Innervation and Neuronal Control of the Mammalian Sinoatrial Node a Comprehensive Atlas.

[Figure: see text].

Neural interrelationships of autonomic ganglia from the pelvic region of male rats.

The aims of the present study were to describe, in male rats, the anatomical organization of the major and accessory pelvic ganglia (MPG, AG; respectively), the interrelationship of the pelvic plexus components, and the morphometry of the pelvic postganglionic neurons. Anatomical, histochemical and histological studies were performed in anesthetized adult Wistar male rats. We found that the pelvic plexus consists of intricate neural circuits composed of two MPG, and three pairs of AG (AGI, AGII, AGIII) anatomically interrelated through ipsilateral and contralateral commissural nerves. Around 30 nerves emerge from each MPG and 17 from AGI and AGII. The MPG efferent nerves spread out preganglionic information to several pelvic organs controlling urinary, bowel, reproductive and sexual functions, while AG innervation is more regional, and it is confined to reproductive organs located in the rostral region of the urogenital tract. Both MPG and AG contain nerve fascicles, blood vessels, small intensely fluorescent cells, satellite cells and oval neuronal somata with one to three nucleoli. The soma area of AG neurons is larger than those of MPG neurons (p < 0.005). The MPG contains about 75% of the total pelvic postganglionic neurons. Our findings corroborated previous reports about MPG inputs, and add new information regarding pelvic ganglia efferent branches, AG neurons (number and morphometry), and neural interrelationship between the pelvic plexus components. This information will be useful in designing future studies about the role of pelvic innervation in the physiology and pathophysiology of pelvic 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.

A novel approach to mapping the atrial ganglionated plexus network by generating a distribution probability atlas.

INTRODUCTION: The ganglionated plexuses (GPs) of the intrinsic cardiac autonomic system are implicated in arrhythmogenesis. GP localization by stimulation of the epicardial fat pads to produce atrioventricular dissociating (AVD) effects is well described. We determined the anatomical distribution of the left atrial GPs that influence atrioventricular (AV) dissociation. METHODS AND RESULTS: High frequency stimulation was delivered through a Smart-Touch catheter in the left atrium of patients undergoing atrial fibrillation (AF) ablation. Three dimensional locations of points tested throughout the entire chamber were recorded on the CARTO™ system. Impact on the AV conduction was categorized as ventricular asystole, bradycardia, or no effect. CARTO maps were exported, registered, and transformed onto a reference left atrial geometry using a custom software, enabling data from multiple patients to be overlaid. In 28 patients, 2108 locations were tested and 283 sites (13%) demonstrated (AVD-GP) effects. There were 10 AVD-GPs (interquartile range, 11.5) per patient. Eighty percent (226) produced asystole and 20% (57) showed bradycardia. The distribution of the two groups was very similar. Highest probability of AVD-GPs (>20%) was identified in: inferoseptal portion (41%) and right inferior pulmonary vein base (30%) of the posterior wall, right superior pulmonary vein antrum (31%). CONCLUSION: It is feasible to map the entire left atrium for AVD-GPs before AF ablation. Aggregated data from multiple patients, producing a distribution probability atlas of AVD-GPs, identified three regions with a higher likelihood for finding AVD-GPs and these matched the histological descriptions. This approach could be used to better characterize the autonomic network.

Quantitative morphometric analysis of the myenteric nervous plexus ganglion structures along the human digestive tract.

