Morphology and immunohistochemical characteristics of the otic ganglion in the chinchilla (Chinchilla laniger Molina).

INTRODUCTION: The available literature provides relatively little information on the morphology of the autonomic head ganglia in rodents including their neurochemical codding. MATERIAL AND METHODS: Morphological investigations of the otic ganglion of the chinchilla were performed using the modified acetylcholinesterase method. The cellular structure was investigated with histological techniques and neurochemical properties were studied with the double-labelling immunofluorescence method. RESULTS: Macromorphological investigations allowed the otic ganglion to be identified as a compact, oval agglomeration of neurons and nerve fibers. Multidimensional cross-sections revealed densely arranged neuronal perikarya and two populations of nerve cells differing in size were distinguished. The large cells (40-50 µm) accounted for about 80% of the neurons in the cross-sections. Moreover, a small number of intraganglionic nerve fibers was observed. Immunohistochemical staining revealed that over 85% of the neuronal cell bodies in the otic ganglion contained immunoreactivity to VAChT or ChAT. VIP-immunoreactive perikarya comprised approximately 10% of the ganglionic cells. Double staining revealed the presence of VAChT+ and NOS+ neurons which amounted to about 45% of the nerve cells in the otic ganglion. NOS+ only perikarya comprised approx. 15% of all the neurons. Immunoreactivity to enkephalins, substance P, somatostatin, and galanin was expressed in single nerve cell bodies and nerve fibers except numerous substance P+ intraganglionic nerve fibers. Some of them were stained also for CGRP. Single neurons stained for tyroxine hydroxylase. CONCLUSIONS: Our results, compared with findings in other rodent species suggest the existence of interspecies differences in the morphology, cellular structure, and immunohistochemical properties of the head autonomic ganglia in mammals.

The right coronary artery in the heart of chinchilla (Chinchilla laniger Molina).

The pattern of normal coronary vascularization in a mammalian heart includes the presence of both right and left coronary arteries. According to the literature data, the presence of single major coronary arteries is mainly related to cardiac abnormalities. Previously it has been reported that the right coronary artery is absent in the coronary vascularization of the heart in the chinchilla. Our research was carried out on thirty chinchillas (Chinchilla laniger Molina). The coronary vessels were filled with colored latex to render them visible. The examinations were supplemented additionally with the use of microcomputed tomography with arterial contrast. Our study demonstrates its undoubtedly presence of the right coronary artery. In all subjects the right coronary artery was present, as was the left coronary artery. Two types of right coronary artery were found. Our results indicate that the normal pattern of coronary vascularization of heart in chinchilla includes both the right and left coronary arteries. An open question remains the presence of single coronary artery is a normal pattern of cardiac arterial vascularization in chinchilla.

Distribution and neurochemical characteristic of the cardiac nerve structures in the heart of chinchilla (Chinchilla laniger Molina).

INTRODUCTION: The heart innervation is made up of plexo-ganglionic formation containing sympathetic, parasympathetic, and sensory components. We examined the distribution and neurochemical coding of the ganglia and nerve fibers in the chinchilla's heart. MATERIAL AND METHODS: The heart sections of 10 male and 10 female adult chinchillas were processed in accordance with the thiocholine method for acetylcholine esterase (AChE), and the SPG method for detecting the presence of adrenergic fibers was applied. The routine technique of immunohistochemical (IHC) staining with primary antibodies directed against ChAT, VAChT, DbH, TH, CART, NPY, VIP, GAL and SOM was used. The secondary antibodies were conjugated with Alexa Fluor 488 and Alexa Fluor 555 fluorophores. RESULTS: The epicardium contained ganglia and nerve fibers, the myocardium had a few ganglion neurocytes and nerve fibers, and the endocardium contained only nerve fibers. In the epicardium, AChE-positive fibers were more prevalent than SPG-positive fibers. All the ganglion cells were immunopositive for ChAT and VAChT. Some cells also had a positive reaction to DbH and TH. Fibers containing cholinergic and adrenergic markers were numerous, while many of them were ChAT/DbH- and VAChT/TH-positive. CART/NPY and CART/VIP, as well as CART and GAL, were observed to be colocalized in ganglion neurocytes, as well as in individual cells. The nerve fibers were found to contain all the neurotransmitters we tested for, as well as the following co-occurrences: ChAT/DbH, VAChT/TH, CART/NPY, CART/VIP, CART/GAL, and CART/SOM. CONCLUSIONS: Our analysis of the neurochemical profile of the nerve structures in chinchilla's heart showed that, despite interspecies differences, the general pattern of the distribution of autonomic nervous system structures is similar to that of other mammals' species, including humans.

Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina).

INTRODUCTION: Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina) was examined in this study. The pancreas is both an exocrine and endocrine gland with autonomic and sensory innervation presented by the numerous nerve fibers and small agglomerations of nerve cells. MATERIAL AND METHODS: Investigations were performed on 16 adult chinchillas of both sexes. The material was collected immediately after death of the animals. Histochemical methods: AChE and SPG were used, in addition to routine technique of single and double immunohistochemical (IHC) staining using whole mount specimens and freezing sections with a thickness of 8 to 12 µm. In the immunofluorescence staining, primary antibodies directed against markers used to identify cholinergic - ChAT and VAChT, and adrenergic - DbH and TH neurons. Secondary antibodies were coupled to Alexa Fluor 488 and Alexa Fluor 555 fluorophores. RESULTS: Histochemical studies (AChE) revealed that chinchilla pancreatic cholinergic innervation consisted of ganglionic neurocytes and numerous nerve fibers. These structures are located in the parenchyma of the exocrine part of the organ in close proximity to blood vessels and are present within the walls of the pancreatic ducts and interstitial connective tissue. A delicate fiber network around the Langerhans islets was also observed. The most numerous cholinergic structures were found in the head and tail, and the least numbers were found in the body of the pancreas. The SPG method revealed that adrenergic fibers form a network in the adventitia of blood vessels, and individual fibers run throughout the pancreatic parenchyma. Moreover, adrenergic nerve fibers were observed around the ganglionic neurocytes. This innervation was similar in all parts of the investigated organ. IHC investigations allowed observations of both the cholinergic and adrenergic activities of autonomic nerve structures. Additionally, using ChAT/DbH double staining, colocalization of these substances was observed in the fibers of the pancreatic parenchyma that passed through the cholinergic ganglia. Colocalization of VAChT and TH was found in nerve fibers of the exocrine part, in the walls of blood vessels, and in individual nerve cells. Colocalization of ChAT/DbH and VAChT/TH was observed in the single nerve cells and in the small (2-3 cell) ganglia. ChAT- and DbH-immunopositive nerve fibers were found in the area of the islets of Langerhans. CONCLUSIONS: The results indicate a more intense cholinergic innervation of the chinchilla's pancreas, which is represented by both ganglia and nerve fibers, while adrenergic structures are mainly represented by fibers and only single neurocytes. This arrangement of the investigated structures in this species may imply a major role for hormonal control of exocrine secretion in rodents.

The Stapedial Artery in the Mongolian Gerbil (Meriones unguiculatus).

The persistent stapedial artery is a component of the main arterial roads of the head in some animal groups (Frackowiak: Roczn Akad Roln Poznan 336 (2003) 1-81). This type of vascularization occurs in the Mongolian gerbil, among others. The stapedial artery is common in a variety of forms in rodents. It has been described, for example, in Sciuridae, Muridae, Heteromyidae, Geomyidae, Splacidae, Cricetidae, Arvicolinae, and in genus Jaculus (Cox and Hautier: Evolution of the Rodents: Advances in phylogeny, Functional Morphology and Development, 2015). The aim of this study was the analysis of morphology, and of course, of the stapedial artery in this species. Investigations were performed on 10 animals of both sexes, weighing 50-60 g. After lethal anesthesia, the vascular system of every animal was filled with colored latex. After latex coagulation and decalcification of skull bones, fixed tissues were delicately prepared, and the head vascular system was exposed. The stapedial artery separates from the internal carotid artery, runs toward the auditory bulb and passes through the stapes. After the branching of the medial meningeal artery, the stapedial artery runs rostrally, forming its infraorbital branch. This branch, in the further course, gives the branch forming the short trunk of the ophthalmic artery, which supplies orbital structures (muscles, lacrimal gland, Harderian gland, and eyeball). The performed investigations revealed that the maintained infraorbital branch of the stapedial artery is the only source of arterial supply of the orbit in this species. Anat Rec, 301:1131-1137, 2018. © 2018 Wiley Periodicals, Inc.

