Fine Structure of Nerve Endings and Junctions in the Superior Cervical Ganglion of the Camel (Camelus dromedarius)

The superior cervical ganglion of the one humped camel was studied using an electron microscope. The ganglion contained presumptive cholinergic endings, presumptive aminergic endings, and presumptive sensory endings. Presumptive cholinergic endings contained numerous small clear vesicles, a few large dense-cored vesicles, and mitochondria. They frequently made synaptic junctions with dendritic processes and, occasionally, with axons in transit. There were few presumptive aminergic endings and they were characterized by a mixed population of dense-cored vesicles and clear vesicles. They only made synaptic junctions with axons in transit. Presumptive sensory endings were characterized by numerus slender mitochondria and had no synaptic junctions of any kind. Symmetrical membrane thickenings (puncta adherens) were frequently encountered in this study, usually between dendritic processes and other neuronal elements of the superior cervical ganglion.     

Structure of the Carotid Sinus of the Dromedary Camel (Camelus dromedarius)

The morphology of the terminal segment of the common carotid artery of the camel was studied. It was found that this artery terminated by giving off a patent internal carotid artery and continuing as the external carotid artery. A presumptive carotid sinus was present at the region of origin of the internal carotid. Similar to that of other mammals, the carotid sinus of the camel was characterized by a comparatively thin vascular wall rich in elastic fibres. With the electron microscope, free (non-encapsulated) afferent endings, efferent endings, encapsulated axons and bundles of unmyelinated and myelinated nerve fibres were found in the wall of the presumptive carotid sinus. The free afferent endings closely resembled baroreceptor endings of the carotid sinus of other mammalian species in their mitochondrial content and the presence of abnormal organelles such as lamellar bodies, vesicular mitochondria and dense bodies. They were regarded as slowly adapting baroreceptors. The presumptive efferent endings were considered adrenergic whereas the encapsulated axons were thought to be the proximal parts of encapsulated sensory nerve endings.     

Structure of bovine fungiform taste buds and their immunoreactivity for gustducin

The taste buds of bovine fungiform papillae were studied by light and electron microscopy using both histological and immunohistochemical methods. The taste buds existed in the epithelium of the apical region of the papillae. By electron microscopy, two types of taste cells, namely type I and type II cells, could be classified according to the presence of dense-cored vesicles, the cytoplasmic density and the cell shape. Type I cells were thin, had an electron-dense cytoplasm containing dense-cored vesicles, and possessed long thick apical processes in the taste pore. Type II cells were thick, had an electron-lucent cytoplasm containing many electron-lucent vesicles, rather than dense-cored vesicles, and possessed microvilli in the taste pore. Immunohistochemical staining with an antiserum against gustducin was investigated by both light and electron microscopy using the avidin-biotin complex (ABC) method. Some, but not all, of the type II cells exhibited gustducin immunoreactivity, whereas none of the type I cells showed any immunoreactivity.     

Ultrastructural Changes in Nervous Elements associated with the Granular Cells of the Common Carotid Artery of the Domestic Fowl after Distal Vagal Ganglionectomy

Intramural granular cells of the left and right common carotid artery of the domestic fowl were examined with the electron microscope after left distal vagal ganglionectomy. The vast majority of the nerve fibers and endings associated with the granular cells of the left common carotid artery degenerated rapidly after ispilateral ganglionectomy, indicating that they are derived from the left vagus. On the other hand, left distal vagal ganglionectomy resulted in transformation of the intramural granular cells of the right common carotid artery and the few nervous elements associated with them, into a typical chemoreceptor tissue. This tissue was made up of small granule (60 -120 nm) containing cells associated with many nerve fibers, nerve endings and fenestrated capillaries. The nerve endings were of two types; presumptive afferent endings and adrenergic efferent endings. Both types of endings made synaptic junctions with the granular cells.     

The Poll Glands of the Dromedary (Camelus dromedarius): Ultrastructural Characteristics

The poll glands of the camel are tubuloalveolar glands. They consist of lobules separated by interlobular connective tissue. Adrenergic axons and blood vessels including fenestrated capillaries are present in the intralobular connective tissue in close proximity to the secretory cells. The prominent features of the secretory cell cytoplasm are many mitochondria, smooth endoplasmic reticulum, and many vesicles in various secretory stages.
It is concluded that the secretory cells have apocrine as well as merocrine modes of secretion. The glands may have the ability to uptake hormones and concentrate them. Additional work is needed before considering these glands as steroid-secreting glands.     

