Behavioral phenotyping of mice deficient for tumor necrosis factor

The tumor necrosis factor (TNF) is a cytokine exerting both homeostatic and pathophysiological roles in the central nervous system (CNS). It has been demonstrated that TNF plays roles in such diseases as Alzheimer’s disease, Parkinson’s disease and multiple sclerosis. Nevertheless, the role of TNF in the CNS under normal physiological conditions is poorly studied. A novel mouse strain with TNF deficiency (TNFKO) was developed in S.A. Nedospa­sov’s labora­tory of Engelhardt Institute of Molecular Bio­logy of the Russian Academy of Sciences on the C57Bl/6 (WT) background. In our study, we compared the behavior of TNFKO and WT adult mice in a battery of tests: open-field, elevated plus-maze and the forced-swim test. We showed that TNF deficiency had no effect on locomotor activity or exploration in the openfield test. At the same time, in this test, TNFKO mice spent more time in the center of the arena, but had a higher level of defecation and lower rearing duration. This result indicates that, in the openfield conditions, TNFKO mice show disorientation rather than anxiety-like behavior. There were no differences between TNFKO and WT in anxiety level in the elevated plus-maze test or in depressive-like behavior in the forcedswim test. These data suggest that TNF deficiency leads to changes in neurofunctional interactions that alter the mouse response to mild stress in the open-field test

Conducting and automating the water Morris maze test in SPF conditions

The water Morris maze is the basic test to study the spatial ability to learn as well as spatial memory in laboratory rodents. It is a part of a series of tests necessary for behavioral phenotyping of mutant and transgenic mice. At the same time, conducting this test in SPF conditions must comply with very strict regulations concerning pathogen control. A white animal on the surface of whitened water is low contrast and this does not allow the animal to be traced automatically, which represents yet another major problem. A unique installation based on EthoStudio has been developed at the Institute of Cytology and Genetics SB RAS and the Institute of Automation and Electrometry SB RAS. This installation automates the process of tracing mice of any coat color in SPF conditions. This includes a setup to install a plastic water reservoir (110×40 cm), a digital camera and a light source. Water to fill the reservoir was sterilized using a Van Erp Blue Lagoon UV-C Tech 15000 ultraviolet decontaminator. The image of an animal was processed in a frame-by-frame fashion using the EthoStudio program, with the following parameters calculated: latent release time, route covered, cumulative distance to the platform and the time spent in the reservoir sectors. With this installation, we were able to study the spatial ability to learn and spatial memory in mice of the C57BL/6 strain and in mice of the C57BL/6/ Kaiso strain developed on the C57BL/6 background, with the gene encoding the methyl-DNA binding Kaiso protein knocked-out. It has been demonstrated that mice of these strains are able to learn to find the platform in the water Morris maze and have the location of the platform in their memory for at least the next four days

Effect of lethal yellow (AY) mutation and photoperiod alterations on mouse behavior

Decrease in natural illumination in fall/winter months causes depressive-like seasonal affective disorders in vulnerable individuals. Obesity is another risk factor of depression. The lethal yellow (AY) mutation causes ectopic expression of agouti protein in the brain. Mice heterozygous for AY mutation (AY/a) are obese compared to their wild-type littermates (a/a). The main aims of the study were to investigate the effects of AY mutation, photoperiod and the interaction between these factors on daily activity dynamics, feeding, locomotor and exploratory activities, anxiety-related and depressive-like behaviors in mild stress condition. Six weeks old mouse males of AY/a and a/a lines were divided into four groups eight animals each and exposed to long- (14 h light and 10 h darkness) or short- (4 h light and 20 h darkness) day conditions for 28 days. Then the behavior of these mice was successively investigated in the home cage, open field, elevated plus-maze and forced swim tests. We did not observed any effect of AY mutation on the general activity, water and food consumption in the home cage; locomotion and exploration in the open field test; anxiety-related behavior in the open field and elevated plus-maze tests. At the same time, AY mutation increased depressive-like immobility time in the forced swim test (F1.28 = 20.03, p = 0.00012). Shortday conditions decreased nocturnal activity in the home cage, as well as locomotion (F1.28 = 16.33, p = 0.0004) and exploration (F1.28 = 16.24, p < 0.0004) in the open field test. Moreover, short-day exposition decreased time spent in the center of the open field (F1.28 = 6.57, p = 0.016) and in the open arms of the elevated plus-maze (F1.28 = 12.08, p = 0.0017) tests and increased immobility time in the forced swim test (F1.28 = 9.95, p = 0.0038). However, no effect of the interaction between AY mutation and photoperiod on immobility time in the forced swim test was observed. Therefore, short-day photoperiod and AY mutation increased depressive-like behavior in the forced swim test by means of different mechanisms

