus ganglia were examined for retrograde dye-labeled neurons. Neurons retrogradely labeled from the bladder were found primarily in L7-S2 spinal ganglia, spinal cord lateral zona intermedia at S1-S3 levels, caudal mesenteric ganglia, T11-L2 and L6-S2 sympathetic trunk ganglia, and pelvic plexus ganglia. The mid-bladder wall contained many intramural ganglia neurons labeled anterogradely from the pelvic nerve, and intramural ganglia retrogradely labeled from dye labeling sites surrounding ureteral orifices. Neurons retrogradely labeled from the clitoris were found only in L7 and S1 spinal ganglia, L7-S3 spinal cord lateral zona intermedia, and S1 sympathetic trunk ganglia, and caudal mesenteric ganglia. Neurons retrogradely labeled from the EUS were found in primarily at S1 and S2 spinal ganglia, spinal cord lamina IX at S1-S3, caudal mesenteric ganglia, and S1-S2 sympathetic trunk ganglia. Thus, direct inputs from the spinal cord to each end organ were identified, as well as multisynaptic circuits involving several ganglia, including intramural ganglia in the bladder wall. Knowledge of this complex circuitry of afferent and efferent inputs to genitourinary structures is necessary to understand and treat genitourinary dysfunction. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc.

Striated Perineal Muscles: Location of Somatic and Autonomic Neurons Projecting to the Male Pig Ischiocavernous Muscle. Neurochemical Features of the Sympathetic Subset.

The location, number and size of the central and peripheral neurons innervating the ischiocavernous muscle (ICM) were studied in male pigs by means of Fast Blue (FB) retrograde neuronal tracing. Moreover the immunohistochemical properties of the sympathetic ganglia were investigated combining the double immunolabeling method. After injection of FB into the left ICM, a mean number of 245.3 ± 134.9 labeled neurons were found in the ipsilateral ventral horn of the S1-S3 segments of the spinal cord (SC), 129.7 ± 45.5 in the L6-S3 ipsilateral and S2-S3 contralateral spinal ganglia (SGs), 2279.3 ± 622.1 in the ipsilateral L2-S2 and contralateral L5-S2 sympathetic trunk ganglia (STGs), 541.7 ± 158 in the bilateral caudal mesenteric ganglia (CMGs), and 78.3 ± 35.8 in the microganglia of the pelvic plexus (PGs). The mean area of the ICM projecting neurons was 1217 ± 69.7 μm2 in the SC, 2737.5 ± 176.5 μm2 in the SGs, 982.8 ± 36.8 μm2 in the STGs, 865.9 ± 39.14 μm2 in the CMGs and 426.2 ± 24.72 μm2 in the PGs. The FB positive neurons of autonomic ganglia contained Dopamine β hydroxylase, vesicular acetylcholine transporter, neuronal nitric oxyde sinthase, calcitonine gene related peptide, leu-enkephaline, neuropeptide Y, substance P, vasoactive intestinal polypeptide, and somatostatine often colocalized with tyrosine hydroxylase. The particular localization of the motor somatic nucleus, the abundant autonomic innervation and the qualitatively different content of ICM projecting sympathetic neurons suggest a complex regulation of this striated muscle involved in involuntary functions, such as the erection, ejaculation, micturition and defecation. Anat Rec, 301:837-848, 2018. © 2017 Wiley Periodicals, Inc.

Development of a Porcine Model to Study the Aortic Plexus and Innervation to the Internal Urethral Sphincter: Implications for Preventing Retrograde Ejaculation

