Neural apparatus of the wall of the ductus deferens in the dog

While studying the innervation sources of the deferent duct in 10 dogs, 2-3 nerves have been revealed that take their origin at the pelvic neural plexus and approach the duct together with the blood vessels at the pelvic neural plexus and approach the duct together with the blood vessels at the place where it crosses the ureter ("the vascular-neural hilus"). In the experiment performed in 65 dogs the nature of these sources has been revealed. The motor innervation is presented by the nodes of the celiac plexus, of the lumbar and sacral parts of the sympathetic trunk, of the subceliac, gonadal and splanchic pelvic nerves, and the sensitive innervation is multisegmental and is performed by the intravertebral nodes L2-S3. Quantitative investigation of the degenerated neural fibers in the dog deferent duct wall demonstrates that the innervation sources mentioned above participate te a various degree along the course of the organ. In the "hilus" the nerves of the dog deferent duct are divided into the proximal nad distal groups. The proximal group runs towards the prostate and forms a plexus with large loops connected with the neural plexuses of the urinary bladder, the ureter and the prostate. It has small neural nodes. The distally directed nerves run, together with the blood vessels, in the deferent duct towards the epididymis. In the deferent duct wall, adventitila, muscular and mucous neural plexus are found, the cholinergic component prevailing the adrenergic one. The plexuses are somewhat better developed at the beginning of the deferent duct and they are especially pronounced in the ampule. The receptors of the organ's wall are simple, poorly branching.     

Adrenergic innervation of the kidneys in man and various laboratory animals

By means of the neurohistochemical method for slice incubation in 2% solution of glyoxylic acid, innervation of the kidneys of a 57-year-old man after a sudden cardiac death has been investigated, as well as innervation of the kidneys in white rat, rabbit, guinea pig and cat. A rich adrenergic innervation in the organ's blood vessels has been revealed. In particular, adrenergic nervous fibers have been found along the course of afferent glomerular arterioles. Together with innervation of the proximal and distal convoluted tubules, a high density of the terminal adrenergic nervous plexus is revealed along the course of the nephron loops. Adrenergic nervous plexuses of high density are found in the area of the initial part of the urinary excretory pathways and their connection with nervous plexuses of the kidney itself.     

Inter-organ neural communications in the innervation of bronchi and pulmonary circulation vessels

By means of V.P. Vorobiov's preparation in complex of the thoracic cavity organs of persons at various age and sex in fetuses, sources of innervation of bronchi and vessels of the pulmonary circulation have been stated. They make the composition of the cardiac nerves getting off the superior, middle cervical, cervico-thoracic (stellate) and from 3 to 5 thoracic nodes of the sympathetic trunk, superior and inferior cardiac branches of the nervus vagus. Connection between the nerves of the bronchi and vessels of the pulmonary circulation with the cardiac and esophageal nerves and formation of interorganic nervous plexuses are demonstrated. Not always the diaphragmal nerve participates in the innervation of the bronchi and pulmonary vessels. In total preparations and flat sections, elective revealing of the nervous elements with Shiff reagent in M. G. Shubich and A. B. Khodos modification and Gomori thiocholine method, makes it possible to follow connections of the pulmonary veins nerves with the left atrium, intrapulmonary connection of the perivascular and peribronchial plexuses, as well as participation of nervous elements of the pulmonary trunk in innervation of the right ventricle walls. There are multiple vegetative communications participating in innervation of the bronchi and vessels of the pulmonary circulation. The relations of the pulmonary nerves with the nerves of other thoracic organs are very complex; this explains the nature of the repercussive reactions of the lungs after surgical interventions performed in the other organs of the thoracic cavity.     

Adrenergic terminal structures in the mesentery of mammals

This work is devoted to the study of adrenergic terminal structures in the mesentery of mammals (cat, dog). The investigation was performed with the Falck-Hillarp method of catecholamine fluorescence microscopy on total stretch mesentery preparations. The investigation showed that richly developed perivascular plexus constitute the basis of the adrenergic innervation system of the mesentery. In numerous points of these plexuses, single adrenergic fibers or polyaxonal structures are observed to issue into nonvascular areas of the mesentery where after repeated dichotomic division they pass into the preterminal and terminal parts. Being constructed on the principle of extended or restrained arborizations, these innervating structures have a morphological similarity with free sensory nerve endings. In this connection, the question of the possible existence of the sensory (afferent) links in the catecholamine-containing vegetative nerve plexuses is discussed.     

