Abstract:Hippocampus ensures the implementation of the memory mechanisms, behavioral reactions, including avoidance of stress, aversive effects etc. The study was performed on the material of 20 male Wistar rats weighing 220-250 g, 10 of which were intact control group and 10 were experimental group, in which chronic immobilization stress was simulated. We determined the relative number of neurons in multiple fields of view on the total area of the pyramidal and polymorphic layers of CA1 and CA3 regions (further recalculated per 10,000 µm), larger and smaller diameters of neuron's bodies, their perimeters and areas with diameters of nuclei and nucleoli, nuclear-cytoplasmic ratio. It is found that under chronic immobilization stress in areas CA1 and CA3 of the hippocampus the morphologically similar neuronal lesions, decrease in their number, and change in nucleocytoplasmic ratio are observed.

Исследовано церебропротекторное действие карбамилированного дарбэпоэтина и дарбэпоэтина альфа. Эксперименты проведены на крысах-самцах линии Вистар с использованием модели четырехсосудистой ишемии-реперфузии головного мозга. Установлено, что предварительное трехкратное внутрибрюшинное введение карбамилированного дарбэпоэтина (100 мкг/кг) с интервалом в 3 дня оказывает выраженный прекондиционирующий церебропротекторный эффект, что проявляется меньшим неврологическим дефицитом и большей активностью животных, получающих препарат перед моделированием четырехсосудистой ишемии, а также сохранностью нейрональных слоев гиппокампа и коры большого мозга при морфологическом исследовании.

Aim. To study the morphological features of lymph nodes in people aged 65-69 years and to analyze the results with data from other researchers. Materials and methods. The study was carried out on 30 lymph nodes obtained during autopsy of people aged 65-69 years. Lymph nodes were subjected to standard histological protocol; slides were stained with hematoxylin and eosin. An immunohistochemical study was performed to determine the expression of the markers Ki-67, p53, bcl-2 and Cyclin B1. Results. The thickening of the capsule and connective tissue trabecules were determined on the sections of the lymph nodes, the cleavage of trabecules by adipocytes. The zonal structure of the lymph node is smoothed. Lymphatic nodules in the cortex have unclear contours, they do not have germinal centers. The boundaries of the internodular zone and paracortex are not determined. The marginal sinus is unevenly expanded. In the medulla, medullary cords are replaced by white adipose tissue. The medullary sinuses are dilated, adipocytes are located in the lumen of some of them. Small arteries and arterioles with thickened walls and signs of hyalinosis occur. An immunohistochemical study of the proliferative activity of lymph node cells shows a significant decrease in the number of positively stained lymphocytes in both the cortex and medulla by the expression of the Ki-67 marker. In a study of the expression of Cyclin B1 and p53 receptors, the reaction is negative in both cases, while a reaction with antibodies to bcl-2 revealed weak cytoplasmic staining of lymphocytes of the cortex and medulla. Conclusion. Own and literature data shows that with age, unidirectional degenerative and dystrophic changes occur in the lymph nodes of humans, rats and mice. This results in increase in the proportion of connective and adipose tissue and a decrease in lymphoid tissue in the lymph nodes. These changes can be considered morphological signs of inhibition of lymphocytopoiesis, humoral and cellular immunity in the lymph nodes.

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