INTRODUCTIONThe sympathetic nerves and ganglia overlying the abdominal aorta in humans are symmetrically organized into a bilateral network called the aortic plexus that must be spared during retroperitoneal surgery in order to maintain antegrade ejaculation. It is well established that complete resection of the aortic plexus causes retrograde ejaculation (RE) that results from de‐innervation of the internal urethral sphincter (IUS). At present, however, it remains uncertain which specific nerves of the aortic plexus control the IUS, and thus, which nerves are important for ejaculation.To ultimately determine which nerves are imperative to maintain ejaculation, the present study aimed to first establish the pig as a comparable model of the human aortic plexus in both structure and function. It was our working hypothesis that the pig exhibits comparable anatomy in terms of gross organization, number of infrarenal splanchnic nerves and constituent ganglia, and that stimulation of the left and right hypogastric nerves (homologous to the human superior hypogastric plexus) would evoke contraction of the IUS.METHODSThe porcine aortic plexus was examined in 18 boars by gross dissection followed by a histological examination to differentiate ganglia from nerve. Innervation of the IUS was examined using a lesion‐and‐test method, in which stimulation with a bipolar electrode was used to excite the hypogastric nerves distal to the caudal mesenteric ganglia before and after transection (n=5).RESULTSAs predicted, the anatomy of the porcine aortic plexus appeared comparable to humans, exhibiting two bilateral cords that were supplied by two or more infrarenal lumbar splanchnic nerves. Right and left caudal mesenteric and spermatic ganglia were invariably observed adjacent to their respective arteries, and given their topography within the plexus, they appear homologous to the prehypogastric, inferior mesenteric and spermatic ganglia in humans, respectively. At the junction of the upper infrarenal lumbar splanchnic nerves, two additional ganglia were observed within the cords of the porcine aortic plexus (prevalenceright = 4/8; prevalenceleft = 3/8); these structures have not been reported in humans. Electrostimulation of each hypogastric nerve evoked bladder neck contraction (ΔPright = 6.2 ± 2.2 mmHg, ΔPleft = 4.5 ± 2.2 mmHg), which was abolished following transection.CONCLUSIONSCollectively, our results confirm that the pig represents an effective preclinical model for studying not only the structure and normal function of the aortic plexus, but also the implications of unintended surgical trauma on the delicate nerves controlling ejaculation.Support or Funding InformationThis work is supported by CIHR

The Influence of Tetrodotoxin (TTX) on the Distribution and Chemical Coding of Caudal Mesenteric Ganglion (CaMG) Neurons Supplying the Porcine Urinary Bladder

The treatment of micturition disorders creates a serious problem for urologists. Recently, new therapeutic agents, such as neurotoxins, are being considered for the therapy of urological patients. The present study investigated the chemical coding of caudal mesenteric ganglion (CaMG) neurons supplying the porcine urinary bladder after intravesical instillation of tetrodotoxin (TTX). The CaMG neurons were visualized with retrograde tracer Fast blue (FB) and their chemical profile was disclosed with double-labeling immunohistochemistry using antibodies against tyrosine hydroxylase (TH), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), calbindin (CB), galanin (GAL) and neuronal nitric oxide synthase (nNOS). It was found that in both the control (n = 6) and TTX-treated pigs (n = 6), the vast majority (92.6% ± 3.4% and 88.8% ± 2%, respectively) of FB-positive (FB+) nerve cells were TH+. TTX instillation caused a decrease in the number of FB+/TH+ neurons immunopositive to NPY (88.9% ± 5.3% in the control animals vs. 10.6% ± 5.3% in TTX-treated pigs) or VIP (1.7% ± 0.6% vs. 0%), and an increase in the number of FB+/TH+ neurons immunoreactive to SOM (8.8% ± 1.6% vs. 39% ± 12.8%), CB (1.8% ± 0.7% vs. 12.6% ± 2.7%), GAL (1.7% ± 0.8% vs. 10.9% ± 2.6%) or nNOS (0% vs. 1.1% ± 0.3%). The present study is the first to suggest that TTX modifies the chemical coding of CaMG neurons supplying the porcine urinary bladder.

AB311. SPR-38 Clarification of the innervation of genitourinary structures: a neuronal tracing study in female mongrel hound dogs