Internal Ophthalmic Arteries Within the Brain-Base Arterial System in Guinea Pig.

In situ vascular specimens of the arterial circle were collected from 15 adult guinea pigs, both male and female. After specimen preparation, the vessels were filled with synthetic latex and subjected to analysis. Similar as in the case of other rodents, vertebral arteries were merged into basilar artery, further dividing into two short terminal branches. Distally, the terminal branches extend into caudal cerebral arteries. Rostral part of the arterial circle of brain is supplied with blood from maxillary arteries via external and internal ophthalmic arteries connected by a short anastomosis. This type of vascularity may probably be considered a functional analogy to the internal carotid arteries observed in other species. Rostral and caudal parts of the arterial circle of brain are connected by exceptionally long caudal communicating arteries. In author's opinion, the disputable contribution of internal carotid artery and the exceptional contribution of internal ophthalmic arteries in the cerebral blood supply in guinea pigs as compared to other rodents, warrants further research on the subject. Anat Rec, 301:887-891, 2018. © 2017 Wiley Periodicals, Inc.

Morphometry and Variability of the Brain Arterial Circle in Chinchilla (Chinchilla laniger, Molina).

Arterial circles of brains from 70 adult chinchillas were filled with synthetic latex. The arterial circle of the brain is formed as the result of vertebral arteries being merged into the basilar artery. Caudally, both vertebral arteries gave rise to the ventral spinal artery. The ventral spinal artery splits into tiny cerebellar vessels, the pontine and cochlear branches. Distally, the basilar artery ramified into two terminal branches that formed the arterial circle of brain, rostrally open in most cases (75%). The observed variability of the arterial circle of brain of chinchillas pertained to all elements of that circle. The greatest variability within the vessels of the circle of Willis in chinchillas was observed in 22 cases (31.4%) of internal ophthalmic arteries. In chinchillas, a trend toward slight variability within the arteries comprising the arterial circle of the brain was observed in 44 animals. This accounted for 62.8% of all cases. Only in three cases was the arterial circle of brain clearly symmetrical. At the same time, 23 animals (32.8%) revealed features of significant vascular variability within the brain base region. These consisted of disturbed geometry of the entire arterial circle, different levels of ramifications into individual arteries, as well as the number and diameter of arteries. No internal carotid arteries were observed in chinchillas apart from one atypical case in which the carotid artery extended unilaterally into the basilar artery. These investigations indicate on the significant variability of arterial circle in rodents. Anat Rec, 300:1472-1480, 2017. © 2017 Wiley Periodicals, Inc.

Morphology and Topography of the Celiac Plexus in Degu (Octodon Degus).

Here, we investigate the morphology and topography of the celiac plexus components in degu (Octodon degus). The study was performed using six adult individuals of both sexes. Macromorphological observations were performed using a derivative of the thiocholine method specially adapted for this study type (Gienc, 1977). The classical H&E technique was used for analysis of the cytoarchitectonic of the ganglion, and the AChE (Karnovsky and Roots, 1964) and SPG (De la Torre, 1980) techniques to observe cholinergic and adrenergic activity. The celiac plexus of degu is located on the ventral and lateral surface of the abdominal aorta, at the level where the celiac artery separates from the aorta. This structure consists of two large and two smaller aggregations of neurocytes connected with postganglionic fibers. Histochemical investigations have demonstrated the mainly cholinergic characteristic of the intraganglionic and postganglionic fibers of the celiac plexus, while the adrenergic fibers accompanied only the blood vessels and neurocytes revealed differentiation of adrenergic activity. Histological analysis revealed that neurocytes occupied about half of the cross-section area, with the nerve fibers, connective tissue, and blood vessels forming the remaining part. Ganglionic cells were oval, and usually contained a single nucleus, although two nuclei were sometimes observed.

Anatomical and histological data on the ciliary ganglion in the Egyptian spiny mouse (Acomys cahirinus Desmarest).