Cholinergic innervation of the human pulmonary circulation

The cholinergic innervation of the pulmonary circulation was studied in man. Both extra- and intrapulmonary branches of the pulmonary artery and vein are provided with a cholinergic of the vein. In the main branches of the pulmonary vessels, the existence of two nerve plexuses, a superficial and a deep one, was observed. The superficial plexus is localized in the outer adventitial layer while the deeper plexus is localized in the adventitial-medial transitional zone. In smaller arteries and veins, the existence of a single plexus (adventitial-medial) was observed. In some specimens, the presence of diffuse masses of acetylcholinesterase (AChE)-positive material or elbow-shaped AChE-positive formations was observed. The nature of these formations as well as the possible functional role of a cholinergic system in the pulmonary circulation are discussed.     

Cross-sectional anatomy of miniature "Shiba" goat]

The anatomical relations of visceral organs and other tissues in the thoracic, abdominal and pelvic cavities of the male miniature "Shiba" goat are illustrated as thirteen semi-diagramatic representations of cross sections.     

Fluorescence histochemical study on regional differences in the sympathetic nerve supply of the choroid plexus from various laboratory animals

Summary The adrenergic nerve supply of the choroid plexus in all four ventricles was studied by the Falck-Hillarp histofluorescence technique in nine different species, and the noradrenaline concentration in whole plexus tissue was determined by a radioenzymatic method. The nerve density was usually in the order: third > lateral > fourth ventricular plexuses. Plexuses of the pig and cat possessed the largest number of nerves; the innervation was intermediary in the baboon, guinea-pig, rat, rabbit and hamster, whereas only few fluorescent nerves were found in the cow and mouse plexuses. Sympathetic denervation showed an ipsilateral supply from the superior cervical ganglia to the lateral plexuses and a mixed contribution to the midline plexuses. The total noradrenaline concentration varied between 0.10 and 0.73 ng per mg protein.     

Intrinsic Innervation of a Reptilian Esophagus (Podarcis hispanica)

We study the esophagus of Podarcis hispanica through different methods to clarify the structure and affinities of its wall innervation. The acetylcholinesterase method reveals cholinesterase activity in two submucosal nervous plexuses, with an increasing degree of structural complexity in the reptilian esophagus, compared with amphibians. Noradrenergic innervation, detected through fluorescence induced by formol, widely spreads its network in both the myenteric and submucosal plexuses (around the blood vessels in the external submucosal plexus, and to the glandular lamina propria in the inner submucosal plexus). Immunohistochemistry for vasoactive intestinal peptide shows a widespread innervation, with neurons clustered in ganglia and also scattered through the VIPergic network, only at the myenteric plexus. Immunohistochemistry for substance P shows a rich innervation along the entire wall of the esophagus, more concentrated in its caudal region, around the blood vessels. Electron microscopy shows the enteric neuronal ultrastructure and its relationship with the esophagus wall.     

Neurohistological observations on the oesophageal innervation of rabbit

Summary The vegetative, motor, and sensitive innervation of the oesophagus of rabbit was studied by means of several neurohistological techniques. A great deal of vegetative and somatic nervous formations were found and described within the various segments of the organ; namely at level of the cervical, thoracic, prediaphragmatic, and abdominal oesophageal tracts. In particular, isolated and grouped ganglion cells, interstitial and associative neurons, free nervous terminations, and an amyelinated subepithelial network sending delicate fibrils to the basal layers of the impending epithelium were described. The vegetative nervous component is organized into an extramural oesophageal plexus, and into an intramural one. The numerous motor endplates lying on the striated muscle fibres show different forms and several other structural pecularities. The sensitive terminations are represented by simple and non-capsulated Ruffini's corpuscles contained within the submucous connective tissue. The possible functional correlations of these morphological findings are discussed.This study was in part supported by a grant from the Italian C. N. R.     

Intrinsic and extrinsic innervation of the amphibians esophagic myenteric plexuses

The innervation of Rana ridibunda esophagus myenteric plexuses has been studied by the following methods: demonstration of cholinesterase activity; FIF method for catecholamines; immunohistochemistry for VIP, SP and SOM, and conventional electron microscopy. The cholinergic innervation is important in the esophagus wall where, in addition to the well known extrinsic component, there is a rich intrinsic plexus with cells and fibres widely distributed. The esophagus, together with the intestine, are the Rana gut portions where the adrenergic component is more broadly expressed. The adrenergic innervation seems to be almost entirely of extrinsic origin. We have shown that, for the tested peptides, there is an intrinsic innervation represented by VIP, SP and SOM like plexuses. We do not discard nonetheless an extrinsic component. The ultrastructure reveals the morphological characteristics of the enteric neurons as well as the fine inter-relationships between the nervous elements and the functional components of the esophagic wall.     

