Effect of a derivative of GABA, phenibut, on behavior and the activity of visual cortex neurons of the rabbit during elaboration of a defensive reflex and internal inhibition

In experiments on alert non-immobilized rabbits the effect of subcutaneous administration of the GABA-derivate--phenibut on behaviour, slow potentials and impulse activity of neurones of the visual cortex was studied during elaboration of a defensive reflex to light flashes and of conditioned inhibition. During the action of phenibut late negative-positive components of the evoked potentials to flashes, corresponding inhibitory pauses and postinhibitory activation gradually increased; then stable predominance of slow high-amplitude potential oscillations and corresponding neuronal group bursts appeared, separated by inhibitory pauses and in intersignal periods. Reinforcing stimulus, as before phenibut administration, lowered the amplitudes of slow potential oscillations and weakened inhibitory pauses in neuronal impulse activity. Dynamics of movements in response to the stimuli was of a phasic character. 3 hours after phenibut administration the discrimination of reinforced and inhibitory light flashes has distinctly improved. The obtained results confirm the initial concept of the significant role of the GABA-ergic inhibitory system in the process of elaboration of internal inhibition.     

Dynamic thermal mapping of rat brain during sensory stimulation and spreading depression

Using both techniques of thermovision and statistical analysis of thermal imaging, dynamics of temperature distribution over the dorsal surface of the brain were investigated through the intact skull during acute experiments on white rats. Both diffuse and regionally specific cerebral thermal reactions were observed during visual, acoustic, and somatosensory stimulation, together with multiple local thermal response, often following a specific pattern. These outline thermal effects differing from the compartment of the brain to another in degree, stability, and point of onset. Temperature waves developed together with spreading depression, produced in the cortex by injecting KC1. Once investigations had been performed this response could be divided into diffuse and spatially ordered components. The possible mechanisms of this thermal imaging of brain processes are discussed, together with how they are linked with changes in cerebral blood flow and neuronal metabolic thermal production.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Institute of Radio Engineering and Electronics, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 18, No. 1, pp. 26–35, January–February, 1986.     

Effect of regulators on bacterial autolysis

The aim of this work was to study the effect of autolysis regulators (the fraction of microbial teichoic acids) on the rate of autolysis and the activity of bacterial extracellular lytic enzymes. The regulators of autolysis isolated from 23 cultures belonging to 10 microbial species regulated the rate of autolysis in Bacillus, E. coli and Streptococcus lactis. The regulators either activated or inhibited autolysis depending on the substrate (of a bacterium to be subjected to autolysis). The quantitative dependence of the autolysis rate on the regulator concentration was specific for each pair 'regulator--substrate'. The regulatory properties of the fraction of teichoic acids varied depending on the age of a culture from which they had been isolated. The regulators of autolysis, with an exception of the preparation from E. coli, inhibited the activity of B. subtilis extracellular lytic enzymes in the course of their action on E. coli cells. The possibility for using the regulators of autolysis in microbiological processes is discussed.     

The MPI Emotional Body Expressions Database for Narrative Scenarios

Emotion expression in human-human interaction takes place via various types of information, including body motion. Research on the perceptual-cognitive mechanisms underlying the processing of natural emotional body language can benefit greatly from datasets of natural emotional body expressions that facilitate stimulus manipulation and analysis. The existing databases have so far focused on few emotion categories which display predominantly prototypical, exaggerated emotion expressions. Moreover, many of these databases consist of video recordings which limit the ability to manipulate and analyse the physical properties of these stimuli. We present a new database consisting of a large set (over 1400) of natural emotional body expressions typical of monologues. To achieve close-to-natural emotional body expressions, amateur actors were narrating coherent stories while their body movements were recorded with motion capture technology. The resulting 3-dimensional motion data recorded at a high frame rate (120 frames per second) provides fine-grained information about body movements and allows the manipulation of movement on a body joint basis. For each expression it gives the positions and orientations in space of 23 body joints for every frame. We report the results of physical motion properties analysis and of an emotion categorisation study. The reactions of observers from the emotion categorisation study are included in the database. Moreover, we recorded the intended emotion expression for each motion sequence from the actor to allow for investigations regarding the link between intended and perceived emotions. The motion sequences along with the accompanying information are made available in a searchable MPI Emotional Body Expression Database. We hope that this database will enable researchers to study expression and perception of naturally occurring emotional body expressions in greater depth.     