Spontaneous pinealoma in a male Crj:CD (SD) IGS rat

A pinealoma (benign) was found in a 61-week-old male Crj:CD (SD) IGS rat. The neoplasm was located between the cerebral hemispheres and the cerebellum. Histologically, the tumor cells consisted of two cell types: large, pale-staining cells and small dark-staining cells. A fibrovascular stroma divided the tumor cells into incomplete lobules or nest structures. Relatively numerous mitoses were noted in the tumor cells. Ultrastructurally, the tumor cells contained dense-cored vesicles, approximately 120 nm in diameter.     

Morphology and innervation pattern of the feline urogenital junction

The feline urogenital junction is situated between the extratesticular rete and the spacious initial segments of the efferent ductules. The rete epithelium is cuboidal to low columnar. The rete cells forming the junction rest on a wavy basal lamina, display deep mutual invaginations, possess central nuclei with several infoldings and form a distinct border with the columnar epithelial cells of the initial segments of the ductuli efferentes. The epithelium of the initial segments is composed of ciliated cells and non-ciliated principal cells. The latter are the dominating type and characterized by an apical brush-border and a supranuclear endocytotic apparatus. The stroma of the extratesticular rete contains an abundance of collagen whereas contractile cells are here generally absent. In contrast, the initial segments of the efferent ductules are surrounded by elastic fibres and a layer of contractile cells. All nerves for the feline urogenital junction come from the nervus spermaticus superior. In the epididymal head, small nerve bundles deviate into the septa between the ductules. Single fibres establish a dense network within the muscular coat of the ductuli. At the transition to the extratesticular rete, this network ends abruptly. Nerve fibres in the confines of the rete are associated with blood vessels or proceed to the testicular interior, but establish no relationships with the rete epithelium or the myofibroblasts of the mediastinum. The nervous network in the walls of the efferent ductules and their initial segments is not only composed of sympathetic but also parasympathetic, non-myelinated fibres. Particularly noteworthy is the abundance of calcitonin gene-related peptide (CGRP)- and substance P (SP)-containing axons around the initial segments. Both neuroproteins are consistent markers for sensory neurones. Taken together, it can be assumed that the entry of seminal fluid and spermatozoa into the efferent ductules is controlled by a regulatory nervous chain provided with afferent and efferent components.     

The Evidence of Carotid Body in the Carotid Rete of the Shiba Goat

The carotid body was found in/on the cavernous sinus of the carotid rete of the Japanese miniature Shiba goat by light and electron microscopies. The carotid body-like aggregated cell group consisted of two types of cells arranged in the lobule. The first type contained membrane-bound granular vesicles; these cells resembled to the type-I cells in the carotid body. The second type contained no cytoplasmic vesicles, and were located in the periphery, investing the type-I cells. These features appear to be consistent with those of the type-II cells in the carotid body. The nerve ending showed two peculiar features in the intercellular space of type-I cells. The clear vesicle-containing nerve ending showed a structural feature indicative of efferent synapsis. The small granular vesicle-containing nerve ending has been described as a baroreceptor-like ending by VERNA (1979). All of these features are typical characteristics of the carotid body.     

Angioarchitecture of the Branchial Arterial System of Carp (Cyprinus carpio L.)

The arterial system of the gills of carp and its histological structure were studied light and electron microscopically by making Mercox or Neoplane Latex corrosion cast preparations. Four pairs of afferent and efferent branchial arteries, and a pair of afferent and efferent pseudobranchial arteries were identified in the branchial arterial system. The 1st and 2nd afferent branchial arteries are given off directly from the ventral aorta, and the 3rd and 4th afferent arteries originate from their common trunk, which is branched off from the ventral aorta caudal to the origin of the former branchial arteries. Numerous afferent filamental arteries are connected to the lamellar blood capillary networks in the gill lamellae via afferent lamellar arterioles, and efferent filamental arteries followed the efferent lamellar arterioles are converged into four efferent branchial arteries that are connected to the dorsal aorta. To the pseudobranchia, afferent pseudobranchial arteries are connected with the ventral branches of the 1st efferent branchial arteries to provide arterial blood to the organ through the afferent mandibular arteries. Afferent pseudobranchial lamellar arterioles originating from the afferent pseudobranchial filamental arteries are connected with the blood capillary networks in the pseudobranchial lamellae, and blood in the capillary networks is drained into the efferent pseudobranchial filamental arteries via 2-4 pseudobranchial lamellar arterioles. Branches of the efferent pseudobranchial filamental arteries are connected with the arteries to the eyeballs and provide blood to choroid of the vascular tunic of them. Pseudobranchial cells surrounding lamellar capillaries in the pseudobranchia are furnished with abundant mitochondria and tubular structures, and the histological findings suggest the cells may share an ability to exchange physiological materials between the cells and the blood in the capillary networks of pseudobranchia.     

