No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Über das Vorkommen von Muskelspindeln in der Muscularis propria des menschlichen Oesophagus
... The most prominent vagal afferent structures in the muscle coat of the esophagus (and also the rest of the digestive tract) are the so called intraganglionic laminar endings (IGLEs; Berthoud et al. 1997a;Wang and Powley 2000) that were recently identified as sites of low threshold mechanosensory transduction (Zagorodnyuk and Brookes 2000;Zagorodnyuk et al. 2001). In contrast to earlier reports (Asaad et al. 1983;Slawik 1942), muscle spindles could not be found either in the esophageal body or the UES (Bonington et al. 1988;Neuhuber 1987). Also of particular interest is the rather dense vagal innervation of the mucosa in the upper esophagus displaying a variety of distinct terminal structures (Dütsch et al. 1998;Wank and Neuhuber 2001). ...
Understanding the innervation of the esophagus is a prerequisite for successful treatment of a variety of disorders, e.g., dysphagia, achalasia, gastroesophageal reflux disease (GERD) and non-cardiac chest pain. Although, at first glance, functions of the esophagus are relatively simple, their neuronal control is considerably complex. Vagal motor neurons of the nucleus ambiguus and preganglionic neurons of the dorsal motor nucleus innervate striated and smooth muscle, respectively. Myenteric neurons represent the interface between the dorsal motor nucleus and smooth muscle but they are also involved in striated muscle innervation. Intraganglionic laminar endings (IGLEs) represent mechanosensory vagal afferent terminals. They also establish intricate connections with enteric neurons. Afferent information is implemented by the swallowing central pattern generator in the brainstem, which generates and coordinates deglutitive activity in both striated and smooth esophageal muscle and orchestrates esophageal sphincters as well as gastric adaptive relaxation. Disturbed excitation/inhibition balance in the lower esophageal sphincter results in motility disorders, e.g., achalasia and GERD. Loss of mechanosensory afferents disrupts adaptation of deglutitive motor programs to bolus variables, eventually leading to megaesophagus. Both spinal and vagal afferents appear to contribute to painful sensations, e.g., non-cardiac chest pain. Extrinsic and intrinsic neurons may be involved in intramural reflexes using acetylcholine, nitric oxide, substance P, CGRP and glutamate as main transmitters. In addition, other molecules, e.g., ATP, GABA and probably also inflammatory cytokines, may modulate these neuronal functions.
In den meisten neurohistologischen Arbeiten über die Mundschleimhaut überwiegt das Studium der sensiblen Endigungen; die Endigungsweise des Trigeminus tritt in den Vordergrund der Betrachtung, während man von den Einrichtungen des vegetativen Nervensystems nur weniges aus der Literatur erfährt. Seto, Fujii und Ikui (1954) berichten zwar über ein vegetatives Terminalreticulum in der menschlichen Lippe, beschränken aber ihre Untersuchungen auf die Pars cutanea, wo sie eine Fülle sensibler Endapparate beschreiben. Suga (1951) und Abe (1954) erwähnen intraepitheliale Nerven in der Mucosa der Lippe und des Mundes, Ohgaki und Hotta (1953) haben in der Mucosa des Mundbodens beim Menschen nervöse Endknäuel, verzweigte und unverzweigte Enden und Geschmacksknospen beobachtet.
A skeletal muscle is such an obvious example of an effector organ that it generally comes as a surprise to learn that most of the nerve fibres innervating it are sensory. Studies of the composition of cat hindlimb muscle nerves (Boyd and Davey, 1968; Stacey, 1969) have shown that sensory axons account for about two thirds of the total somatic component; most of them are non-myelinated. All the non-myelinated sensory axons, as well as some of the myelinated ones, terminate as free endings on blood vessels and in fat and connective tissue (Stacey, 1969). Some of these function as nociceptors responding to deep pressure or to squeezing the muscle, and compare with similar receptors found in skin. The rest of the myelinated sensory axons supply two types of mechanoreceptor responding to stretch, namely, the tendon organ and the muscle spindle; a few paciniform corpuscles, such as occur more commonly in joint capsules and periarticular tissue; and occasionally one or two of the much larger Pacinian corpuscles. The small muscle fibres that compose the spindles receive their own supply of motor (γ) axons, which on average constitute 43% of the total somatic motor component in cat hindlimb muscle nerves (Boyd and Davey, 1968). The receptor equipment of a cat hindlimb muscle thus receives a very large share (81%) of the total supply of somatic nerve fibres, while the muscle fibres that execute its contractions and constitute the bulk of the organ receive the small remainder as skeletomotor (α) axons.
