Use of the "partition" test in the behavioral and pharmacological experiments

Application of partition test measuring the behavioural activity of animals near the transparent perforated partition (dividing the experimental cage onto two halves) as a reaction to the partner in the neighbouring compartment of common cage, is considered. Behavioural reaction as a response to other individual differs in dependence on psychological and physiological states, social experience, strains of the animals and kinds of partner. Partition test may be productive in experiments studying mechanisms of sociability, anxiety, aggressive and sexual motivations, olfaction, as well as for screening of psychotropic drugs.     

Directed and spontaneous disulfide bond closure using hydrogen peroxide in the synthesis of endothelins-1 and -3]

The linear precursors of endothelin 1 and endothelin 3, natural vasoactive peptides, were obtained by using the Boc- and Fmoc-schemes of solid phase peptide synthesis. The methods of directed and spontaneous formation of two disulfide bonds in the molecules of these precursors were compared and shown to give comparable results. The conditions were found that provided the selective S-S-ring closure in the methionine-containing endothelin 1 by means of hydrogen peroxide without the undesired conversion of the Met residue into the corresponding sulfoxide.     

The ligand-dependent phosphorylation of epidermal growth factor receptors and the production of a secreted form of the receptor by cell strains of A-431 epidermoid carcinoma

Primary reactions on the addition of the epidermal growth factor (EGF) were investigated for the strains of A-431 cells, resistant to the antiproliferative effect of EGF. In spite of differences of EGF reception in the obtained strains, the EGF receptors in membrane preparations of these strains maintain the phosphorylating ability after addition of EGF. The rate of internalization of 125I-EGF in normal and resistant cells is the same. The production of a secreted fragment of the EGF receptor in resistant cells is lower than in normal ones. Questions of regulation of production of the normal receptor and of its shortened secreted fragment are discussed.     

Effect of prolonged interaction of mice with aggressive and submissive types of behavior on the concentration of serotonin, 5-hydroxyindoleacetic acid and noradrenalin in the brain

As a result of repeated experience of victories and defeats in mice of C57BL/6 line, submissive and aggressive types of behaviour were elaborated, the stabilization of which was accompanied by a change in serotonin and noradrenaline content in various parts of the brain, at least of two kinds. Nonspecific unindirected changes in transmitter' levels found in both groups of animals in comparison with the control, are apparently due to the experience of zoosocial contracts. Changes were also noted connected with specificity of the observed behaviour.     

The neurochemical control of aggression and submission]

Neurochemical mechanisms of agonistic behaviour in different models of aggression are discussed. The effects of aggression and submission experience in 10 mice intermale confrontations under conditions of sensory contact on the levels of brain neurotransmitters and their metabolites were investigated in 7 brain areas. The values obtained in aggressive and control, or submissive and control, animals were compared. In this comparison neurochemical alterations specific for aggressive or submissive behaviours, or nonspecific became apparent. The long experience of victories leads to activation of dopaminergic system through DA catabolism which leads to DOPAC formation. The long experience of defeats increases the 5HT metabolism and decreases NA level in some brain areas. The dopaminergic system of Nucleus accumbens and midbrain are nonspecifically activated in both aggressive and submissive animals. The investigation of values obtained in animals with conversion of behavioural type (after defeat of previously aggressive animals and/or display of aggressive reaction by previously submissive mice) allowed to find many significant differences between aggressive, submissive and "converted" males; in particular the amygdala is the site of opposite changes in 5HT system during inversion of aggressive or submissive behaviours. The above data evidence for the specific role of transmitter systems and brain structures in maintaining or inversion of different types of agonistic behaviour.     

Dopamine receptor genetic polymorphisms and body composition in undernourished pastoralists: An exploration of nutrition indices among nomadic and recently settled Ariaal men of northern Kenya

Background  

Minor alleles of the human dopamine receptor polymorphisms, DRD2/TaqI A and DRD4/48 bp, are related to decreased functioning and/or numbers of their respective receptors and have been shown to be correlated with body mass, height and food craving. In addition, the 7R minor allele of the DRD4 gene is at a higher frequency in nomadic compared to sedentary populations. Here we examine polymorphisms in the DRD2 and DRD4 genes with respect to body mass index (BMI) and height among men in two populations of Ariaal pastoralists, one recently settled (n = 87) and the other still nomadic (n = 65). The Ariaal live in northern Kenya, are chronically undernourished and are divided socially among age-sets.     

Linking microarray reporters with protein functions

Background  

The analysis of microarray experiments requires accurate and up-to-date functional annotation of the microarray reporters to optimize the interpretation of the biological processes involved. Pathway visualization tools are used to connect gene expression data with existing biological pathways by using specific database identifiers that link reporters with elements in the pathways.