Submillimeter ESR spectra of Fe²⁺ ions in synthetic and natural beryl crystals

© 2017, Pleiades Publishing, Ltd. Electron spin resonance spectra of non-Kramers bivalent iron (Fe 2+ ) ions have been detected in synthetic and natural beryl crystals with an iron impurity. The observed ESR spectra have been attributed to resonance transitions of Fe 2+ ions from the ground (singlet) state to excited (doublet) levels with the splitting Δ = 12.7 cm –1 between the levels. The experimental angular and frequency dependences of the resonance field of the ESR signal have been described by the spin Hamiltonian with the effective spin S = 1. The analysis of the ESR data and optical absorption spectra indicates that the Fe 2+ ions are situated in tetrahedral positions and substitute Be 2+ cations in the beryl structure

The United States Congress and nuclear war powers: explaining legislative nonfeasance

Scholarly debate over the role of the United States Congress in approving military action has focused on the respective war powers granted the executive and legislature by the United States Constitution. Although a voluminous literature has examined the institutional and partisan politics shaping their exercise, a conspicuous lacuna concerns nuclear war powers. Despite periodic but mostly ineffective reassertions of congressional prerogatives over war, the decision to employ nuclear weapons has been left entirely to presidential discretion since 1945. Explaining this consistent refusal by Congress to rein in the ultimate presidential power and exercise co-responsibility for the most devastating form of war relies less on disputatious constitutional grounds than on three arguments about congressional dysfunctionality, legislative irresponsibility, and the relative costs of collective action by federal lawmakers on perilous national security questions

EFFECT OF TUMOR NECROSIS FACTOR DEFICIENCY ON BEHAVIOR AND METABOLISM OF BIOGENIC AMINES IN BRAIN

In this study, we investigated the effect of knockout of tumor necrosis factor (TNF) gene on behavior and metabolism of biogenic amines in the brain. It was shown that knockout mice spend less time in Morris water maze in the sector where the platform was previously during probe trial. In the “novel object test” knockout mice sniff “object” less time than wild type mice. Furthermore, it was shown that the levels of 5-HIAA in the midbrain, the hippocampus and olfactory bulb significantly higher in knockout mice than in wild type mice

Optimisation method for automatic selection of rate constants of global reaction mechanisms

Optimisation approach to automate selection of global reaction mechanisms rate constants is proposed and studied. The objective of optimisation is to find reaction rate constants minimising deviation of some flame characteristics (e.g. laminar burning velocity, ignition delay time, etc.) calculated by global mechanism from their reference values known from experiments or computed by detailed mechanisms. Examples of one, two and four step mechanisms optimisation with respect to laminar burning velocity and concentration distributions in counterflow diffusion flame are given. Computer codes implementing optimisation algorithm for these examples are also afforded and can be modified and used for reaction constants selection in various applications. Uniqueness of singlecriteria and multicriteria optimisation solutions is studied numerically by computations with different initial guesses and by direct evaluation of the objective functions. Particularly, it is found that for considered global mechanisms the minimum value of objective function is reached in some subdomain of the parametric space. This means that any values of rate parameters from this subdomain results in almost the same deviations of chosen flame characteristic from its reference value.</p

Submillimeter ESR spectra of Fe²⁺ ions in synthetic and natural beryl crystals

© 2017, Pleiades Publishing, Ltd. Electron spin resonance spectra of non-Kramers bivalent iron (Fe 2+ ) ions have been detected in synthetic and natural beryl crystals with an iron impurity. The observed ESR spectra have been attributed to resonance transitions of Fe 2+ ions from the ground (singlet) state to excited (doublet) levels with the splitting Δ = 12.7 cm –1 between the levels. The experimental angular and frequency dependences of the resonance field of the ESR signal have been described by the spin Hamiltonian with the effective spin S = 1. The analysis of the ESR data and optical absorption spectra indicates that the Fe 2+ ions are situated in tetrahedral positions and substitute Be 2+ cations in the beryl structure

Submillimeter ESR spectra of Fe²⁺ ions in synthetic and natural beryl crystals

© 2017, Pleiades Publishing, Ltd. Electron spin resonance spectra of non-Kramers bivalent iron (Fe 2+ ) ions have been detected in synthetic and natural beryl crystals with an iron impurity. The observed ESR spectra have been attributed to resonance transitions of Fe 2+ ions from the ground (singlet) state to excited (doublet) levels with the splitting Δ = 12.7 cm –1 between the levels. The experimental angular and frequency dependences of the resonance field of the ESR signal have been described by the spin Hamiltonian with the effective spin S = 1. The analysis of the ESR data and optical absorption spectra indicates that the Fe 2+ ions are situated in tetrahedral positions and substitute Be 2+ cations in the beryl structure