Calretinin immunoreactive nerve endings in the trachea and bronchi of the rat.

Nerve endings showing calretinin immunoreactivity were examined in the lower respiratory tract of the adult rat. Tree-like nerve endings were immunostained in the tracheal and bronchial smooth muscle layer. The endings that arose from thick nerve fibers and formed corpuscles composed of many arborized nerve terminals. A few of the nerve endings were also observed in the lamina propria of the tracheal mucosa, close to the epithelial layer. Immunoelectron microscopy revealed that the immunoreactive terminals were filled with mitochondria and scattered among the intermuscular collagen fibrils. Schwann cell sheath and collagen fibrils were intercalated between the smooth muscle cells and nerve endings. The calretinin immunoreactive nerve endings observed in the present study seem to be slowly adapting stretch receptors.     

An Ultrastructural Study of Nerve Cell Bodies in the Carotid Body and Common Carotid Artery of the Domestic Fowl

The right and left carotid body and carotid baroreceptor zone of six adult domestic fowls were examined. Nerve cell bodies were found in nine of the twelve carotid bodies and in ten of the twelve carotid baroreceptor zones. They showed the general ultrastructural features of autonomic neurons. Nerve cell bodies in both locations contained intranuclear inclusion bodies and cytoplasmic dense cored vesicles. A few presumptive adrenergic endings, and dendritic processes were associated with nerve cell bodies in the carotid body. Large numbers of presumptive adrenergic endings and presumptive cholinergic endings, and dendritic processes were associated with nerve cell bodies in the carotid baroreceptor zone. The possible identity and function of these nerve cell bodies are discussed.     

Total and Differential Leucocyte Counts and Lymphocyte Subpopulations in Lymph, Afferent and Efferent to the Supramammary Lymph Node, During Endotoxin-Induced Bovine Mastitis

Leucocyte trafficking in afferent and efferent mammary lymph and the supramammary lymph node in cows was examined during 4 h after intramammary infusion of endotoxin from Escherichia coli. Total and differential leucocyte counts were measured in milk, blood and lymph. The proportions of CD4(+), CD8(+), major histocompatibility complex (MHC) class II(+) and IgM(+) lymphocytes were examined in the lymph and lymph node. At post-infusion hour (PIH) 4, the flow rates of both lymph fluids had increased approximately eightfold. Total leucocyte concentration increased in afferent lymph, but decreased in efferent lymph. Neutrophils increased in afferent lymph at PIH 2 and in efferent lymph and milk at PIH 4. The predominant cell type in afferent lymph shifted from lymphocyte to neutrophil while lymphocyte was still at PIH 4 the predominant type in efferent lymph. Among the lymphocytes, B cells were predominant in afferent lymph and lymph node at PIH 4 while T cells, mainly CD4(+) cells, were predominant in efferent lymph both at PIH 0 and PIH 4. The CD4 : CD8 ratio was higher in efferent lymph and the challenged lymph node than in afferent lymph and the control node, respectively. There was a significant difference in proportions of each lymphocyte subpopulation except for IgM(+) cells, between afferent and efferent lymph after infusion. According to the results, there was already during the first hours of the immune response, a non-random trafficking of neutrophils and lymphocyte subpopulations resulting in a changed distribution of cells in afferent and efferent lymph and a difference in lymphocyte reactivity between the two lymph fluids.     

