[Dyspnea. I. Definition and pathophysiological problems]. / Dispnea. I. Definitsiia i patofiziologichni problemi.

An analytical review was made on the pathophysiological mechanisms suspected to be involved in dyspnea, accepting that the sensation of shortness of breathing, and the subjective signs (exertion, anxiety and fear) are essential for the diagnosis of this condition. Bearing in mind the anatomical relations in the central nervous system between the structures involved in the control and regulation of the respiration, and these involved in the emotions, a scheme was presented of the pathophysiological mechanisms, which determine the essential signs of the dyspnea. Three neuronal circuits were assumed for the explanation of the manifestations in dyspnea: subjective signs, symptoms of the thoraco-pulmonary and cardio-vascular systems, and these of the voluntary muscular system that accompanied dyspnea.

[Dyspnea. II. Clinical and treatment problems]. / Dispnea. II. Kliniko-terapevtichni problemi.

In a previous paper (Balanova, Surcheva and Ichev, 2001) we have proposed a scheme about pathophysiological mechanisms involved in dyspnea. Some of the clinical problems in dyspnea were discussed in this paper on the base of that scheme, as well as clinical observations on the patients with dyspnea. Two groups of symptoms were considered--subjective and objective, and their significance for the diagnosis of the dyspnea and of the disease that provokes dyspnea were evaluated. A critical analysis of the different forms of dyspnea has been made, and suggestions about the treatment of the subjective symptoms in dyspnea were proposed.

Changes in the neuronal plasma membrane during synaptogenesis.

During synaptogenesis the plasma membrane of neurons undergoes considerable changes and large portions of it develop to synaptic membranes. This transformation is brought about by biochemical and morphological changes. The aim of the present investigation was to study by morphological methods the in vivo changes of some basic components of the neuronal membranes during the early postnatal period, when active synaptogenesis occurs. The cerebral cortex of Wistar rats was used for preparation of either growth cones (up to postnatal day 10) or synaptosomes (postnatal days 14-30). Our studies were focused on the changes occurring in integral membrane proteins and cholesterol domains, and in certain carbohydrate residues and anionic sites. In the first days after birth relatively few intramembranous particles are found in the plasma membranes of growth cones, few and small cholesterol domains, scarce lectin-binding and anionic sites. During the following days there is a clear tendency for increase of the number of all of the studied structures until the appearance of typical synaptic membranes. Throughout the studied developmental period the protein and the cholesterol molecules were found to occupy distinct membrane domains. The structure of the developing neuronal membrane, poor on proteins and cholesterol, and its maturation to the fully functional synaptic membrane is discussed.

Light and electron microscopic demonstration of cholesterol distribution in membrane structures of the rat auditory cortex.

As part of our investigations on the changes in the cortex of different stages of ontogeny, the aim of this study was to analyse the cholesterol distribution in the auditory cortex of adult rats. The light microscopic Schultz reaction as well as electron microscopic thin sections and freeze-etching combined with a cholesterol specific marker were applied to cholesterol demonstration. High and low cholesterol areas were found in the plasma membrane and membranes of some organelles. A low cholesterol content was observed in the membranes of the Golgi apparatus, mitochondria and junctional contacts. A very low cholesterol content was found in the pre- and postsynaptic membranes. High cholesterol contents were present in the neuronal and glial non-junctional plasma membranes. The cholesterol distribution in the membranes of the endoplasmic reticulum and nuclear envelope appeared to be different.

A freeze-etch study of the central myelin.

The intramembranous organization of the interparanodal myelin lamellae in CNS was investigated by means of the freeze-etching technique. The density of the IMPs is about equal on both P- and E-fracture faces of every myelin sheath but varies between the myelin sheaths. The morphology of the myelin tight junctions was also described. The nature of the IMPs and the functional significance of their mode of distribution were discussed.

[The morphology of the glial cells in the inferior olivary complex of ground squirrels (Citellus citellus L.). I. Oligodendrocytes]. / Morfologiia na glialnite kletki v dolniia olivaren kompleks u laluger (Citellus citellus L.). I. Oligodendrotsiti.

The morphological characteristics of oligodendrocytes in the lower olivary complex of ground squirrels at various ages were studied by light and electron microscopes. On the basis of an analysis on thick sections, stained with toluidine blue, it was established that nuclei of these cells were smaller and darker in comparison with those of astrocytes. The mean oligodendrocytes, located in perineuronal, perifascicular, perineuronal-perifascicular, interfascicular, perivascular position or freely situated, predominated in the neuropile of the lower olivary complex. Changes in their ultrastructure were investigated during advancement of age and during the process of aging. An increase in the number of heterogeneous dense bodies were found as well as the presence of lipid-pigmented granules with crystal-like brightening. The connection of oligodendrocyte growth with myelin sheath of axons.

[The ultrastructure of the inferior olivary complex in ground squirrels (Citellus citellus L.). The neuropil. Age-related changes in the axons]. / Ultrastruktura na dolniia olivaren kompleks u laluger (Citellus citellus L.). Nevropil. Vuzrastovi promeni v aksonite.