BACKGROUND/AIM: All the functions of the digestive system are controlled, guided and initiated by the autonomic nervous system. A special part of this system placed in the wall of the gastrointestinal tract is known as the enteric or metasympathetic nervous system. The aim of this study was to analyse myenteric nervous plexus in different parts of the digestive tract. METHODS: We examined the myenteric nervous plexus of the esophagus, stomach, duodenum, jejunum, ileum, transverse colon and rectum in tissue samples taken from 30 cadavers of persons aged 20-84 years. After standard histological processing sections were stained with hematoxylin-eosin, cresyl violet (CV) and AgNO3 method. Multipurpose test system M42 was used in morphometric analysis. The results were analyzed by t-test and analysis of variance. RESULTS: The number of neurons per cm² surface was the lowest in the esophagus (2.045 ± 310.30) and the largest in the duodenum (65,511 ± 5,639). The statistical processing showed significant differences (P < 0.001) in the number of neurons between the esophagus and all other parts of the digestive tract. The maximal value of the average surface of the myenteric nervous plexus neurons was observed in the esophagus (588.93 ± 30.45 µm²) and the lowest in the stomach (296.46 ± 22.53 µm²). CONCLUSION: There are differences in the number of ganglion cells among different parts of the human digestive tract. The differences range from a few to several tens of thousands of neuron/cm2. The myenteric nervous plexus of the esophagus was characterized by a significantly smaller number of neurons but their bodies and nuclei are significantly larger compared to other parts of the digestive tract.

The subdiaphragmatic part of the phrenic nerve - morphometry and connections to autonomic ganglia.

Few anatomical textbooks offer much information concerning the anatomy and distribution of the phrenic nerve inferior to the diaphragm. The aim of this study was to identify the subdiaphragmatic distribution of the phrenic nerve, the presence of phrenic ganglia, and possible connections to the celiac plexus. One hundred and thirty formalin-fixed adult cadavers were studied. The right phrenic nerve was found inferior to the diaphragm in 98% with 49.1% displaying a right phrenic ganglion. In 22.8% there was an additional smaller ganglion (right accessory phrenic ganglion). The remaining 50.9% had no grossly identifiable right phrenic ganglion. Most (65.5% of specimens) exhibited plexiform communications with the celiac ganglion, aorticorenal ganglion, and suprarenal gland. The left phrenic nerve inferior to the diaphragm was observed in 60% of specimens with 19% containing a left phrenic ganglion. No accessory left phrenic ganglia were observed. The left phrenic ganglion exhibited plexiform communications to several ganglia in 71.4% of specimens. Histologically, the right phrenic and left phrenic ganglia contained large soma concentrated in their peripheries. Both phrenic nerves and ganglia were closely related to the diaphragmatic crura. Surgically, sutures to approximate the crura for repair of hiatal hernias must be placed above the ganglia in order to avoid iatrogenic injuries to the autonomic supply to the diaphragm and abdomen. These findings could also provide a better understanding of the anatomy and distribution of the fibers of that autonomic supply.

The Sphenopalatine Ganglion: Anatomy, Pathophysiology, and Therapeutic Targeting in Headache.

The sphenopalatine ganglion (SPG) has attracted the interest of practitioners treating head and face pain for over a century because of its anatomical connections and role in the trigemino-autonomic reflex. In this review, we discuss the anatomy of the SPG, as well as what is known about its role in the pathophysiology of headache disorders, including cluster headache and migraine. We then address various therapies that target the SPG, including intranasal medication delivery, new SPG blocking catheter devices, neurostimulation, chemical neurolysis, and ablation procedures.

Morphological evidence of local reflex arc in the rat's tongue.

Lingual components of the autonomic nervous system are considered to be the most rostral portion of the enteric nervous system. Therefore our aim was to study the intrinsic nerve cell bodies and synapses using immunohisto-, immunocytochemical methods. Several small groups of ganglia with cell bodies immunoreactive (IR) for vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and substance P (SP) were observed just below the gustatory epithelium. A few somatostatin and galanin IR nerve cell bodies were also found. Many IR cell bodies were also demonstrated in the glands and next to blood vessels. Some of these cell bodies were multipolar and some of them were small neurons with an ovoid shape having only one process. Cell bodies positive for calcitonin gene-related peptide (CGRP) were detected neither in the superficial nor in the deep portion. Electronmicroscopical analysis demonstrated different IR nerve fibres having axo-somatic and axo-dendritic synapses with other immunonegative cells. In a few cases VIP IR nerve processes were found to synaptize with other VIP positive nerve cell bodies. These results support the existance of intralingual reflex in the tongue, where the ganglia might have an integrative role of the different neuropeptide containing nerve fibres.