A un certain stade, dans les foyers d'inflammation aseptique du tissu conjonctif, apparaissent des cellules riches en lments rticuloendoplasmique (cellules rticulo-histiocytaires) ayant certains points de vue des apparences plasmocytaires. A partir de leur rticulum endoplasmique se dveloppent de larges citernes (cisternae) contenu vraisemblement protique. Ce contenu est rejet dans le milieu intercellulaire soit par ouverture des citernes superficielles soit par dislocation de tout ou partie de la cellule. Par ce phnomne assimilable une clasmatose, des citernes sont libres dans le milieu intercellulaire. Elles apparaissent alors comme des vacuoles limites par des membranes riches en ribosomes. On peut rattacher ce processus l'laboration de protines et leur dversement dans le milieu intercellulaire, un moment de l'volution de la raction inflammatoire o la construction de nouvelles cellules et de nouvelles fibrilles ncessite des lments protiques de construction.
The muscular wall of the esophagus of the rat consists exclusively of striated muscle fibers which do not differ from the skeletal muscles of the same animal. These fibres are arranged in two layers running spirally in contrary directions. Between these two layers a ChE-positive myenteric plexus occurs, containing several ganglionic cells at its crossing points. 10 per cent of these ganglionic cells are strongly AChE-positive. The tiny branches of the vagus nerve, passing through the outer muscular layer into the myenteric plexus consist of bundles of unmyelinated as well as myelinated fibres. The terminal branches of the plexus leading to motor endplates are unmyelinated.
The motor endplates are situated in trough-shaped impressions of the surface of muscle fibres. The subsynaptic sarcolemma is richly folded, even in places where there is no overlying synaptic terminal.
There are two kinds of nerve terminals in the motor endplates: (1) Thick terminals abundantly filled with clear synaptic vesicles but also containing a few dense core vesicles. (2) Thin axons containing predominantly granulated vesicles.
The synaptic nerve terminals often come into contact with each other, occasionally forming membrane thickenings at such places.
Wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) was injected into nodose ganglia of rats. In the esophagus and cardia, dense networks of anterogradely labeled fibers and beaded terminal-like arborisations were observed around myenteric ganglia after combined histochemistry for HRP and acetylcholinesterase. The muscularis externa and interna proper were free of label except for a few traversing fibers. Submucosal and mucosal labeling was rather sparse except for the most oral part of the esophagus, where a dense mucosal innervation was found. Control experiments including WGA-HRP injections into the cervical vagus nerve, nodose ganglion injections after supranodose vagotomy, and anterograde [3H]leucine tracing from the nodose ganglion indicated that all labeled fibers in the esophagus and cardia originated from sensory neurons in the nodose ganglion. Electron microscopy revealed that labeled vagal sensory terminals related to myenteric ganglia were mostly large, mitochondria-rich profiles located predominantly on the surface of the ganglia. Specialized membrane contacts connected sensory terminals with other unlabeled profiles possibly derived from intrinsic neurons. The polarity of these contacts suggested the vagal sensory terminals to be presynaptic to intrinsic neurons of the myenteric ganglia. A hypothesis is formulated postulating a mechanoreceptive role for 'myenteric' vagal sensory terminals, providing both the brainstem (via the vagus nerve) and, by synaptic action upon intrinsic neurons, the myenteric plexus with information on tension and motility of the esophagus and cardia.
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.
ResearchGate has not been able to resolve any references for this publication.