Multiple Roles of Peroxiredoxins in Inflammation

Inflammation is a pathophysiological response to infection or tissue damage during which high levels of reactive oxygen and nitrogen species are produced by phagocytes to kill microorganisms. Reactive oxygen and nitrogen species serve also in the complex regulation of inflammatory processes. Recently, it has been proposed that peroxiredoxins may play key roles in innate immunity and inflammation. Indeed, peroxiredoxins are evolutionarily conserved peroxidases able to reduce, with high rate constants, hydrogen peroxide, alkyl hydroperoxides and peroxynitrite which are generated during inflammation. In this minireview, we point out different possible roles of peroxiredoxins during inflammatory processes such as cytoprotective enzymes against oxidative stress, modulators of redox signaling, and extracellular pathogen- or damage-associated molecular patterns. A better understanding of peroxiredoxin functions in inflammation could lead to the discovery of new therapeutic targets.     

Experimental evaluation of the effectiveness of wound dressings based on biologically active substances from marine hydrobionts

This article presents the experimental data on the testing of new wound dressings, viz., porous plates, prepared on the basis of chitosan and calcium alginate that contain biologically active substances (BASs) derived from marine hydrobionts. In a burn wound model in guinea pigs, we revealed a positive effect of tested samples of wound dressings on the wound-healing process; the data of planimetric and pathomorphological studies showing the acceleration of the process of regeneration in the wound are discussed. It was noted that the dynamics and patomorphological characteristics of the wound healing process differed depending on the structure of the BAS included into the composition of wound dressings (peptides, sulfated polysaccharides, a complex of amino acids and peptides).     

The Origin of the Achiasmatic XY Sex Chromosome System in Cacopsylla peregrina (Frst.) (Psylloidea, Homoptera)

The status of an extra univalent, if it is a B chromosome or an achiasmatic Y chromosome, associating with the X chromosome in male meiosis of Cacopsylla peregrina (Frst.) (Homoptera, Psylloidea) was analysed. One extra univalent was present in all males collected from three geographically well separated populations, it was mitotically stable, and showed precise segregation from the X chromosome. These findings led us to propose that the univalent represents in fact a Y chromosome. The behaviour of the X and Y chromosomes during meiotic prophase suggested that their regular segregation was based on an achiasmatic segregation mechanism characterised by a 'touch and go' pairing of segregating chromosomes at metaphase I. To explain the formation of the achiasmatic Y within an insect group with X0 sex chromosome system, it was suggested that the Y chromosome has evolved from a mitotically stable B chromosome that was first integrated into an achiasmatic segregation system with the X chromosome, and has later become fixed in the karyotype as a Y chromosome.     

Phylogeography of red deer (Cervus elaphus): Analysis of MtDNA cytochrome b polymorphism

Analysis of MtDNA cytochrome b gene (1140 bp) polymorphism of 106 samples red deer (Cervus elaphus) from different regions of Eurasia was performed; the phylogenetic relationships of groups throughout the entire inhibiting area (including North America) were reconstructed. Totally 75 haplotypes were detected, 33 of which were found in the European and 42 in the Asian part of the area. There were no identical haplotypes for these two parts of the area found. The close relatedness between Siberian red deer (C. e. sibirica) and North American wapiti (C. e. canadensis) was confirmed. Red deer inhibiting Yakutia were close to the Siberian red deer from Altai and Tuva, whereas red deer inhibiting Krasnoyarsk and Irkutsk regions formed a separate clade. Overall, the reconstructed phylogeographic pattern of the species was significantly different from the subspecies differentiation based on morphological traits.