Autonomic innervation of the nasal mucosa

The nasal passages play a crucial role in the protection and functioning of the lower airways. Consequently the nerve supply of the nasal mucosa is extensive, which is related to an immediate and adequate reaction upon a variety of external and internal stimuli. A brief review of the present knowledge on nasal autonomic innervation and pharmacology will be given. There is special attention to more advanced methods, such as radioligand receptor binding techniques, which might augment our insight in the significance of the nervous system in nasal (patho)physiology. Furthermore data on the secretory activity of the nasal glands in the rat and its neural regulation will be accentuated.     

Electron microscopy findings in the nasal mucosa of a patient with stenosis of the nasal vestibule

The nasal mucosa humidifies, warms and filters inspired air before it passes to the lower respiratory tract. In order to maintain the physiological activity of the respiratory epithelium, a certain amount of airflow is required. This report describes electron microscopy findings in the nasal mucosa of a patient who had decreased airflow through the nose due to stenosis of the nasal vestibule. Electron microscopic examination of the nasal mucosa revealed stratified squamous epithelium composed of markedly degenerated cells. The findings of abnormal mucosal structure highlight another negative consequence of nasal obstruction in addition to abnormal physiological function of the nose. The negative impact of diminished airflow on the nasal mucosa should be considered in any case where the patient has a condition that can lead to partial or total loss of airflow through the nose.     

Autonomic innervation of interstitial cells in the nasal respiratory mucosa

We analyzed the microscopic innervations of the pars respiratoria of the nasal mucosa in humans, cats, and rabbits. To this end, the techniques of Jabonero, Champy-Maillet, and Koelle-Friedenwald were employed to detect specific acetylcholinesterase activity. The supremum colli ganglion was also removed from cats in order to observe any tissue changes produced. Using our histochemical techniques, we were able to demonstrate for the first time that Cajal's interstitial cells in the nasal mucosa are acetylcholinesterase-positive. These cells also appear to be totally integrated into the structure of the terminal vegetative neural formations. Additionally, the fibers surrounding these cells were found to show early degeneration after experimental cervical sympathectomies had been performed.     

Autonomic innervation of interstitial cells in the nasal respiratory mucosa

Summary We analyzed the microscopic innervations of the pars respiratoria of the nasal mucosa in humans, cats, and rabbits. To this end, the techniques of Jabonero, Champy-Maillet, and Koelle-Friedenwald were employed to detect specific acetylcholinesterase activity. The supremum colli ganglion was also removed from cats in order to observe any tissue changes produced. Using our histochemical techniques, we were able to demonstrate for the first time that Cajal's interstitial cells in the nasal mucosa are acetylcholinesterase-positive. These cells also appear to be totally integrated into the structure of the terminal vegetative neural formations. Additionally, the fibers surrounding these cells were found to show early degeneration after experimental cervical sympathectomies had been performed.     

Sensitive innervation of the nasal mucosa: current concepts

Sensitive innervation of the nasal fossae by the trigeminal nerves is not a simple passive system of information transmission, but also plays a considerable role in nasal physiology. An antidromic transmission mechanism is in fact added to the conventional centripetal transmission, leading to the release of neurotransmitters (P-substance and C.G.R.P.) at the level of the neuronasal nerve endings. These substances can cause inflammation and vasodilatation (sub-mucosal and perivascular) in certain sites of the 5th nerve, and stimulate the second parasympathetic neurone at the level of the sphenopalatine ganglion. Such phenomena, when they extend beyond physiology, can be the source of local pathology (rhinitis) or loco-regional pathology (headaches).     

Electron microscopic studies of the rabbit nasal mucosa after short-term application of naphzoline nitrate

BACKGROUND: Vasoconstricting nasal drops are applied frequently. Especially early ultrastructural alterations of the vessels were not examined up to now in animal models. Our goal was the systematic investigation of the submucosal vessels and the epithelium after topic application of naphazoline nitrate (Privin) in an animal model. METHODS: Three times daily over 6 days 3 ml of 0.1% naphazoline nitrate solution (Privin) were instilled into the right nasal cavity of 5 rabbits. At the 7th and 14th day an incisional biopsy of the lower nasal turbinate was carried out in ketamine/rompun anesthesia. RESULTS: In the naphazoline group the capillaries showed an edematous endothelium with narrowed lumina. Thrombosis of the arterioles were frequently observed. The more cubic epithelial cells had deciliated areas with microvilli. Venules, submucosal glands and the surrounding connective tissue was normally configurated. Analogous findings were also observed after 2 weeks. CONCLUSIONS: The disturbance of the microcirculation shows impressive endothelial alterations. These structural changes can result in nonreversible mucosal damages. A regeneration time of more than 1 week is assumable. Our results should be considered critically in order to prevent damages of the nasal mucosa.     

Scanning electron microscopy of the nasal glands and vessels

Summary The trypsin-HCl method of Uehara was applied to the respiratory nasal mucosa of rats and guinea pigs, and the stereoscopic surface view of the nasal glands, vessels, and associated nerve fibers were observed under the scanning electron microscope (SEM).The terminal portion of the glands was composed of glandular cells and myoepithelial cells, the latter were starfishlike features and extended thin cytoplasmic processes which covered the small area of the terminal portion. The arterioles and venules could be clearly distinguished by their adventitial aspects and innervation pattern. Arterioles were occasionally connected to small arterioles with a characteristic structure, which seemed to play a role in the regulation of peripheral blood supply.     