Intrinsic innervation of the gall bladder in the dog.

The gall bladder of eight dogs 3 months old were extracted and studied by the Holme's and Gross-Bielschowsky techniques. The nerves were found to form an extensive network within the wall of the gall bladder. However, 5 plexuses were identified and their arrangement was similar to that in the wall of the intestine. Nerve cells were only found in relation with the myenteric plexus. Moreover, knob-like terminals and circular type of nerve endings were noticed on the muscularis. The findings of the intrinsic innervation of the gall bladder of the dog were compared with that of man, monkey and guinea pig and the significance of that innervation was discussed.     

The intermediate nerve and its place in the system of cranial nerves

The intermediate nerve (IN) in embryogenesis of man, cat and white rat is formed similarly. From the common with the VIII cranial nerve anlage the geniculum node, the vestibular and cochlear ganglia are emerged. A separated root of the IN connects the geniculum node with the nuclei, situating in the CNS. From the geniculum node main branches of the IN get off: the greater petrosal nerve and the cord of the tympanum, its fibers in the temporal bone canal run in the facial nerve trunk. In the periphery the IN branches unite with other cranial nerves, make connections with branches of vegetative (parasympathetic) ganglia and plexuses. They spread along a large territory, forming a system of parasympathetic innervation in the area of the head and ensuring with specific nervous apparatuses the gustatory organ. It is expedient to select the IN into an independent cranial nerve and confirm it the number of the regular pair.     

Muscles of the pelvic outlet in the fowl (Gallus gallus domesticus) with special reference to their nerve supply.

The manner of innervation of the pelvic outlet muscles in fowl (Gallus gallus domesticus) was examined in detail in four male pelvic halves. The segmental arrangement of the nerve supply in the sacral and pudendal plexuses was compared to that of Lacertilia and Urodela as a basis for a morphological analysis of the pelvic outlet muscles. From the viewpoint of innervation, the pelvic outlet muscles of fowl are classified into two groups: a sphincter muscle group and a levator muscle group. These two groups are closely related to the ventral muscles of the pelvic limb. In contrast to the morphology of pelvic outlet muscles in lacertilians, in fowl the caudal muscle element does not contribute to the formation of these muscles.     

Development of the blood-brain barrier to horseradish peroxidase in the chick embryo

Summary The development of the adrenergic sympathetic innervation of the rabbit choroid plexus system was studied prenatally and up to two months after birth by a combination of fluorescence histochemistry (formaldehyde and glyoxylic acid methods) and quantitative enzymatic determinations of noradrenaline. The first signs of adrenergic nerves are found in the plexus of the third ventricle within the first day after birth. Fluorescent fibres subsequently appear in the choroid plexuses of the lateral ventricles (five days post partum) and the fourth ventricle (two weeks post partum). During the following development nerve fibres grow along blood vessels to form a plexus located between small vessels and the overlying epithelium. The nerve plexus, with varicose axon terminals, is fully developed at three weeks post partum, and maturation is then established by an increase in the number of terminals within the network of axons. There is a good agreement between (a) the development of the fluorescent nerves and histochemically visible adrenergic innervation, and (b) the tissue level of noradrenaline in the various choroid plexuses. Against the background of available information on the development of the secretory functions in choroid plexus, it is concluded that possibilities for a sympathetic neurogenic influence on the formation of cerebrospinal fluid exist already a few weeks after birth.     

Quantitative analysis of the density and pattern of adrenergic innervation of blood vessels

Summary Automated quantitative image analysis (QIAF) was used to measure and compare the adrenergic nerve plexuses of 4 blood vessels from the guinea pig, demonstrated by glyoxylic acid fluorescence (GAF). The results showed considerable quantitative variation of plexus density, size of bundles, and numbers of varicosities. A range of alternative procedural and anatomical sources of variability were investigated and assessed. The carotid artery was found to have a dense plexus with more nerves than that of the mesenteric artery; the mesenteric vein and abdominal aorta had sparse plexuses. The carotid artery plexus, despite the density of its nerves, possessed only half the number of varicosities of the mesenteric artery plexus. This sparse varicosity population was shown to have a similar density to the varicosities demonstrated by QIAF in the scattered nerves of the mesenteric vein and abdominal aorta. QIAF confirmed visual estimates of adrenergic plexus density, and was able to demonstrate less obvious differences of nerve density and size, and varicosity populations, between the different plexuses studied. The method is applicable to stretch preparations and transverse sections of many adrenergically innervated tissues.     

