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Background and Aim Methods and Materials

More than 75% of waste is toxic to the environment and humans. The aim of the study was to invistigate the toxic effect of ecotoxicants on the rudiments of the teeth of laboratory animals. The experiment was carried out on 30 white outbred rats weighing 180–250. All animals were divided into 2 groups: control (Group 1) and experimental (Group 2). During the experiment, all animals of the experimental groups were subjected to inhalation exposure to gasoline and formaldehyde vapors. Animals of the control group were supplied with normal air around the clock. The jaws of rats were decalcified for 30 days in a 10% formic acid solution in a 10% buffered formalin solution. After dehydration of the material in a battery of alcohols of increasing concentration (ethanol - concentration from 70% to 100% absolute) was poured into paraffin according to the generally accepted method. Using a rotary microtome brand LEICA RM 2145 (LEICA, Germany), histological sections 5–8 µm thick were made. The sections were stained with hematoxylin and eosin and picrofuchsin according to the Van Gieson method. Stained sections were examined and photographed using an AXIO IMAGER-Z1 light microscope (CARL ZEISS, Germany). In the control group of rats, a morphological picture of normal tooth histogenesis was observed at a late stage of development. In the structure of the tooth germs of rat pups of the 2nd group, a violation of the processes of histogenesis of most tooth germs and a change in the structure of the periodontal tissues were found. In the epithelium of the gingival mucosa, signs of dystrophic changes were determined, up to cell destruction; in the connective tissue plate of the gingival mucosa, in the periodontium and in the zone of formation of the alveolar bone, signs of inflammatory phenomena were determined in the form of cell infiltrations and circulatory disorders in the form of expansion of the lumens and blood filling of the vessels. In the area of the tooth germs, destructive changes in odontoblasts and enameloblasts were manifested, which was probably one of the reasons for the disruption of the processes of dentinogenesis and enamel formation, expressed in the heterogeneity of the formation of dentin and enamel layers. This confirms the toxic effect of ecotoxicants on the rudiments of the teeth of laboratory animals.

Блуждающий нерв является основным компонентом вегетативной нервной системы. Поливагальная теория рассматривает этот нерв как две структурно и функционально раздельные ветви – вентральную и дорсальную. Дорсальная ветвь существует у большинства позвоночных. Она связана с первичными стратегиями выживания в условиях сильного стресса, заставляя «притворяться мертвым, чтобы выжить». Вентральная ветвь характерна для млекопитающих и оказывает тормозящее влияние на симпатические пути к сердцу, тем самым способствуя спокойному и просоциальному поведению. Эта ветвь обеспечивает функционирование пищевода, бронхов, гортани и глотки. Мы изучали функциональное состояние вентральной ветви, учитывая, что именно она иннервирует мышцу, поднимающую нёбную занавеску и мышцы нёбного язычка. В качестве рабочей гипотезы предположили, что дисфункциональное состояние вышеперечисленных мышц встречается при функциональной дезадаптации вентральной ветви блуждающего нерва и регуляторных рефлекторных механизмах нервной системы, то есть при неврологической дезорганизации. У пятой части обследованных была выявлена неврологическая дезорганизация. Среди представителей этой группы дисфункциональное состояние нёбного язычка и нёбной занавески встречалось значительно чаще, чем при нормальной неврологической организации. Поэтому выявление наклона нёбного язычка, одностороннего провисания нёбной занавески в покое и при нагрузке рекомендуем использовать как достоверный визуальный индикатор диагностики неврологической дезорганизации. При нормальной неврологической организации самым чувствительным индикатором диагностики функциональной дезадаптации вентральной ветви блуждающего нерва является одностороннее провисание нёбной занавески при произнесении звука «а-а-а». Полученные результаты рекомендуем использовать для диагностики неврологической дезорганизации и функциональной дезадаптации вентральной ветви блуждающего нерва. The vagus nerve is the main component of the autonomic nervous system. According to polyvagal theory, this nerve is considered as two structurally and functionally separate branches, ventral and dorsal. The dorsal branch is found in most vertebrates. It is associated with primary survival strategies in conditions of severe stress, forcing to «play dead in order to survive». The ventral branch is characteristic of mammals and has an inhibitory effect on the sympathetic pathways to the heart and thus promotes calm and prosocial behavior. This branch ensures the functioning of the esophagus, bronchi, larynx and pharynx. We studied the functional state of the ventral branch, considering that it is the one innervating the soft palate muscle and the muscles of the uvula. As a working hypothesis, we assumed that the dysfunctional state of the above muscles is found in functional disadaptation of the ventral branch of the vagus nerve and in the regulatory reflex mechanisms of the nervous system, i.e. in «neurological disorganization». Neurological disorganization was detected in a fifth of those examined. In this group, dysfunctional condition of the uvula and the soft palate was significantly more common than in normal neurological organization. Therefore, we recommend to use the detection of a tilt of the uvula and unilateral sagging of the soft palate at rest and during exercise as a reliable visual indicator for the diagnosis of neurological disorganization. In conditions of normal neurological organization, the most sensitive diagnostic indicator of functional disadaptation of the ventral branch of the vagus nerve is unilateral sagging of the soft palate when makingg the sound «a-a-a». We recommend to use the results obtained to diagnose neurological disorganization and functional disadaptation of the ventral branch of the vagus nerve.