The morphological characteristics of axon terminals among a neuropil in the lower olivary complex of ground squirrels at various ages were studied by an electron microscope. The presynaptic part of the chemical synapses in the glomerular or outside glomerular position among the neuropil pf this nuclear complex were axon terminals and terminals "en passant". These axon elements participate in the formation of crash-like synapses with somatic, dendrite prickles, but also with dendrite adjuncts in the formation of complex synaptic connections. A considerable part of myelin axons and axon terminal were changed in old ground squirrels during all seasons. There were two varieties: 1. axon elements with preserved sizes and dense bodies, myelin-like figures, a large number of mitochondria and glycogen granules were found among normal organoids. 2. myelin and amyelin "spheroids" with various sizes and inner structure. The changes axon elements of the neuropil in the inferior olivary complex of ground squirrels at various ages during all seasons are physiological probably connected with the process of aging.

Anionic sites in the myelin sheath as shown by cationized ferritin.

The distribution of anionic sites in the myelin sheath of sciatic nerves of rabbits was studied using cationized ferritin. Ferritin molecules were observed on the cytoplasmic sides of the myelin lamellae stratified in paranodes and Schmidt-Lanterman clefts. In the compact myelin, ferritin molecules have not been found in the tissue sections. They have been observed on membranes of the myelin fraction. The significance of the localization of negatively charged groups on the cytoplasmic side of membranes is discussed.

[Cytochemical localization of concanavalin A binding sites in the peripheral nerve axons of old rats]. / Tsitokhimichna lokalizatsiia na konkanavalin-A svurzvashtite mesta v aksonite na periferni nervi na stari plukhove.

Distribution of alpha-D-mannose and alpha-D-glucose residues of glycoconjugates in axons of sciatic nerves of 24-month old rats of Wistar strains was studied by concanavalin-A-ferritin conjugate. In some of axons there were cumulations of ferritin molecules in agglomerates of various size with polarization of the phenomenon at preserved integrity of myelin sheath. In other cases the concentration of a large number of lectin binding sites was established in the region of the degenerating part of myelin sheath, engrossed in the axon cylinder. The changes in the distribution of carbohydrate residues in the axoplasm of some of the fibers are discussed in connection with the occurring axonal atrophy in fibers of peripheral nerves of old rats.

Localization of concanavalin A--binding sites on neuroepithelial cells in early newt's neurula after treatment with noradrenalin.

The concanavalin A (Con A)--binding sites on the cell surface of newt's neural plate and groove in norm and following treatment with noradrenaline (NA) were examined ultrastructurally. The changes in the distribution of Con A--binding sites as well as structural changes of endocytic vacuoles in experimental conditions were described. The present results suggest that the differences in the Con A--binding were caused by receptor interaction of the plasma membrane glycoconjugates and the applied neurotransmitter.

[Changes in the actin distribution in the neurons of the cerebral cortex in newborn, adult and old rats]. / Promeni v razpredelenieto na aktina v nevronite na goliamomozuchnata kora na novorodeni, izrasnali i stari plukhove.

The distribution of actin in neurons of sensorimotor cortex of newborn, 3-month- and 12-old-month old rats was studied by an immunohistochemical method. There was a diffuse staining of perikarya [correction of perikaryocytes] in contrast to the mature 3-month-old rats in which immunopositive material was located mainly at the periphery of neuronal bodies. A diffuse immunostaining was established in some nerve cells of the elderly 12-month-old rats.

[Ultrastructural research on the sensorimotor cortex in adult rats. I. Intranuclear inclusions in the neurons and astrocytes]. / Ultrastrukturno izsledvane na senzorimotoronata kora vuv vuzrastni plukhove. I. Vutreiadreni vkliuchvaniia v nevronite i astrotsitite.

The morphological peculiarities of neurones and astrocytes in the sensorimotor cortex of mature (over 3 months) and elderly (over 24 months) rats were studied at electron microscopic level. Intranuclear inclusions are found in the nuclei of pyramidal neurones from the third and fifth layer. On the basis of their fine structure they could be grouped into the following types: 1. Filamentous bundles. 2. Filamentous crystalloids. 3. Granulofilamentous bodies. 4. Membrane-enclosed inclusions. 5. Combined intranuclear inclusions. Filamentous crystalloids are found in two varieties, composed of filaments with various diameter and way of arrangement. Membrane-enclosed bodies are formed as small vesicles or large vacuoles. Combinations from various types of inclusions in the nucleus of a neurone are discovered frequently. Only intranuclear inclusions of the type of membrane-enclosed bodies are observed in the nuclei of astrocytes. These bodies are found only in the nuclei of astrocytes of elderly animals. On the basis of the comparative analysis between ultrastructural characteristics and frequency of intranuclear inclusions in pyramidal neurones and astrocytes in sensorimotor cortex of mature and elderly rats their probable connection with age changes in the central nervous system is discussed.