Histochemical and immunocytochemical study of nitrergic innervation in human nasal mucosa.

Nitric oxide (NO) is a free radical gas that has been found to be produced in neuronal cells by the action of the enzyme brain nitric oxide synthase (bNOS). The aim of this study was to identify NO-containing nerve structures in the human nasal mucosa by localizing bNOS and to find out whether NO production is attached to the parasympathetic system. For this purpose, immunocytochemistry with antibodies to bNOS and neurofilament was performed. Additionally, nicotinamide-adenine dinucleotide phosphate diaphorase (NADPH-d), an enzyme that correlates with the localization of NO synthase, and acetylcholinesterase were visualized in a histochemical double staining technique on frozen sections. The NADPH-d and bNOS reactions were found in axons of nerve bundles and in subepithelial, glandular, and vascular nerve fibers. Arteries showed a distinctly developed nitric innervation, whereas no activity was found in nerve fibers supplying veins. A high coexistence of NADPH-d in parasympathetic nerves could be detected. These findings suggest that NO takes part in the nerve control functions of the human nasal mucosa.     

Scanning electron microscopy of the human nasal mucosa.

Nasal biopsies are taken from normals and from patients suffering from perennial rhinitis, nasal polyps, hay fever or atrophic rhinitis. The biopsies from the inferior nasal turbinate are studied in a scanning electron microscope. In conclusion, allergic reactions have only a slight, direct influence on the ultrastructure of the mucous membrane. Contrary to this, the surface of the nasal mucosa is characteristically altered in atrophic rhinitis. By chance it was observed how flagellated bacteria invades the mucous membrane by fastening to the epithelial cells, which consequently are expelled.     

Experimental studies on carcinogenesis in the nasal mucosa

Of 24 Syrian golden hamsters exposed to wood dust in a concentration in the air of 30 mg/m3 for 6 h per day, 5 days a week, for a period of 40 weeks, one animal got dysplasia and one a malignant tumour in the nasal mucosa. In a group of 24 animals given 3 mg of diethylnitrosamine subcutaneously once a week for 12 weeks, a high frequency of benign and malignant tumours (mainly adenocarcinoma) of the nasal mucosa was found, but a group of similar size exposed to both wood dust and diethylnitrosamine did not show a higher frequency of nasal tumours than those given this latter substance alone.     

Autonomic innervation of the vessels of the nasal mucosa: current concepts

The nasal cycle enables the conditioning of air breathed in. It depends on the vascular vegetative innervation. Whilst its central diencephalic origin is probable, its mechanics remain mysterious. The involvement at the loco-regional level of short circuits ensuring the anatomical links between the vegetative, sensitive and cellular systems of the nasal mucosa is the basis of a new approach to chronic rhinological pathologies and certain facial algias.     

Electron microscopic study of intercellular junction in nasal mucosa of nasal allergy by lectin histochemistry

To explain of the mechanism of the enhanced nasal epithelial permeability to HRP in patients with nasal allergy, the inferior turbinate mucosa was removed from 6 normal adults and 7 adults with nasal allergy. Difference of the fine structure of the intercellular junction was compared between normal mucosa and mucosa of nasal allergy by electron microscope. Staining pattern of four kinds of HRP-conjugated lectin (HRP-WGA, PNA, UEA-I and RCA-I) was also studied by electron microscope. There was no significant difference in the intercellular space of the mucosa between the normal mucosa and mucosa of nasal allergy. In the epithelial cell membrane, pattern of HRP-lectin staining was almost similar in both groups. In normal nasal epithelium, the intercellular junction consisted of junctional complex; adherent junction, desmosome and gap junction. The intercellular space was approximately 150-250 A in width. The tight junction was located beneath the luminal surface of the epithelium, and belt-like continuation connecting the adjacent cells. It was concluded that enhanced permeability to HRP in nasal allergy was not morphologic changes of the intercellular junction and component and distribution of the glycoconjugates in epithelial cellular membrane, but this may be based on functional changes.     

Morphological differences in innervation between mucous glands and serous glands: a quantitative histological study using the sublingual glands of elderly humans

Conclusion: In the sublingual gland, the serous lobule usually carried a higher density of NSE-positive nerve elements than the mucous lobule, whereas the mucous acinus in the mucous lobule was larger than the serous acinus in the serous lobule. Objectives: To demonstrate quantitative differences in nerve elements between the mucous and serous lobules of sublingual glands. Methods: This study investigated using specimens from 14 donated cadavers (mean age = 78 years). Since immunohistochemistry for neuron-specific enolase (NSE) stains all nerves in addition to other mesenchymal cells possibly of nerve origin, the present quantitative evaluation was based on NSE-positive areas per visual field under a ×20 objective lens (0.6 × 0.45 mm when printed). Results: In mucous lobules, the areas occupied by NSE-positive nerve elements ranged from 5798–16,541 μm² (mean ± SD = 9280 ± 2584 μm²). In contrast, the corresponding areas in serous lobules ranged from 7853–23,540 μm² (mean ± SD = 13,520 ± 4351 μm²). The difference in NSE-positive areas was statistically significant (p = 0.0022). However, the mucous acinus in the mucous lobule was 2-times larger than the serous acinus in the serous lobule (2474 ± 1477 μm² vs 1119 ± 632 μm²).