Transfer of optogenetic vectors into the brain of neonatal animals to study neuron functions during subsequent periods of development

Optogenetics, that is, the control of cell activity using light-sensitive ion channels opsins with light of a specific wavelength, is increasingly being used to study activities and functions of neurons. Expression of opsins in the cell membrane, followed by the acquisition by the cell of the sensitivity to light is achieved by means of viral vectors, often created on the basis of lentiviral or adeno-associated (AAV) viruses bearing the nucleotide sequence encoding the photo-channel proteins. Inclusion of the cell-specific promoter of interest into the transgene-expression cassette allows opsin to be produced only in the target cells. The aim of this work was to briefly describe the optogenetic method, as well as to analyze the possibility to use administration of viral vectors into the brain of neonatal animals to study the function of neurons in vivo during subsequent periods of development. In this analysis, 3-day-old rat pups received intracerebroventricular injections of optovector (pAAV-CAMKIIa-ChR2h134-YFP), coding for a photo channel, which activates neurons, and the yellow fluorescent marker protein under the CAMKIIa promoter specific for glutamatergic neurons under cold anesthesia. The peak expression of the transferred gene is usually achieved at week 3–5 after the transfer of the vector, which is what was also observed in our experiments. Stimulation of the hippocampal neurons with blue light in the 20-day-old animals, to which opto-vector was transferred at the 3rd day of life, increased the discharge activity of these neurons. This light stimulation increased expression of the recognized marker of neuronal activation protein c-Fos in these photosensitive cells too. The same experiments with older animals, 60 days after the neonatal opto-channel gene transfer, revealed no noticeable expression of this channel or photoactivation of target neurons of the hippocampus. Thus, neonatal administration of a viral vector carrying an opto-channel gene is suitable for the study of brain neurons in rats of juvenile age, and requires additional control for gene expression during subsequent periods of development

Effect of physical activity on structural asymmetry of mouse hippocampus

The relevance of studies of adult neurogenesis is evident in connection with the potential use of these new neurons to replace neurons lost in the process of life. Despite considerable efforts, little is known about the fnal fate of these cells, the functional signifcance of their connections and the regulation of their development. It is known that physical activity signifcantly increases the number of fssile progenitors, the precursors of new neurons in the dentate gyrus of the hippocampus. The existing immunohistochemical methods for labeling new neurons do not allow tracing the temporal dynamics of changes in the volume of brain structures in the same animal, induced by external impacts, such as voluntary exercise. This makes it an urgent task to develop and improve methods for long­term control of changes that occur in the adult hippocampus due to the induction of neurogenesis. The main purpose of this work was to non­invasively track, by using magnetic resonance imaging (MRI), the temporal dynamics of changes in the volume of the hippocampus in the same animals that had voluntary physical activity. It was found that voluntary exercise did not change the total volume of the mouse hippocampus. However, the difference in the volume ratio between the right and left parts of the hippocampus was signifcantly lower compared with the control group. The reconstruction and analysis of protein­protein interactions that ensure the survival of a large number of new neurons and their integration into existing neural networks in the hippocampus have been carried out. The proposed approach allows the non­invasive registration of changes in the ratio of the volumes of these paired brain structures

Learning-induced sensory plasticity of mouse olfactory epithelium

Traditionally, studies of the neurobiology of learning and memory focus on the circuitry that interfaces between sensory inputs and behavioral outputs, such as the amygdala and cerebellum. However, evidence is accumulating that some forms of learning can in fact drive stimulus­specifc changes very early in sensory systems, including not only primary sensory cortices but also precortical structures and even the peripheral sensory organs themselves. In this study, we investigated the effect of olfactory associative training on the functional activity of olfactory epithelium neurons in response to an indifferent stimulus (orange oil). It was found that such a peripheral structure of the olfactory system of adult mice as the olfactory epithelium (OE) demonstrates experience­dependent plasticity. In our experiment, associative learning led to changes in the patterns of OE cell activation in response to orange oil in comparison with the control group and animals that were given odor without reinforcement. To interpret the results obtained, we compared the distribution of MRI contrast across the zones of OE in response to a conditioned odor in trained animals and in control animals that were given orange oil at three concentrations: original (used for conditioning), 4­fold higher and 4­fold lower. Since the OE activation patterns obtained coincided in the group of trained animals and controls, which were stimulated with orange oil at the 4­fold higher concentration, it can be concluded that associative conditioning increased the sensitivity of the OE to the conditioned stimulus. The observed increase in OE response to orange oil may be the result of neurogenesis, i. e. the maturation of new olfactory neurons responsive to this stimulus, or the consequence of an increase in individual sensitivity of each OE neuron. Based on data of MRI contrast accumulation in mouse OE, the sensory plasticity way in learning­induced increase in sensitivity of OE to conditioned stimulus is more possible. Thus, the sensory plasticity of the OE plays a signifcant role in the formation of the neuronal response to the provision of an initially indifferent odor and is part of the adaptive responses to the environmental changing