The spermatic ganglion in humans: an anatomical update.

The male gonad receives nerve fibers from the autonomic ganglionic system. By the present study, we aimed to bring detailed evidences, topographic and structural, on the spermatic ganglia (SG) in humans, as suppliers of autonomic fibers for the testis. We performed retroperitoneal dissections in 25 formalin-fixed human male adult cadavers. Histology used the Hematoxylin-Eosin and we also used Bielschowsky silver stains. Immunohistochemistry used antibodies for tyrosine hydroxylase. In 20÷10 specimens, we identified left spermatic ganglia (LSG) at the aortic origin of the left testicular artery (LTA); in five specimens the LTA left the renal artery but LSG were juxtaposed on the aorta at about the level of origin of a normal LTA. In 15÷25 cadavers, there were right spermatic ganglia (RSG) related to the right testicular artery (RTA) that in 12 cadavers had a precaval disposition. A specimen with retrocaval RTA presented an inferior renal ganglion, supplying both the renal and the RTA. The SG presented renal, lumbar and intermesenteric roots. The inferior branch of the SG connected it to the inferior mesenteric plexus while its infero-lateral branch adjoined the testicular artery. Microscopy confirmed the SG as nervous ganglia and the respective neuronal populations were tyrosine hydroxylase positive, allowing us to consider these ganglia as sympathetic. We bring here the first-time evidence of the SG topography and cathecolaminergic nature in humans; this ganglion may influence the male gonad via the inferior mesenteric plexus and via the vascular path of the testicular artery.

Accessory lumbar splanchnic ganglia in humans: a case report.

The present study was designed and performed on 20 human adult cadavers at the level of the retroperitoneal space in order to provide evidence of the paravertebral and prevertebral sympathetic ganglia. Only one specimen, male, presented two ganglia on the left side located on the first lumbar splanchnic nerve, one proximal and the other distal. The macroscopically detected swellings were drawn and certified as autonomic ganglia after performing silver stains by the method of Bielschowsky (on blocks). No existing reference to date mentions such lumbar splanchnic ganglia, which could be the result of a fragmentation followed by displacement from the lumbar sympathetic trunk. Their demonstrated anatomical connections with the afferents of the spermatic ganglion and the intermesenteric plexus may indicate the involvement of these ganglia in vasomotor and gonadal functions.

Prenatal development of the human epicardiac Ganglia.

The aim of this study was to determine the developmental anatomy of intrinsic cardiac ganglia with respect to epicardiac ganglionated nerve plexus in the human fetuses at different gestation stages. Twenty fetal hearts were investigated applying a technique of histochemistry for acetylcholinesterase to visualize the epicardiac neural ganglionated plexus with its subsequent examinations on total (non-sectioned) hearts. Most epicardiac ganglia embodied multilayered neurons and were oval in shape, but some ganglia involved neurons lying in one layer or had the irregular appearance because of their extensions along inter-ganglionic nerves. The mean ganglion area of fetuses at gestation stages of 15-40 weeks was 0.03 +/- 0.008 mm(2). The largest epicardiac ganglia, reaching in area 0.4 mm(2), were concentrated on the dorsal surface of both atria. The particular fused or "dual" ganglia were identified at the gestation stages of 23-40 weeks, but they composed only 2.3 +/- 0.7% of all found epicardiac ganglia. A direct positive correlation was determined between the fetal age and the ganglion area (mm(2)) as well as between the fetal age and the number of inter-ganglionic nerves. The revealed appearance of epicardiac ganglia in the human fetuses at 15-40 weeks of gestation confirms their prenatal development and presumable intrinsic remodelling.

Anatomic study of human laryngeal ganglia: number and distribution.