The morphology and topography of the ciliary ganglion in the Egyptian spiny mouse were studied with use of histochemical and histological techniques. The ciliary ganglion of the Egyptian spiny mouse consisted of between 3 and 4 agglomerations of nerve cells. The largest was situated at the point where the ventral branch of the oculomotor nerve divides into two branches. The next two smaller aggregations were located on the superior and lateral surfaces of the optic nerve where it crossed the oculomotor nerve. From the main agglomerations of neurocytes arose between 3 and 4 intensively stained postganglionic cholinergic fibres. These followed the optic nerve to the eyeball. On the cross-sections of these bundles small agglomerations of neurocytes were observed. These decreased in size to only 2 or 3 cells towards the sclera. The ganglionic neurocytes in the largest ganglion varied from 15 to 30 microm in diameter. They were distributed uniformly over the whole surface of the sections. All the ganglia had connective capsules.

A comparative study on the morphology and topography of the ciliary ganglion in midday gerbil (Meriones meridianus) and turtle (Agrionemys horsfieldii).

The morphology and topography of the ciliary ganglia in the midday gerbil and turtle were studied with use of histochemical and histological techniques. The ciliary ganglion of the midday gerbil consisted of two cell agglomerations: the main ganglion and the accessory ganglion. The main ganglion was situated in the orbit and usually closely attached to the nerve for the inferior oblique muscle. The short ciliary nerves arose from the superior end of the main ganglion and reached the orbit. The accessory ciliary ganglion was smaller than the main ganglion. Usually it was attached to short ciliary nerves. The ganglionic neurocytes, 25.97 microm in diameter, were distributed regularly over the entire surface of the main ganglion. They typically had a single clear nucleus. The ciliary ganglion in the turtle formed a characteristic triangular structure on the inferior branch of the oculomotor nerve. The histological examination showed a small number of nerve cells in comparison to the nerve fibres. The neurocytes were placed mainly in the nasal part of ganglion and they had an irregular arrangement. The average diameter of neurons was 23.55 microm. Significant differences in density of ganglionic components in both species were observed. In midday gerbil the cells were densely packed and took up about 80% of a cross-section, while, in the turtle, neurocytes were located mainly in the surface part of ganglion.

The AChE-positive ganglia in the trachea and bronchi of the cat.

The tracheal and bronchial parasympathetic ganglia in the cat were studied using the histochemical-tiocholine method of Koelle and Friedenwald and histological techniques. Intensively stained AChE-positive nerve structures, i.e., ganglia and nerve fibres on the wall of the trachea and bronchi, were observed. The ganglia were situated mainly on the dorso-lateral surface of these organs, but they were also present on the ventral surface. The largest ganglia were found in the vicinity of the vagus nerve branches and on the surface of the tracheal smooth muscle. Numerous ganglia (95-210) of different sizes (40 x 230 microm to 260 x 520 microm) and shapes (spindle, longitudinal, oval, elliptical and multiform) were interconnected by nerve fibres and formed a dense ganglionated plexus. The ganglia forming this nerve structure were located mainly on the level of intercartilaginous spaces. They received the nerve branches from the cervical and the upper thoracic branches of vagus nerve and cervical and upper thoracic segments of the sympathetic trunk. Similar AChE-positive ganglionated plexus containing 28-33 ganglia connected by nerve fibres was observed on the posterior wall of the bronchi. Histological investigations confirmed the presence of fascicles of nerve fibers and nerve cells aggregations in the external membrane of the trachea and bronchi. The ganglia consisted of 2-25 cells on the cross-section. They were located mainly on the level of intercartilaginous spaces and contained (except ganglionic neurocytes, nerve fibres) satellite cells and small blood vessels. All the ganglia had thin connective capsule.

Morphology, topography and cytoarchitectonics of the pterygopalatine ganglion in Egyptian spiny mouse (Acomys cahirinus, Desmarest).

Using the thiocholine method of Koelle and Friedenwald and histological techniques the pterygopalatine ganglion in Egyptian spiny mouse (Acomys cahirinus, Desmarest) was studied. The ganglion was found to be a single irregular cluster of neurocytes, situated on the medial surface of the maxillary nerve. The ganglion is composed of oval, elliptical and sometimes fusiform ganglionic neurones in compact arrangement without a thick connective-tissue capsule.