A supersonic laser ablation beam source with narrow velocity spreads

A supersonic beam source for SrF and BaF molecules is constructed by combining the expansion of carrier gas (a mixture of 2% SF6 and 98% argon) from an Even-Lavie valve with laser ablation of a barium/strontium metal target at a repetition rate of 10 Hz. Molecular beams with a narrow translational velocity spread are produced at relative values of Δv/v = 0.053(11) and 0.054(9) for SrF and BaF, respectively. The relative velocity spread of the beams produced in our source is lower in comparison with the results from other metal fluoride beams produced in supersonic laser ablation sources. The rotational temperature of BaF is measured to be 3.5 K. The source produces 6 × 108 and 107 molecules per steradian per pulse in the X2ς+ (ν = 0, N = 1) state of BaF and SrF molecules, respectively, a state amenable to Stark deceleration and laser cooling

Lifetime measurements of the A (2)Pi(1/2) and A (2)Pi(3/2) states in BaF

Time resolved detection of laser induced fluorescence from pulsed excitation of electronic states in barium monofluoride (BaF) molecules has been performed in order to determine the lifetimes of the $A^2\Pi_{1/2}$ and $A^2\Pi_{3/2}$ states. The method permits control over experimental parameters such that systematic biases in the interpretation of the data can be controlled to below $10^{-3}$ relative accuracy. The statistically limited values for the lifetimes of the $A^2\Pi_{1/2}(\nu=0)$ and $A^2\Pi_{3/2}(\nu=0)$ states are 57.1(3) ns and 47.9(7)~ns, respectively. The ratio of these values is in good agreement with scaling for the different excitation energies. The investigated molecular states are of relevance for an experimental search for a permanent electric dipole moment (EDM) of the electron in BaF

Analysis of Processes with Axisymmetric Plastik Flow of Metals

A numerical method for the analysis of stresses and plastic flow rates is presented for processes with axisymmetric plastic flow of metals. This techniques is based on a representation of yield zones in a special formulation of the stresses related to Iljushin\u27s deviatoric stress space. The basic differential equations describing axisymmetric plastic flow are solved by hyperbolic approximations. In fact, the approach represents an enhanced method of slip lines since the characteristics of the differential equations for stresses and rates coincide with these. This condition is very important for the analysis of damage induced by voids which generate microscopic slip bands. The method is illustrated by an analysis of the forging process of an axisymmetric part made of low-carbon low-alloy steel. The stepwise analysis of deformation allows for calculating the contact load applied to the working tool, the strains accumulated within the part volume, and some "meso-parameters," e.g., the damage induced by strain micro-defects and the internal energy of hardening. Two integral measures connected with the hydrostatic and deviatoric parts of the damage tensor are used for the calculation of strain-induced damage. The predicted damage is significantly less than its permissible value, as high hydrostatic pressure in the plastic zone heals micro-defects, prevents their growth, and, thereby, increases the processing ductility of deformed metals during forging. The research results allow us to give some recommendations for the selection of appropriate processing strains for forging in order to achieve high strength properties of the produced axisymmetric case-shaped parts

Hochgeschwindigkeitsscherschneiden von Stangenmaterial

Rohlinge für das Kaltfließpressen oder Präzisionsschmieden können u.a. mittels Hochgeschwindigkeitsscherschneiden (HGSS) hergestellt werden. Hierdurch wird im Vergleich zum Scheren oder Sägen die Produktivität und Qualität deutlich gesteigert und ein Materialverlust verhindert. Um das HGSS-Verfahren in der praktischen Anwendung weitreichend zu etablieren, sind jedoch die aktuellen Prozesseinsatzgrenzen bezüglich schwer trennbarer Werkstoffe oder des maximalen Halbzeugdurchmessers noch deutlich zu verbessern. Hieraus leitet sich das Forschungsziel der Erweiterung der Prozesseinsatzgrenzen und Steigerung der Energie- und Rohstoffeffizienz beim HGSS ab. In dem Projekt wird ein ganzheitlicher Lösungsweg verfolgt, bei dem eine enge Wechselwirkung zwischen den Werkstoffuntersuchungen im Labor, den Prozessanalysen an der HGSS-Anlage und den numerischen Simulationen besteht. Hierdurch ist es möglich, den Trennvorgang bei hohen Formänderungsgeschwindigkeiten experimentell durchzuführen, numerisch abzubilden bzw. zu untersuchen sowie anschließend zu optimieren. Die angestrebten Ergebnisse in Form der Arbeitsdiagramme, die u.a. bezüglich der Prozesskräfte oder Rohteilqualität mittels Einflussanalysen zu Prozess- und Bauteilparametern bestimmt werden, liefern zurzeit noch fehlendes Wissen zum HGSS. Hierdurch können zukünftig aufwendige Erprobungszyklen zur Dimensionierung und Auslegung von HGSS-Prozessen oder -Werkzeugen entfallen und die Serienreife HGSS-gefertigter Halbzeuge preisgünstiger und schneller erreicht werden. Der Nutzen der KMU folgt nach Umsetzung der Projektergebnisse aus der verbesserten Prozessbeherrschung, der Datenbasis zur Werkzeug- und Maschinenauslegung insbesondere für größere Durchmesser und schwer trennbare Materialien, der Erhöhung der Ausbringungsmenge, der Steigerung der Scherqualität, der Erweiterung des Anwendungspotentials und der Werkstoffauswahl, der Einsparung von prozessspezifischen Zwischenschritten sowie der Verringerung des Energiebedarfs

