The literature overview describes modern standpoints about the role of vessel endothelium in regulating cerebral hemodynamics - from complete denial of this possibility to recognition of the leading role of endothelial mechanism in controlling vessel functions. The paper summarises results of authors’ researches and literature over the last fifty years into the endothelial (intimal) mechanism of blood circulation regulation. As reported, the adequate blood supply of brain results from interaction between several mechanisms. Researching these mechanisms will allow identify the role of endothelium in the single system of blood supply of brain.

Summary - The paper provides new published data and results of authors’ studies on physiology and pathology of hydrogen sulphide gas transmitter. The hydrogen sulphide is synthesised from cysteine by pyridoxal-5’-phosphate-dependent enzymes of cystathionine-ß-synthase or cystathionine-Y-lyase. It stimulates the ATP-dependent potassium channels in the vascular smooth muscle cells, neurons, cardiomyocytes, and ß-cells of pancreatic gland, thus being involved in regulation of vasomotor tone, reduction of cardiomyocytes, neurotransmission, and insulin secretion. The authors describe effects of hydrogen sulphide-inducing systems on the pathogenesis of arterial and lung hypertension, Alzheimer disease, and liver cirrhosis.

The authors consider vessel endothelium as active endocrine organ that synthesises substances known to be very important for controlling blood clotting, regulation of vasomor tone and arterial tension, filtration function of kidneys, contractive activity of heart, and metabolic support of brain. The paper provides data from literature and authors’ studies on endothelium dysfunction in patients with risk factors for cardiovascular diseases and in patients suffering from ischemic heart disease and arterial hypertension. As reported, given the risk factors, there is a decrease in nitric oxide production and increase in vasopressor endothelium-1 production. In case of ischemic heart disease the extent of endothelial dysfunction is aggravated and characterised by decreasing endothelium-dependent vasodilatation. The cerebral blood flow seems to be most protected: considerable changes in the average velocities of blood movement and peripheral vascular resistance indices are observed, given the grade III arterial hypertension.

The author presents an overview of literature and his own studies on the structure of temporal lobe as one of the most epileptogenic areas of brain. The epileptic lesions most often result from innate developmental disorders (dysgenesis) and acquired exogenous post-injury and inflammatory brain lesions. At functional and neurochemical levels, these disorders are characterised by prevailing inhibitory and insufficient inhibitory synaptic processes. The cerebral anoxia and ischemia associated with the epileptic seizure as well as experimentally simulated kainite hyperexcitability result in inverse differentiation and elimination of neurocytes via apoptosis, deficient inhibition, disordered synaptic arrangement, and gliosis. Epileptiform activity arises from plastic synapse modifications that appear to enhance efficiency of excitative transmission and disturb the balance of inhibitory and excitative mediatory systems.

The authors provide an overview of modern studies and developments in the field of biocompatible implantable materials designed for treating degenerative and post-injury pathologies of central nervous system. As reported, the critical analysis of materials and their components derived from natural and synthetic polymers allows concluding that their application as matrix implants can make it possible to recover the integrity of injured brain, adjust supportive and trophic functions, and induce reparative processes due to inner and implantable cell sources. The up-to-date state of biomedical material sciences and tissue engineering for the needs of neurotransplantology is characterised as analysis of capability of materials to imitate the structure and functions of natural extracellular matrix, inducing neurogenesis and recovering conductive functions of the nervous system, and capabilities of materials to be exposed to controlled biodegradation with subsequent substitution with tissue structures.

New knowledge about stem cells that make it possible to in a new light interpret the functioning of nervous tissue in health and disease has been obtained during the last fifteen years. As reported, the proliferating stem cells in a definitive brain under certain conditions can be involved in reparative regeneration by substituting dead elements. The authors identify genome mechanisms of regulating proliferation and differentiation of stem cells and point out their role in producing malignant tumours and tropism of these cells to the tumours. These data open new opportunities for studying brain functioning and development. The neutral stem cells can be used to develop new technologies, treat neurogenerative and oncological diseases of brain.

The author presents a concise overview of literature and her own studies on the neurochemical and typological heterogeneity of the retinal neurons and substantiates the important role of plurichemical principle of neurotransmission in arranging module-like structure of retina, in the mechanisms of neuroplasticity and adaptation. As reported, the nitric oxide is responsible for maintaining these processes due to its central integrative function.

