The central nucleus of the amygdala: cytoarchitechtonics, neuronal organization, and histophysiology

Neurologists' attention is attracted by amygdala's central nucleus which takes part in formation of stress response and adaptive behaviour in animals. The data on cytoarchitectonics, neuronal organization and histophysiology of this important centre are based on current knowledge of its subnuclear organization.     

Structural organization of amygdaloid brain complex of the rat

Amygdala belong to the system of basal nuclei of telencephalon. Amygdala are a complicated structure based on both principles of grey matter organization: nuclear and screen-type, on its territory. Authors investigate into the structure of Amygdala using theory of Zavarzin A. As the result of this study, a classification of components of Amygdala into nuclei, paleocortical and intermediate formations, has been developed.     

Mitotic index of meristematic cells and root growth of Pisum sativum is affected by inositol cycle modulators

Relationships between cell division and inositol cycle modulation caused by different effectors in roots of Pisum sativum were studied. Stimulation of the inositol cycle by myoinositol increased the mitotic index of meristematic cells and root length, while the inhibition of the cycle with Li+ and a heavy metal Gd3+ considerably decreased mitotic activity and growth. Exposure of roots to 10 mM CaCl2 and 15 mM myoinositol resulted in the accumulation of chromosome aberrations. Changes in the activity of inositol cycle are assumed to be involved in the root growth control.     

Cell surface peroxidase--generator of superoxide anion in wheat root cells under wound stress

Development of wound stress in excised wheat roots is known to be accompanied with an increase in reactive oxygen species (ROS) production, fall of membrane potential, release of K+ from cells, alkalization of extracellular solution, changes in respiration and metabolism of structural lipids. Dynamics of superoxide release correlates with changes in other physiological parameters, indicating the cross-reaction of these processes. Activity of peroxidase in extracellular solution after a 1 h incubation and removal of roots was shown to be stimulated by the range of organic acids, detergents, metals, and to be inhibited by cyanide. Superoxide production was sensitive to the addition of Mn2+ and H2O2. Increase in superoxide production correlates with the enhancement of peroxidase activity at the application of organic acids and detergents. The results obtained indicate that cell surface peroxidase is one of the main generators of superoxide in wounded wheat root cells. Different ways of stimulation of the ROS producing activity in root cells is supposed. By controlling superoxide and hydrogen peroxide formation, the cell surface peroxidase can control the adaptation processes in stressed plant cells.     

Cytologic characteristics of "dark" and "light" cells in the brain amygdaloid complex

This paper reports data on cytological peculiarities of neurons of two main zones of sexual dimorphism in brain amygdala (dorsomedial nucleus and anterior cortical nucleus). The main attention was paid to some characteristics of "dark" and "pale" cells found in the amygdaloid complex for the first time. It is supposed that the dark and pale cells are targets for gonadal steroids, whose cyclic changes in concentration in the blood difined their functional states. Though the ultrastructure of dark and pale cells of the amygdaloid complex is similar to that of neurosecretory cells of hypothalamus, there are necessary electron microscopic and cytochemical evidences.     

Superoxide Production and the Activity of Extracellular Peroxidase in Plant Tissues under Stress Conditions

The production of reactive oxygen species on the plant-cell surface is considered. Along with the plasmalemmal redox systems, cell-wall peroxidase is involved in the production of superoxide and hydrogen peroxide. Under stress conditions, some soluble peroxidase isoforms are easily secreted into the apoplast. Various membranotropic compounds, salicylic acid in particular, can also induce this process. Mobile peroxidase forms are supposed to induce the plant defense response.