Microscopic characteristics of genital end bulbs in the penis of bulls

Light microscopic sections of Epon-embedded bull penis were examined for nerve endings. Tissue was taken from the dorsal midline of the glans penis and from the free portion of the penis in 6 mature bulls. Genital end bulbs were identified in both regions of the penis and were located from 1 to 500 micron beneath the epithelium, with most end bulbs concentrated next to the epithelium in the glans penis. Occasionally, end bulbs were found within nerve trunks. Other encapsulated endings were not seen. Ultrastructural correlation of the light and electron microscopic appearance of spherical end bulbs and elongated end bulbs indicated that their structure was identical. Two to 6 neurites filled with mitochondria were surrounded by several layers of thin cytoplasmic lamellae. The lamellae were characterized by pinocytotic vesicles, microtubules, and a scant basal lamina. A capsule of differing thickness enclosed the end bulbs. Fewer capsular layers surrounded more superficially located end bulbs. Near the epithelium, there were gaps in the capsule. Nonmyelinated fibers were seen within end bulbs and between end bulbs and the epithelium.     

Normal ultrastructure and histochemical characteristics of canine lacrimal glands

Lacrimal glands of 12 dogs free of ocular disease were examined to determine the normal structure of these glands. The glands consisted of tubuloacinar cells that ultrastructurally and histochemically were of a single type of secretory cell in the tubules and possibly 3 types of secretory cells in the acini. The tubular epithelium contained homogenous electron-dense granules that stained as neutral glycoconjugates (periodic acid-Schiff positive and Alcian blue and high iron diamine negative). The predominant acinar cells contained granules of lesser electron density than those of the tubules, and stained as sialomucin (Alcian blue [pH 2.5] and periodic acid-Schiff-positive, and high iron diamine-negative). A second type of acinar cell was in peripheral lobules that ultrastructurally and histochemically appeared like lipid granules (positive with oil red O and osmium tetroxide). Ultrastructurally, a third type of acinar granule was finely granular, electron-lucent, and frequently coalesced. It was not readily apparent whether the latter was an artifact, a stage in the maturation of the sialomucin granules, or a third type of acinar granule. Individual acinar cells usually had a predominance of 1 granule type, but greater than 1 granule type could be found in some cells. The basal surfaces of the acinar, tubular, and ductal cells were incompletely ensheathed by myoepithelial cells. Plasma cells, lymphocytes, mast cells, endothelial cells, fat cells, and Schwann cells composed the cellular elements of the interstitium. Lymphocytes, mast cells, and nerve endings also were found in the parenchyma.     

The fine structure of the nucleus of the hypoglossal nerve of sheep and goats]

In the small domesticated ruminants the nucleus of the hypoglossal nerve is situated in close relationship to the median line in the middle of the elongated medulla. The nucleus is divided by the obex into a rostral and a caudal portion. In the sheep, four distinct subnuclei can be recognized, whereas in the dwarf goat great variations in the arrangement of cell groups exists. In both animals large and medium sized neurons are observed. The large neurons are characterized by densely packed small organelles. The medium sized neurons vary between a pale and an electron dense type. According to the size and morphology of the vesicles three types of synaptic contacts can be differentiated. Synapses of type 2 contain clear round and flattened vesicles and are partially accompanied by subsurface cisterns.     

Structural and ultrastructural characteristics of interrenal gland and chromaffin cell of matrinxã, Brycon cephalus Gunther 1869 (Teleostei-Characidae)

This work presents the structure and ultrastructure of the interrenal gland and chromaffin cells, as well as the morphology of the head kidney of Brycon cephalus. The head kidney is composed of fused bilateral lobes located anterior to the swim bladder and ventrolateral to the spinal column. The parenchyma revealed lympho-haematopoietic tissue, melano-macrophage centres, interrenal gland and chromaffin cells. The interrenal gland consisted of cords or strands of cells grouped around the posterior cardinal vein and their branches. Chromaffin cells are found in small groups, closely associated with the interrenal gland and/or under the endothelium of the posterior cardinal vein. So far, the ultrastructural analysis has revealed only one interrenal cell type which contained abundant smooth endoplasmic reticulum and numerous mitochondria with tubulo-vesicular cristae, characteristic of steroid-producing cells. Two types of chromaffin cells were observed. The first type was characterized by the presence of vesicles with round, strongly electron-dense granules, which were eccentrically located. Such cells were interpreted as noradrenaline cells. Meanwhile, cells which contained smaller vesicles and electron-lucent granules, with a small halo separating the granule from the vesicular limiting membrane, were identified as adrenaline cells.     

