Vol 135, No 1 (2009)

The ultrastructure of hippocampal CA1 area was investigated in rats 14 days after status epilepticus was induced by kainic acid. The structural alterations were found in 40% of the cells, predominantly in interneurons, which demonstrated both reversible changes (mitochondria with a dilated space between cristae and electron-dense matrix or mitochondria with few short cristae and moderately widened rough endoplasmic reticulum [RER] cisterns with few ribosomes) and more significant alterations (swollen mitochondria containing single dilapidated cristae, including those with damaged mitochondraial membranes, pathologically dilated RER profiles and focal or peripheral chromatolysis. In the areas subjected to chromatolysis, the membrane-like inclusions and vacuoles were sometimes observed. Besides, large osmiophilic irregular structures, surrounded by astrocyte processes rich in glycogen granules and gliofibrills, were rarely found in the neuropil. The synaptic architectonics was also changed. Asymmetrical synapses on small dendrites and spines containing osmiophilic postsynaptic zone were frequently observed. Their synaptic endings contained numerous synaptic vesicles and large vesicles with a central dense core. Some part of presynaptic endings showed clear signs of a classical dark-type degeneration. As in all the altered neurons the nucleus remained intact, we suggest that after status epilepticus the majority of the cells underwent the necrotic-type pathological changes.

Epidural space development was studied in 51 embryos and early fetuses aged 4-13 weeks sectioned serially, using histological and embryological methods of plastic and graphic reconstruction. Three stages were determined in the development of the epidural space: I - primary epidural space (embryos of 16-31 mm crown-rump length [CRL]); II - reduction of the primary epidural space (embryos of 35-55 mm CRL); III - secondary s epidural pace (embryos of 60-70 mm CRL and fetuses of 80-90 mm CRL). Morphogenesis of the primary epidural space is determined by the forming influence of the spinal cord and its dura mater and that of the secondary one - by the walls of the spinal canal. In the correlation chain: the spinal cord - spinal cord dura mater - spinal canal, the latter two elements being under the inducing influence of the first one, determine the morphogenesis of the epidural space through the system of morphogenetic correlations. These correlations are manifested in the form of time-conjugated connection between the formation of the parts of spinal cord dura mater and the spinal canal causing the staged formation of the epidural space in ventrodorsal and craniocaudal directions. The same morphogenetic correlations also determine the stages in the development of the epidural space.

The distribution of SP-positive structures in the thymus and their connection with the antigen presenting cells (MHC-II-expressing) were studied under normal conditions and in male sex hormones deficiency (gonadectomy). Indirect immunohisto-chemical immunofuorescence method with the antibodies against Major Histocompatibility Complex class II proteins (MHC-II, antigen presenting cell marker) and against substance P (SP) was used. The population of antigen presenting cells (expressing MHC-II) and SP-positive structures of the thymus were found to form contacts. Gonadectomy resulted in the increased numbers of antigen presenting cells both in thymic medulla and cortex of thymus and in the decrease of SP-positive cell number in all the zones of thymic lobules. The results of this study demonstrate the existence of close cooperation between endocrine, neuropeptide and immunocompetent systems.

The objective of this study was to analyze the peculiarities of kidney growth and calyceal-pelvic system (CPS) development during the prenatal and early postnatal ontogenesis. The study included 166 kidneys of the fetuses of both sexes aged 13-40 weeks, 18 kidneys of the newborn infants and 98 kidneys of 58 children aged from birth to 7 years. 110 CPS casts were also prepared. It was found that the kidney growth had periods of acceleration (weeks 12-13, 27-28 and 39-40 of fetal development, neonatal period, breast-feeding age) and deceleration (23-26, 32-33 weeks, first childhood). The volume growth of kidney CPSs system in newborns and infants preceeded the growth of organ parenchyma.

In this study, 232 girls aged 16-20 years were examined using a program including the measurements of 29 anthropometric body parameters, determination of a somatotype, estimation of structural, metabolic and regulatory characteristics of the blood cells (lymphocytes and neutrophilic granulocytes) during the period between the examinations and under the condition of examination stress. The differences of morpho-functional characteristics of blood cells were detected between the representatives of extreme variants of physical development. In the girls with high body fat content, high activity of succinate dehydrogenase, low content of not readily oxidizable phospholipids in lymphocyte membrane at rest were detected together with low levels of class А and E immunoglobulins in blood serum. Under stress conditions, a significant reduction of the activities of energy metabolism enzymes and an increase of the hydrolase activities were found. In girls with poorly developed body fat component, the cells are characterized by component are characterized by greater inertness of the intracellulat enzymes at rest and their stability in stress.

This review discusses the new data on the neurobiological processes which are associated with addiction. Addictive drugs provoke stable alterations in the brain, which are responsible for the long-term behavioral disturbances. The mechanisms that determine their development, are very similar to those involved in the other forms of neural plasticity. This is indicative of the existence of some pathways in the brain by means of which it adapts to different influences. Thus, the main features of addiction, memory and learning are equivalent, however, at present it remains unknown, which cellular and molecular alterations provoke almost permanent adaptations associated with addiction, learning and memory. Functionally, more significant effect is provoked by the addictive drugs in the developing central nervous system of adolescents due to the high level of plasticity characteristic of the young organism.