ObjectiveMany studies focus on either afferent or efferent inputs (but not both), or on one structure of the genitourinary system. Only a few recent studies include information on inputs from sympathetic chain ganglia (SCG), and even fewer have examined the possibility of direct motor (autonomic or somatic) inputs from spinal cord ventral horns to genitourinary end organs. We sought to clarify origins of afferent and efferent information conveyed between the spinal cord, peripheral nervous system ganglia and genitourinary structures using retrograde and anterograde dye tracing methods.MethodsRetrograde dyes were injected into the bladder wall, EUS and clitoris of 14 female mongrel dogs (fluorogold, true blue, or nuclear yellow). Dorsal root ganglia (DRG), SCG, caudal mesenteric ganglion (CMG), pelvic plexus ganglia and spinal cord ventral horns were collected and examined for dye-labeled neuronal cell bodies. Detrusor muscle intramural ganglia were examined by injecting an anterograde dye (DiI) into the pelvic nerve’s anterior vesicle branch.ResultsRetrograde labeled cells were observed in several DRG, representative of afferent input from the bladder, EUS and clitoris. Anterograde labeling revealed a number of intramural ganglia in the bladder wall after distal pelvic nerve labeling. Sympathetic efferents included: (I) labeled cells in the CMG primarily from the bladder, yet small numbers from the EUS and clitoris; (II) labeled cells in SCG primarily from the bladder (widespread) and more localized input from EUS and clitoris; and (III) labeled cells in the intermediolateral cell column of thoracolumbar cord segments directly to the bladder and clitoris, a locale typically considered as sympathetic. Parasympathetic efferents included: (I) labeled neurons in pelvic plexus ganglia in bladder mesenteries; and (II) cells in lamina VII of sacral cord segments directly to the bladder and clitoris, a locale typically considered as sympathetic. Lastly, somatic (skeletal muscle) efferents to the EUS were evident as retrogradely labeled cells in sacral lamina IX cells.ConclusionsAfferent and efferent inputs to genitourinary structures are complex, yet a clear knowledge is needed to understand dysfunction after spinal cord injury and mechanisms underlying chronic pain syndromes in this region.Funding Source(s)NIH-NINDS NS070267

Immunohistochemical Properties of the Peripheral Neurons Projecting to the Pig Bulbospongiosus Muscle.

Retrograde neuronal tracing and single labelling immunofluorescence methods were used to define the neurochemical content of the peripheral autonomic and sensitive neurons projecting to the male pig striated bulbospongiosus muscle (BSM). The retrograde fluorescent neuronal tracer Fast Blue (FB) was injected into the left bulbospongiosus muscle of four intact impuberal pigs. After a 10-day survival time, the ipsilateral sacral sympathetic trunk ganglia (STGs), the caudal mesenteric ganglion (CMG), and the sacral spinal ganglia (SGs) were collected from each animal. In FB+ neurons of these ganglia, the presence of cathecolamine- (tyrosine hydroxylase-TH), acetylcholine- (vesicular acetylcholine transporter-VChAT), or nitric oxide-synthesizing (neuronal Nitric Oxide Synthase-nNOS) enzymes and of some biologically active peptides (calcitonine gene-related peptide-CGRP, Leu-Enkephaline-LENK, Neuropeptide Y-NPY, Substance P-SP and Vasoactive Intestinal Peptide-VIP) were studied. The ipsilateral STGs FB+ neurons showed immunoreactivity principally for TH and NPY and in decreasing order for VIP, VChAT, SP, CGRP, nNOS, and LENK. The left CMG FB+ neurons were immunoreactive to TH and NPY, and in smaller proportions for VIP, LENK, VChAT, CGRP, nNOS, and SP. The ipsilateral SGs FB+ neurons resulted immunoractive for CGRP, LENK, NPY, nNOS, SP, and VChAT. The heterogeneous neurochemical content of the peripheral neurons projecting to the pig BSM allows us to hypothesize the involvement of autonomic ganglia in the activity of both blood vessels and striated fibers of the muscle and the involvement of sensory ganglia in the afferent transmission from the muscle to spinal cord and in antidromic mechanisms that causes the relaxation of the BSM blood vessels. Anat Rec, 299:1192-1202, 2016. © 2016 Wiley Periodicals, Inc.

Caudal mesenteric ganglion in the sheep - macroanatomical and immunohistochemical study.

The caudal mesenteric ganglion (CaMG) is a prevetrebral ganglion which provides innervation to a number of organs in the abdominal and pelvic cavity. The morphology of CaMG and the chemical coding of neurones in this ganglion have been described in humans and many animal species, but data on this topic in the sheep are entirely lacking. This prompted us to undertake a study to determine the localization and morphology of sheep CaMG as well as immunohistochemical properties of its neurons. The study was carried out on 8 adult sheep, weighing from 40 to 60 kg each. The sheep were deeply anaesthetised and transcardially perfused with 4% paraformaldehyde. CaMG-s were exposed and their location was determined. Macroanatomical observations have revealed that the ovine CaMG is located at the level of last two lumbar (L5 or L6) and the first sacral (S1) vertebrae. The ganglion represents an unpaired structure composed of several, sequentially arranged aggregates of neurons. Immunohistochemical investigations revealed that nearly all (99.5%) the neurons were DβH-IR and were richly supplied by VACHT-IR nerve terminals forming "basket-like" structures around the perikarya. VACHT-IR neurones were not determined. Many neurons (55%) contained immunoreactivity to NPY, some of them (10%) stained for Met-ENK and solitary nerve cells were GAL-positive. CGRP-IR nerve fibres were numerous and a large number of them simultaneously expressed immunoreactivity to SP. Single, weakly stained neurones were SP-IR and only very few nerve cells weakly stained for VIP.