兔减压神经的纤维成分—HRP法

艇ＨＲＰ法对兔减压神经进行了研究，标记的传入神经元绝大多数位于迷走神经结状节尾侧半部偏一侧，少数见于颈静脉神经节，其中枢突标记终末见于延髓闩以上的孤束核内侧部，腹侧部以及迷背核内。在颈前节也出现标记细胞，表明减压神经中也含有起源于 前节的交感节后纤维成分。主动脉压力感受器有经减压神经来的感觉神经交感节后神经纤维支配。提示减压神经是含有一般内脏传入和一般内脏传出纤维的混合神经，为研究心血管生理提供了     

Coordinated host defense through an integration of the neural,immune and haemopoietic systems

Interactions between the neural and immune systems exist through humoral factors operating via the hypothalamic-pituitary-adrenal axis and cytokines acting over a relatively long distance. Anatomical evidence also suggests direct, hard-wired pathways of interaction and control through innervation of lymphoid organs and peripheral sites involved in host defense, including the thymus, spleen, lymph nodes, and skin. Recent evidence has demonstrated: 1) neural control of the bone marrow haemopoietic system, 2) interactions between peripheral nerve endings in the skin and epidermal Langerhans cells, and 3) peripheralization of leukocytes in the initial stages of stress. This leads us to propose that the nervous system is involved in host monitoring and coordination of host defense systems. If the brain is to have appropriate control of host defense mechanisms it must have: (a) afferent inputs monitoring host defense status, (b) efferent control pathways that modulate primary reactions to infection and damage, (c) efferent activation pathways to the myeloid defense system while the specific, lymphoid immune system is activated, and (d) inhibition of the proliferative lymphocytic response if the infection has been dealt with. We are investigating whether such a model, which allows for control and coordination of both the initial myeloid defense system and of the acquired immune response, is observed in mammals.     

Oocyte ultrastructural characteristics in camel (Camelus dromedarius) primordial to large antral follicles

This study was conducted to describe in detail the ultrastructural features and morphological characteristics of camel oocytes from preantral follicles in relation to the sequential stages of follicular development and also for oocytes from antral follicles in relation to their diameter. Camel oocytes from primordial, primary, secondary and also early to late antral follicles were processed and examined by light and transmission electron microscopy. Primordial follicular oocytes were characterized by a layer of flattened granulosa cells around and also eccentric nucleus and few cytoplasmic organelles in the peripheral region. Up to the secondary follicle stage, flat cells were replaced by cuboidal granulosa cells and their number increased and also an increase in the number of organelles such as vesicles, mitochondria and endoplasmic reticulum was observed. In the early antral stage, the formation of zona pellucida, appearance of microvilli and pleomorphic mitochondria was seen and the nucleus was dislocated to the peripheral region. During final growth phase, the extent of endoplasmic reticulum, vesicles and mitochondria increased, the number of lipid droplets decreased and cumulus cell process endings (CCPE) were observed. In conclusion, the growth of camel oocyte is associated with progressive increase in the number of mitochondria, endoplasmic reticulum, Golgi complexes and cytoplasmic vesicles as well as decrease in the number of lipid droplets and the nucleus migration from an eccentric in preantral to a peripheral location in antral follicles.     

Effects of the adjuvant DEAE-dextran and Staphylococcus aureus on the lymph pathways and filtering capacity of popliteal lymph nodes in sheep

The effects of subcutaneous injections of the adjuvant DEAE-dextran and, or killed Staphylococcus aureus on the structure of the lymph pathways of popliteal lymph nodes in sheep were examined using light and electron microscopy and Microfil casts. Dextran with or without killed S aureus caused significant changes in the lymph pathways both within the node and outside it. However, killed S aureus alone did not. The changes included anastomoses among afferent lymph vessels and between afferent and efferent lymph vessels; proliferation of vessels around the node; joining of parts of the capsule and trabeculae to adjacent parenchyma with loss of parts of the subcapsular and trabecular sinuses; enlargement of medullary sinuses; and reduction of the number of reticular processes in sinuses throughout the node. These changes were accompanied by a reduced ability of the node to filter chicken red blood cells labelled with chromium-51 which were injected into an afferent lymph vessel.