The discussions between neuronists and reticularists have been characterised by complete mutual flat rejection of the opposite theory. The neuron doctrine relies on the discovery of synapses via electronic microscope but this discovery in principle does not deny transneuronal syncytium. Today, there are factors that are inconsistent with the neuron doctrine. These are: presence of highly porous membrane contacts with intracellular pores, inconsistence with cell theory, etc. These data require the neuron doctrine to be supplemented and modernised. The key question, whether there are cytoplasmatic syncytial ties between neurons, remains unanswered. These ties between giant cells and fibres in molluscs, crustaceans, polychaetes, and other invertebrates have been proved a long time ago. The paper first summarises data about syncytial ties of vertebrates’ neurons in the cortex of cerebrum, hippocampus and autonomous nervous system of vertebrates. As reported, it results from the deficit in glial neuron cover, on gap or tight junctions. The authors describe syncytial pores and wide perforations of conjugated neuronal membranes and their fusion in rats’ embryos and indicate a method of targeted experimental fusion of neurons.

The paper provides an overview of the results of morphofunctional studies of the olfactory system organs of sea and migratory fish with regard to their ecology and systematic position, summarises up-to-date notions about flagellate and microvillar types of the olfactory receptors and discusses secretory system of the olfactory epithelium that includes in several species specialised alveolar and tubular glands like Bowman>s glands, its role in primary processes of the olfactory reception, and protective response in case of toxicant exposure. Analysing materials on the olfactory organ evolution allows to identify general tendency to reduce the total surface and rugosity of olfactory rosettes of cartilaginous and bony fishes, for example, progressive trend of the evolution - homologon oligomerisation. As reported, the levels of hyper-, macro-, medium-, and microsmatia depend on ecological features being observed in various fish species

The paper provides main theses of fundamental neurohistochemical studies performed by P.A. Motavkin and his disciples dedicated to the study of enzymes and differentiated mediatory organisation of brain. Results of researches carried out for the last years have been successfully introduced in practice of forensic medicine, thanatology and toxicology. It will be very promising to proceed with this scientific field.

The paper considers issues of pre- and post-natal ontogenesis of cardiovascular system innervation and nitroxidesynthase contents in heart ganglions in health and disease. The paper bases upon analysis of 12 series of human embryos, study of cardiovascular system in 23 foetuses and materials of 124 early autopsies of people of various age in health, in case of sudden cardiac death and a number of cardiological diseases studied with neurohistological, histochemical and ultrastructural methods, and immunohistochemical methods for the nitric oxide synthase contents. The author presents results of parallel time-frequency spectral analysis of heart rhythm variability in health and ischemic disease in 43 patients of various ages.

The paper presents overview of literature dedicated to the mechanisms of programmed cell death (apoptosis) and considers morphology of apoptosis and necrosis, factors known to activate and suppress these processes, and role of apoptosis and necrosis in inducing inflammatory responses and regeneration.

The data about histological organization and gonads cell composition of hydrobionts were receive, which complete information about their reproductive biology and allow give concrete expression to spawning period. Influence of some important ecological factors on the reproduction of these hydrobionts was analyses. They may be use for cognition peculiarities biology of reproduction present invertebrates and for development of coastal fishery in connection of rational fishery these organisms and their reproduction.

The paper summarises results of long-term laboratory and field studies on the effects of environmental pollution on the gametogenesis, breeding and reproductive cycles of sea urchins and bivalve molluscs. The disordered gametogenesis can serve as a sensitive indicator of marine environment pollution. The authors estimate informativity of various indicators of reproductive function of these species and cite data from the studies about spawning period of Strongylocentrotus intermedius from the north-western sea areas of the Sea of Japan with various anthropogenic stresses. The authors focus attention on a shift in the spawning period from autumn to early summer in sea urchin habitats known to be high-polluted, and discuss probable mechanisms of this phenomenon.

The paper provides an overview of scientific achievements of the staff, post-graduate and PhD students from the VSMU Department of Histology and focuses upon neuroparacrine mechanism and role of endothelium in regulating cerebral circulation. The author fully considers structural and functional ontogenetic features of the intraspinal organ and identifies its place among ependymal neoplasms of the central nervous system. The paper includes results of researches into the mediatory specialisation of brainstem neurons and prospects of supraneural system mapping and makes reference to the works dedicated to the regulatory mechanisms of marine invertebrates reproduction performed together with the academician institute personnel. As reported, 130 PhD and doctoral dissertations have been defended, 30 books have been written, and about 300 papers have been published.