СОВРЕМЕННОЕ СОСТОЯНИЕ И ПЕРСПЕКТИВЫ РАЗВИТИЯ СУДЕБНО-ВЕТЕРИНАРНОЙ ЭКСПЕРТИЗЫ В УКРАИНЕ

The prospects of development of forensic veterinary examination as areas of practical veterinary and legal activity, science and educational discipline in Ukraine are demonstrated. The subject, the range of objects, the list of issues that are solved while this examination during offences investigation are determined. Some aspects of special veterinary knowledge use in expert activity are considered. Prospective scientific directions of forensic veterinary research are indicated. The subject of forensic veterinary examination are factual data (facts, circumstances) which are established on the basis of special veterinary knowledge. Objects of forensic veterinary examination include: 1) live animals: domestic, wild, hunting, zoo (exotic); 2) corpses of animals (anatomically whole, fragmentary, skeletonized); 3) raw materials for the veterinary and biological industry (endocrine, enzymatic); 4) feeds of animal origin, feed additives; 5) products of animal origin; 6) veterinary pharmaceuticals and poisons; 7) objects – material evidence: pesticides, ropes, vomit masses, blood traces, afterbirth, etc.; derivatives of the skin of animal origin (hair, feather, scales, etc.); pieces of fur and skins; 8) documents: materials of pre-trial and judicial cases (protocols of autopsy, acts of an epizootic inspection of a farm, a journal of registration and treatment of sick animals, a journal of issuing veterinary documents, a manufacturer's declaration, operating permit, etc.). Forensic veterinary examination solves the issues during offences investigation regarding: production, circulation, sale, storage of animal origin products; state determination of health and degree of bodily harm of animals; forensic veterinary research of animal corpses; establishment of violent death; assessment of the timeliness and completeness of medical-prophylactic, antiepizootic, sanitary-hygienic, quarantine and other measures; research on cases of medical errors of specialists in veterinary medicine; performing researches on cases on solving conflicting economic issues in the areas of animal husbandry technology and veterinary medicine; researches on veterinary documents.Показано перспективи розвитку судово-ветеринарної експертизи, як сфери практичної ветеринарної і юридичної діяльності, науки й навчальної дисципліни в Україні. Визначено предмет, коло об’єктів, перелік питань, які вирішуються цією експертизою під час розслідування правопорушень. Розглянуто деякі аспекти використання спеціальних ветеринарних знань в експертній діяльності. Зазначено перспективні наукові напрями судово-ветеринарних досліджень.Показаны перспективы развития судебно-ветеринарной экспертизы, как сферы практической ветеринарной и юридической деятельности, науки и учебной дисциплины в Украине. Определены предмет, круг объектов, перечень вопросов, которые решаются этой экспертизой при расследовании правонарушений. Рассмотрены некоторые аспекты использования специальных ветеринарных знаний в экспертной деятельности. Указаны перспективные научные направления судебно-ветеринарных исследований. Предметом судебно-ветеринарной экспертизы являются фактические данные (факты, обстоятельства), которые устанавливаются на основе специальных ветеринарных знаний. К объектам судебно-ветеринарной экспертизы относятся: 1) животные живые: домашние, дикие, охотничьи, зоопарковые (экзотические); 2) трупы животных (анатомически целые, фрагментарные, скелетонизированные); 3) сырье для ветеринарно-биологической промышленности (эндокринное, ферментное); 4) корма животного происхождения, кормовые добавки; 5) продукция животного происхождения; 6) ветеринарные фармацевтические препараты и яды; 7) объекты – вещественные доказательства: ядохимикаты, веревки, рвотные массы, следы крови, послед и т. п.; производные кожных покровов животного происхождения (волосы, перо, чешуя и т. п.); куски меха и шкуры; 8) документы: материалы досудебных и судебных дел (протоколы вскрытия, акты эпизоотического обследования хозяйства, журнал регистрации и лечения больных животных, журнал выдачи ветеринарных документов, декларация производителя, эксплуатационное разрешение и т. п.). Судебно-ветеринарная экспертиза решает вопросы при расследовании правонарушений относительно: производства, обращения, реализации, хранения продукции животного происхождения; определения состояния здоровья и степени телесных повреждений животных; судебно-ветеринарного исследования трупов животных, установления насильственной смерти; жестокого обращения с животными; оценки своевременности и полноты проведения лечебно-профилактических, противоэпизоотических, санитарно-гигиенических, карантинных и других мероприятий; исследования по делам о врачебных ошибках специалистов ветеринарной медицины; проведения исследований по делам, касающихся решения противоречивых хозяйственных вопросов в сферах технологии животноводства и ветеринарной медицины; исследования ветеринарных документов