We have studied 12 laryngeal nerves: six internal branches of the superior laryngeal nerve (ILN) and six recurrent laryngeal nerves (RLN) from three human adult larynges (two males and one female). After dissection of each individual laryngeal nerve using a surgical microscope, the nerves were preserved in 10% formalin, embedded in paraffin wax, serially sectioned transversely at a thickness of 10 microm and stained with hematoxylin and eosin. We found 2-4 ganglia associated with the ILN. At least two ganglia were always present (six out of six cases), the largest one being associated with the branch of the nerve innervating the vestibule and the smallest one associated with the branch innervating the aryepiglottic fold. Other ganglia were found associated with the branches for the glosso-epiglottic fold and vallecula (four out of six cases) and interarytenoid muscle (three out of six cases). The RLN showed from two to six ganglia, all of them located in its anterior terminal division. Two of the ganglia were located in the part of the nerve between the origin of the branches for the interarytenoid and lateral cricoarytenoid muscles (three out of six cases). The remaining ganglia were located close to or at the origin of the muscular branches innervating the intrinsic laryngeal muscles. The cytology of the ganglia reported suggests that they were all autonomic in nature, probably parasympathetic.

[Dissection of cavernous nerves in rat and model of neurological erectile dysfunction].

OBJECTIVES: To identify rat cavernous nerve and establish a rat model of erectile dysfunction caused by injury of cavernous nerve. METHODS: Ten rats were undergone dissections. 30 experimental rats were randomized into 2 groups, cavernous nerve were identified by electrical stimulation. One month after surgery, rat models were evaluated by electrical stimulation. RESULTS: The anatomic structure of cavernous nerve in rats are highly similar to human beings, the erection can be evoked by stimulating cavernous nerves, and after cavernous nerve injury it can not be evoked (P < 0.05). CONCLUSION: Because of the highly similarity of cavernous nerve between rats and human beings, so as the suitable price, rat should be used as the ideal ED experimental animal. The model of ED caused by cavernous nerve injury is reliable.

[Distribution of the epicardiac neural ganglia in human fetuses of different age]. / Epikardiniu nerviniu mazgu pasiskirstymas skirtingo amziaus zmogaus vaisiuje.

OBJECTIVE: The epicardiac neural ganglia of the adult human heart are distributed in the seven neural ganglionated subplexuses. The aim of the present investigation was to determine the distribution of the epicardiac ganglia in human fetuses of different age, because intrinsic cardiac nervous system of the human fetus has not been enough investigated so far. MATERIAL AND METHODS: In the present study seventeen human fetus hearts were investigated, in which epicardiac neural ganglionated plexus was visualized by histochemical method for acetylcholinesterase. RESULTS: Analysis of the total hearts preparations showed that: (1) the epicardiac neural ganglionated plexus of the fetus at fifteen weeks of gestation has already differentiated into seven ganglionated subplexuses, structure of which is typical for the adult human heart; (2) the epicardiac plexus of fetuses at 15-40 weeks of gestation contains on average 865+/-40 epicardiac ganglia, that may widely range in number from 644 to 1193; (3) the largest number of the neural ganglia is concentrated on the posterior surface of both atria, where up to 76% of all ganglia maybe located; (4) the difference between the number of epicardiac ganglia in the human fetuses at the early (15-25 weeks) and late (26-40 weeks) stages of fetogenesis is not statistically significant (p>0.05). In conclusion, both the distribution and the number of the epicardiac ganglia of fetuses ranging from 15 to 40 weeks of gestation are not age-dependent but varied substantially from heart to heart.

Comparative anatomical study of the autonomic cardiac nervous system in macaque monkeys.

