ULTRASTRUCTURAL ORGANIZATION OF THE RETINA LAYERS OF THE RAT IN NORM

Abstract

The use of experimental animals with the aim of studying the dynamics of morphological changes requires deep knowledge of the initial indicators of the structure of the studied object in norm. In scientifi c medical literature, great importance belonges to the study of the retina in norm and the processes of changes in its structure under the infl uence of various nosologies. Considering the complexity of the retina structure and its role in the receiving information from the surrounding environment, it is important to understand the peculiarities of its layered organization in order to create a morphological basis for further comparing the experimental material and comparing it with the initial indicators of the norm with the results obtained at diff erent periods of the experimentally reproduced pathology. The aim of the study was to fi nd out the peculiarities of the layered structure of the cellular elements of the retina on the ultrastructural level in norm. Material and methods. The research material was 10 sexually mature, purebred male rats, weighing 160 g, aged 4.5 months. Before taking the material of the experimental area, the animal was removed from the experiment with the help of diethyl ether. Rat eyeballs were used as material for ultrastructural research. Ultrastructural samples were prepared according to the generally accepted method. As a result of our study of the retina of an intact group of animals, its layers preserved a clear stratifi cation architecture. The layer of the pigment epithelium was localized on Bruch’s membrane, choroidal vessels contained single erythrocytes and blood plasma. The nuclei of the pigment epithelium were preserved, the basal folds of the plasmolemma were clearly contoured. Small phagosomes were located in the cytoplasm of the pigment epithelium in one or two rows. The apical microvilli of the pigment epithelium were preserved, the interphotoreceptor space was hermetic. The membrane discs of the outer segments of the rods were clearly contoured. The cytoplasmic isthmus between the outer and inner segments of photoreceptors was intact. The outer boundary membrane was intensively osmophilic, preserved. Photoreceptor nuclei in the outer nuclear layer, clearly contoured. The synaptic zone of the outer reticular layer contained synaptic membranes and synaptic vesicles. The nuclei of horizontal and bipolar cells, the nuclei of Mьller cells and the nuclei of amacrine cells were located in the inner nuclear layer. The lumens of the vessels of the inner reticular layer were not dilated, they contained single erythrocytes. Nuclei and perikaryons of ganglion cells were arranged in one or two rows. Cytoplasmic structures of large gangloinary cells were preserved.