Nervous control of intestinal fluid transport: physiology and pathophysiology

1. The enteric nervous system (10(8) neurones in man) consists of the myentric plexus, the submucosal plexus and other minor plexuses. Eighteen different chemicals are candidates for the role of neurotransmitters in the ENS. 2. The ENS together with the autonomic nervous system and the hormonal system controls gut epithelial transport systems.     

Innervation of the mucosa of the small intestine of laboratory animals. I. Architecture, light microscopic structure and histochemical differentiation

1. The small intestine mucosa has a dense and differentiated innervation. The most dense nerve plexuses are contained in the villi. Each tubular gland is surrounded by a rope-ladder-like plexus, mostly developed in the lower and upper third. 2. According to our observations most of the axons in the mucosa are cholinergic. Cholinergic and adrenergic axons take part in the innervation of the glands. Moreover enterochromaffine cells can be innervated for instance sympathetically. Intraepithelial axons could not be found.     

Avian enteric nerve plexuses

Summary The enteric nerve plexuses of the domestic fowl (Gallus domesticus) were investigated in sections and stretch preparations by means of the cholinesterase and glyoxylic acid fluorescence histochemical techniques. Cholinesterase-positive and varicose and non-varicose fluorescent nerve fibres were distributed at all levels of the gut in myenteric, submucosal, muscle and mucosal plexuses, and in a perivascular plexus. The density of the innervation and the detailed distribution of the nerves varied in different parts of the intestinal tract. All nerve plexuses appeared to be best developed in the rectum. Whereas the circular muscle coat contained a substantial number of nerves at all levels of the gut, the longitudinal coat was well innervated only in the rectum. The major portion of the mucosal plexus appeared to be associated with the intestinal glands. The nerve cell bodies were restricted to the myenteric and submucosal plexuses and were mainly cholinesterase-positive. Fluorescent ganglion cells were not observed. Pretreatment of stretch preparations with NADH: Nitro BT to stain ganglion cells showed that the majority of the cells were surrounded by a meshwork of fluorescent varicose fibres, although none of the fibres appeared to be associated with individual cells. The perivascular plexus was mainly associated with the arteries. The functional significance of the innervation is discussed.We would like to thank the British Council for financial support for Mr. H.A. Ali     

The origin and distribution of adrenergic nerve fibres in the guinea-pig colon

Summary A detailed study of the origin and distribution of sympathetic fibres in the distal colon of the guinea-pig has been made using the fluorescent histochemical method for localizing catecholamines. The extrinsic adrenergic fibres of the colonie sympathetic nerves follow the inferior mesenteric artery and its branches to the colon. Some of the extrinsic adrenergic fibres are associated with the parasympathetic fibres of the pelvic nerves near the colon. Complete adrenergic denervation follows the removal of the inferior mesenteric ganglion or the destruction of the nerves running with the inferior mesenteric artery.No fluorescent fibres, other than those associated with blood vessels, were observed in air-dried stretch preparations of the isolated longitudinal muscle. However, a substantial number of varicose, terminal fibres, not associated with blood vessels, were observed in the circular muscle. Some varicose fibres, apart from those associated with ganglion cells, were observed in the myenteric plexus. These fibres were seen in the bundles of nerves running between the nodes of the plexus and also as single fibres which branched from the plexus to end in areas free of ganglion cells.Three plexuses of adrenergic nerve fibres have been distinguished in the submucosa: a dense plexus of terminal fibres innervating both the veins and arteries; a plexus consisting of innervated nodes of ganglion cells, connected by bundles of fluorescent and non-fluorescent nerves; and a plexus of varicose and non-varicose fibres, which is not associated with ganglion cells. Some groups of ganglion cells in the submucosa were without adrenergic innervation.A plexus of varicose fibres forms a meshwork in the lamina propria of the mucosa. The muscularis mucosae is sparsely innervated. Most of the blood vessels in the mucosa are not associated with adrenergic fibres.