Reduction of the Number of Neurones in the Caudal Mesenteric Ganglion Innervating the Ovary in Sexually Mature Gilts Following Testosterone Administration

The effect of testosterone on the morphological and chemical plasticity of the porcine caudal mesenteric ganglion (CaMG) ovary-projecting neurones was investigated. To identify the neurones on day 3 of the oestrous cycle, the ovaries of both the control and experimental gilts were injected with Fast Blue retrograde neuronal tracer. From next day until day 20 of the anticipated second studied cycle, experimental gilts were injected with testosterone, whereas control gilts received oil. Testosterone injections increased testosterone (by approximately 3.5-fold) and 17β-oestradiol (by approximately 1.6-fold) levels in the peripheral blood and decreased the following in the CaMG: the total number of Fast Blue-positive perikarya (including small ones); the population of small perikarya in the caudal, ventral and dorsal ganglional regions; the numbers of dopamine-β-hydroxylase (DβH) and/or neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL) small and large perikarya; the numbers of small perikarya containing DβH (but not NPY, SOM, GAL); and the density of DβH and/or NPY, SOM nerve fibres. A disappearance of small and large non-noradrenergic perikarya and an increase in the total number of androgen receptor-immunoreactive perikarya was noted. Our results suggest that elevated androgen levels occurring during pathological states may regulate ovary function(s) by affecting the CaMG gonad-supplying neurones.

Localization of peripheral autonomic neurons innervating the boar urinary bladder trigone and neurochemical features of the sympathetic component

The urinary bladder trigone (UBT) is a limited area through which the majority of vessels and nerve fibers penetrate into the urinary bladder and where nerve fibers and intramural neurons are more concentrated. We localized the extramural post-ganglionic autonomic neurons supplying the porcine UBT by means of retrograde tracing (Fast Blue, FB). Moreover, we investigated the phenotype of sympathetic trunk ganglia (STG) and caudal mesenteric ganglia (CMG) neurons positive to FB (FB+) by coupling retrograde tracing and double-labeling immunofluorescence methods. A mean number of 1845.1±259.3 FB+ neurons were localized bilaterally in the L1-S3 STG, which appeared as small pericarya (465.6±82.7 µm2) mainly localized along an edge of the ganglion. A large number (4287.5±1450.6) of small (476.1±103.9 µm2) FB+ neurons were localized mainly along a border of both CMG. The largest number (4793.3±1990.8) of FB+ neurons was observed in the pelvic plexus (PP), where labeled neurons were often clustered within different microganglia and had smaller soma cross-sectional area (374.9±85.4 µm2). STG and CMG FB+ neurons were immunoreactive (IR) for tyrosine hydroxylase (TH) (66±10.1% and 52.7±8.2%, respectively), dopamine beta-hydroxylase (DβH) (62±6.2% and 52±6.2%, respectively), neuropeptide Y (NPY) (59±8.2% and 65.8±7.3%, respectively), calcitonin-gene-related peptide (CGRP) (24.1±3.3% and 22.1±3.3%, respectively), substance P (SP) (21.6±2.4% and 37.7±7.5%, respectively), vasoactive intestinal polypeptide (VIP) (18.9±2.3% and 35.4±4.4%, respectively), neuronal nitric oxide synthase (nNOS) (15.3±2% and 32.9±7.7%, respectively), vesicular acetylcholine transporter (VAChT) (15±2% and 34.7±4.5%, respectively), leuenkephalin (LENK) (14.3±7.1% and 25.9±8.9%, respectively), and somatostatin (SOM) (12.4±3% and 31.8±7.3%, respectively). UBT-projecting neurons were also surrounded by VAChT-, CGRP-, LENK-, and nNOSIR fibers. The possible role of these neurons and fibers in the neural pathways of the UBT is discussed.