[Free postsynaptic-like compactions in the inferior olivary complex of the suslik (Citellus citellus L.)]. / Svobodni postsinaptichnopodobni uplutneniia v dolniia olivaren kompleks na laluger (Citellus citellus L.).

The morphological peculiarities of the neuropil [correction of neuropapilea] in the inferior olivary complex of young and elderly ground squirrels were studied by and electron microscope during periods of hibernation and waking. In some of the distal and middle dendrites and dendritic spines [correction of prickles] in elderly ground squirrels there were plaques, composed of electron-dense material with structure similar to postsynaptic condensations, but without presynaptic specializations of chemical synapses. The free postsynaptic-like condensations are located usually in dendrites, which fit to the cellular bodies and sprouts of oligodendrocytes, myelin sheath of nerve fibers and more rarely to astrocytes or lamellae and in single cases to neuronal perikaryon. The significance of the free postsynaptic-like condensations and their connection with age changes in the central nervous system is discussed on the basis of the comparative analysis of the morphological characteristics of the neuropil [correction of neuropapilea] in young and elderly ground squirrels during various seasons.

A freeze-etch study of the central myelin.

The intramembranous organization of the interparanodal myelin lamellae in CNS was investigated by means of the freeze-etching technique. The density of the IMPs is about equal on both P- and E- fracture faces of every myelin sheath, but varies between the myelin sheaths. The morphology of the myelin tight junctions is also described. The nature of the IMPs and the functional significance of their mode of distribution are discussed.

Neuronal Na+, K+-ATPase in the peripheral nerve fibers.

ATPase activity was localized by means of Wachstein-Meisel's method in rat sciatic nerve fibers. Using controls with ouabain, the presence of alpha + (neuronal) Na+, K+-ATPase was examined. The enzyme occurs in the ATPase reaction of the myelin-forming membranes, axoplasm and Schwann cell cytoplasm. Its presence in the Schwann cell plasma membrane is only admittable. The ATPase activity of the compact myelin and axolemma was exclusively of alpha + type of Na+, K+-ATPase.

Cytochemical localization of ATPase in axon-myelin-Schwann cell complex type.

ATPase activity was studied in the structures of axon-myelin-Schwann cell complex of sciatic nerves of rabbits of pre-and postnatal development. Positive reaction was observed on the plasma membrane, mitochondria and endoplasmic reticulum of Schwann cells, on the intraperiod lines of the compact myelin, in the split myelin lamellae in the paranodal regions and Schmidt-Lanterman clefts, in segment of outermost lamellae split off from the interparanodal myelin, in the mesaxons, in the loose myelin lamellae in the earlier stages of myelinization, on the axolemma (periaxonal space) and axoplasm. The ATPase activity on the Schwannian plasmalemma, axolemma and myelin sheath surface was found to be heterogeneously distributed. An accumulated of reaction deposits at the origin of the outer mesaxon, at the axoglial contacts as well as at the terminal part of the myelin sheath was respectively observed. Alterations of the enzyme activity distribution in axon-myelin-Schwann cell complex during rabbit's development were found to be associated with the growing myelin sheath and its node-paranode. Using controls with ouabain an attempt was made the possibilities of Wachstein and Meisel's method to be shown and the place of alpha+ form of Na+, K+-ATPase in the axon-myelin-Schwann cell Complex to be establish.

Visualization of anionic sites using polyethyleneimine-metal complexes.

17 Polyethyleneimine-metal complexes were synthesized and 3 of them were tested cytochemically for visualization of negative tissue charges. The demonstration of the anionic sites was carried out on rat cerebral cortex and on frog cutaneous pectoral muscle. As controls, neuraminidase digestion, methylation, and omission of osmium-postfixation were used. The osmiophilic properties of polyethyleneimine, polyethyleneimine salts, and polyethyleneimine-metal complexes were discussed.

[Changes in the distribution of negatively charged sites of the synaptosomal membrane in adult rats]. / Promeni v razpredelenieto na negativno zapredenite mesta po sinaptozomalnata membrana na vuzrastni plukhove.

Changes in the distribution of Anionic sites on the synaptosomal membrane of old rats were investigated by means of cationized ferritin. Synaptosomal fraction was isolated from the cerebral cortex of two groups of rats: a control group-rats aged 2 months and second group-rats aged 14 months. Some diminishing of density was established on anionic sites as well grouping in larger or smaller aggregates of the same sites on the membrane of some synaptosomes of old rats.

[Age changes in the distribution of VIP-positive neurons in the rat auditory cortex]. / Vuzrastovi promeni v razpredelenieto na VIP-pozitivnite nevroni v slukhovata kora na plukh.

Using the methods of immunocytochemistry, we made a study on VIP-ergic neurons in the auditory cortex of young and aged rats. Comparing the results we observed considerable diminution in the number of VIP-positive neurons of aged animals in all cortical layers.