The main aim of this study was to clarify the general morphology of the autonomic cardiac nervous system in macaque monkeys. A submacroscopic comparative anatomical study of the autonomic cardiac nervous system was performed by examining 22 sides of 11 bodies of four species of macaque monkeys, including some previously unreported species (pig-tailed and stump-tailed monkeys), under a surgical stereomicroscope. The following results were obtained. 1) The basic arrangement of the autonomic cardiac nervous system is constant in all examined macaques. 2) A superior cardiac nerve originating from the superior cervical ganglion was not observed, whereas the thoracic cardiac nerve originating from the sympathetic trunk/ganglia under the cervicothoracic ganglion was rarely observed in all the examined macaques. 3) The main cardiac nerve is the middle cardiac nerve originating from the middle cervical ganglion, similar to the situation in humans. 4) Although the superior, inferior, and thoracic cardiac branches of the vagus nerve were consistently observed, the left thoracic cardiac branch is rarely absent because of its lower origin to the heart. 5) The cranial autonomic nerves tend to distribute into the heart medially (arterial porta), and the caudal autonomic nerves tend to distribute into the heart laterally (venous porta). To comprehend the comparative morphological and evolutionary changes more completely, these results were compared with our previous studies and some references. Consequently, differences in the sympathetic cardiac nerves of macaques and humans are recognized, in spite of the similar morphologies of the vagal cardiac branches. These differences include the composition of the cervicothoracic ganglion, the lower positions of the middle cervical and cervicothoracic ganglia, and the narrow range for the origin of the cardiac nerves in macaques compared to that in humans.

[Abdominal aortal plexus in fur animals (order Carnivora)]. / Morfologicheskie osobennosti briyshnogo aortal'nogo spleteniia u pushnykh zverei otriada khishchnykh.

Abdominal aortal plexus was studied in foxes, polar foxes, sables and minks using macro-microscopic method of V.P. Vorobjov. Nerve ganglia of the abdominal aortal plexus in all examined fur animals are located at the roots of the largest arterial vessels originating from abdominal aorta and they are represented by paired abdominal, unpaired cranial mesenterial (excluding minks), inconstant visceral and aorto-renal, plural intermesenterial, single or plural caudal mesenterial nerve ganglia.

Localization of neurons projecting into the extrinsic penile smooth musculature of the pig: an experimental study on the retractor penis muscle.

The aim of this study was to locate in male pigs the sensory and autonomic ganglia innervating the retractor penis muscle (RPM), which was taken as an experimental model of the genital smooth musculature. The retrograde neuronal tracers horseradish peroxidase (HRP), Fast Blue (FB), and diamidino yellow (DY) were injected into the bulbopenile portion of the left RPM. The tracers highlighted a different affinity for the neuronal structures, although labelled cells supplying the RPM were generally found in bilateral dorsal root ganglia (DRGs, S1-S3), in bilateral paravertebral ganglia (PaGs, L2-S3), and in the left and right caudal mesenteric ganglia (CMGs). The mean number of labelled FB cells was 795 (range, 645-952) in DRGs, 16046.25 (range, 10226-18742) in PaGs, and 635.25 (range, 333-786) in CMGs. The mean diameter of pseudounipolar DRG cells was 60-75 microm, while the multipolar neurons of PaGs and CMGs had dimensions varying between 20-50 microm and 20-30 microm, respectively.

Extrinsic cardiac nerve segments in the domestic dog (Canis familiaris- Linnaeus, 1758). Comparative study in young and adult dogs.

In this paper, important connections between the two main contingents of the autonomic nervous system, intrinsic and extrinsic visceral plexus were analysed. Concerning heart innervation, the territories of extrinsic innervation are very important in the treatment of congenital or acquired cardiopathy, thoracic neoplasia and aortic arch persistence, among others. This research compared young and adult extrinsic cardiac innervation and described the surgical anatomic nerve segments. Animals were perfused with a 10% formaldehyde solution in PBS (0.1 m) (pH 7.4) and submitted to macro- and meso-scopic dissection immersed in 60% acetic acid alcoholic solution and 20% hydrogen peroxide aqueous solution. The nerve segments were assigned as: right vagus nerve segment, left vagus nerve segment, right middle cervical ganglion segment, left middle cervical ganglion segment, right caudal laryngeal nerve segment, left caudal laryngeal nerve segment, right phrenic nerve segment and left phrenic nerve segment.