Morphology of sympathetic chain in Saguinus niger

Saguinus niger popularly known as Sauim, is a Brazilian North primate. Sympathetic chain investigation would support traumatic and/or cancer diagnosis which are little described in wild animals. The aim of this study was to describe the morphology and distribution of sympathetic chain in order to supply knowledge for neurocomparative research. Three female young animals that came death by natural causes were investigated. Animals were fixed in formaldehyde 10% and dissected along the sympathetic chain in neck, thorax and abdomen. Cranial cervical ganglion was located at the level of carotid bifurcation, related to carotid internal artery. In neck basis the vagosympathetic trunk divides into the sympathetic trunk and the parasympathetic vagal nerve. Sympathetic trunk ran in dorsal position and originated the stellate ganglia, formed by the fusion of caudal cervical and first thoracic ganglia. Vagal trunk laid ventrally to heart and formed the cardiac plexus. In abdomen, on the right side, were found the celiac ganglion and cranial mesenteric ganglion; in the left side these ganglia were fusioned into the celiac-mesenteric ganglion displaced closely to the celiac artery. In both sides, the caudal mesenteric ganglion was located near to the caudal mesenteric artery.

Sensory and Autonomic Neurons Project Both to the Smooth Retractor Penis and to the Striated Bulbospongiosus Muscles. Neurochemical Features of the Sympathetic Subset

Aim of the present study was to verify, by means of double retrograde neuronal tracers technique, the hypothesis that a subpopulation of sensory and autonomic neurons send collateral axons to both smooth and striated genital muscles. We also wanted to define the neurochemical content of the eventually retrogradelly double labeled (RDL) neurons in the sympathetic trunk ganglia (STG). We used six intact pigs and we injected the tracer Diamidino Yellow (DY) in the smooth left retractor penis muscle (RPM) and the tracer Fast Blue (FB) in the striated left bulbospongiosus muscle (BSM). Rare (2 ± 0.6) RDL neurons were found in the ipsilateral S2 spinal ganglion (SG), 220 ± 42 in the ipsilateral STGs, from L3 to S3, 19 ± 15 in the contralateral S1-S2 ones and 22 ± 5 in the bilateral caudal mesenteric ganglia (CMG). The RDL neurons of the STG were IR for TH (85 ± 13%), DβH (69 ± 17%), NPY (69 ± 23%), nNOS (60 ± 11%), LENK (54 ± 19%), VIP (53±26%), SOM (40 ± 8%), CGRP (34 ± 12%), SP (31 ± 16%), and VAChT (28 ± 3%). Our research highlights the presence of sensory and sympathetic neurons with qualitatively different neurochemical content sending axons both to the smooth RPM and to the striated BSM of the pig. These RDL neurons are likely to project to the smooth vasal musculature to create the ideal physiological conditions in which these muscles can optimize the erectile function.

Ultrastructure of Neurons in the Caudal Mesenteric Ganglion in Kittens during Early Postnatal Ontogeny

Electron microscopic studies were performed to study the development of the neural elements of the sympathetic caudal mesenteric ganglion (CMG) in cats from the moment birth to the end of the second month of life. Non-simultaneous maturation of neurons and their terminals was seen; along with completely developed neurons, gliocytes, and synapses, neonatal kittens had numerous immature forms of these structures. In animals aged 14 days, the proportion of immature cells decreased, though neuron destruction was more frequent at this age. The CMG of animals of all age groups contained mostly axodendritic synapses, along with fewer axosomatic synapses. CMG ultrastructure in kittens became comparable with that in adult animals at age 60 days.

Experimental Study on the Location of Neurons Associated with the First Sacral Sympathetic Trunk Ganglion of the Pig

The neurons associated with the left first sacral sympathetic trunk ganglion (STG S1), an autonomic ganglion particularly concerned in the innervation of the smooth and striated musculature associated with pelvic organs, were identified in the pig, using the non-trans-synaptic fluorescent retrograde neuronal tracer Fast Blue. The labelled neurons were located mostly ipsilaterally, in the intermediolateral nucleus of the spinal cord segments T10-L5, in the sympathetic trunk ganglia L3-Co1, in the caudal mesenteric ganglia, in the pelvic ganglia, and in the spinal ganglia T13-S4. Our results could indicate the existence of visceral neuronal circuits concerning the ganglia of the sympathetic trunk and the caudal mesenteric, pelvic and spinal ganglia with or without the intervention of the central nervous system, whose identification and preservation during surgical treatments could be helpful in reducing the risk of subsequent urinary and sexual disfunctions.

Long-term estradiol-17β administration reduces population of neurons in the sympathetic chain ganglia supplying the ovary in adult gilts

Elevated levels of endogenous estrogens occurring in the course of pathological states of ovaries (follicular cysts, tumors) as well as xenoestrogens may result in hyperestrogenism. In rat, a close relationship between estrogens and sympathetic and sensory neurons supplying the genito-urinary system was reported. Recently, we have shown that long-term estradiol-17β (E 2) administration affected morphological and immunochemical organization of the sympathetic ovarian neurons in the caudal mesenteric ganglion of adult gilts. In this study, the influence of E 2 overdose on the number and distribution of neurons in the sympathetic chain ganglia (SChG) projecting to the ovary of adult pigs was investigated. The numbers of ovarian dopamine-β-hydroxylase (DβH-), neuropeptide Y (NPY-), somatostatin (SOM-), galanin (GAL-) and estrogen receptors (ERs-) immunoreactive perikarya as well as the density of the intraganglionic nerve fibers containing DβH and/or NPY, SOM, GAL were also determined. On day 3 of the estrous cycle the ovaries of both the control and experimental gilts were injected with retrograde neuronal tracer Fast Blue, to identify the neurons innervating gonads. From day 4 of the estrous cycle to the expected day 20 of the second studied cycle, the experimental gilts were injected with E 2, while the control gilts were receiving oil. After the last E 2/oil injection, the SChG Th16–S2 were collected and processed for double-labeling immunofluorescence. Injections of E 2: (1) increased the E 2 level in the peripheral blood ~ 4–5 fold, (2) reduced the total number of Fast Blue-positive postganglionic neurons in the ganglia under investigation, (3) decreased the number of perikarya in the L2–L4 ganglia, (4) reduced the number of perikarya in the ventral, dorsal and central regions of the SChG, (5) decreased the numbers of DβH +/NPY + and DβH +/GAL + perikarya and the numbers of DβH + but NPY −, SOM − and GAL − perikarya in the SChG, (6) decreased the number of perikarya expressing ERs subtype α and β, and (7) decreased the total number of the intraganglionic nerve fibers containing DβH and/or NPY. These results show that long-term E 2 treatment of adult gilts down-regulates the population of both noradrenergic and ERs expressing the SChG ovary supplying neurons. Our findings suggest also that elevated E 2 levels that occur during pathological states may regulate gonadal function(s) by affecting ovary supplying neurons.

The influence of ileitis on the neurochemistry of the caudal mesenteric ganglion in the pig

Some literature data suggest that there is a regulatory neuronal circuit between the small and the large bowel. To verify this hypothesis the present study investigated: (i) the distribution, chemical coding and routing of caudal mesenteric ganglion (CaMG) neurons participating in an intestinointestinal reflex pathway involving ileal descending neurons and viscerofugal colonic neurons and (ii) possible changes in the neuroarchitecture of this pathway evoked by chemically induced ileitis in juvenile pigs (n=16). Combined retrograde tract tracing and transections of the intermesenteric or caudal colonic nerves were applied. In addition, double immunostainings was used to investigate the chemical coding of retrogradely labeled CaMG neurons and intraganglionic nerve terminals apposed to them, under normal and inflammatory conditions. The majority of the ileum-projecting neurons were found in the caudal part of CaMG. Disruption of particular nerve pathways resulted in diminished number of retrogradely labeled neurons, ipsilateral to the side of manipulation. In normal pigs, ileum-projecting CaMG neurons stained for tyrosine hydroxylase, dopamine-β-hydroxylase, neuropeptide Y (NPY), somatostatin and galanin (GAL). The number and chemical coding of the neurons in the inflamed animals were similar to those observed in the normal pigs. However, in the inflamed pigs, the number of NPY-, GAL- or substance P-positive nerve terminals supplying retrogradely labeled neurons was increased. The present results suggest that inflammatory processes of the porcine ileum are able to induce changes in the intraganglionic architecture of a sympathetic ganglion located at discrete distance from the affected bowel segment.