Alterations in the social-conditioned place preference and density of dopaminergic neurons in the ventral tegmental area in Clsnt2-KO mice.

The incidence of autistic spectrum disorders (ASD) constantly increases in the world. Studying the mechanisms underlying ASD as well as searching for new therapeutic targets are crucial tasks. Many researchers agree that autism is a neurodevelopmental disorder. Clstn2-KO mouse strain with a knockout of calsyntenin 2 gene (Clstn2) is model for investigating ASD. This study aims to evaluate the social-conditioned place preference as well as density of dopaminergic (DA) neurons in the ventral tegmental area (VTA), which belongs to the brain reward system, in the males of the Clstn2-KO strain using wild type C57BL/6J males as controls. Social-conditioned place preference test evaluates a reward-dependent component of social behavior. The results of this test revealed differences between the Clstn2-KO and the control males, as the former did not value socializing with the familiar partner, spending equal time in the isolation- and socializing-associated compartments. The Clstn2-KO group entered both compartments more frequently, but spent less time in the socializing-associated compartment compared to the controls. By contrast, the control males of the C57BL/6J strain spent more time in socializing-associated compartment and less time in the compartment that was associated with loneness. At the same time, an increased number of DA and possibly GABA neurons labeled with antibodies against the type 2 dopamine receptor as well as against tyrosine hydroxylase were detected in the VTA of the Clstn2-KO mice. Thus, a change in social-conditioned place preference in Clstn2-KO mice as well as a higher number of neurons expressing type 2 dopamine receptors and tyrosine hydroxylase in the VTA, the key structure of the mesolimbic dopaminergic pathway, were observed.

Neuronal density in the brain cortex and hippocampus in Clsnt2-KO mouse strain modeling autistic spectrum disorder.

Autistic spectrum disorders (ASD) represent conditions starting in childhood, which are characterized by diff iculties with social interaction and communication, as well as non-typical and stereotyping models of behavior. The mechanisms and the origin of these disorders are not yet understood and thus far there is a lack of prophylactic measures for these disorders. The current study aims to estimate neuronal density in the prefrontal cortex and four hippocampal subf ields, i. e. СA1, СA2, СA3, and DG in Clstn2-KO mice as a genetic model of ASD. In addition, the level of neurogenesis was measured in the DG area of the hippocampus. This mouse strain was obtained by a knockout of the calsinthenin-2 gene (Clsnt2) in C57BL/6J mice; the latter (wild type) was used as controls. To estimate neuronal density, serial sections were prepared on a cryotome for the above-mentioned brain structures with the subsequent immunohistochemical labeling and confocal microscopy; the neuronal marker (anti-NeuN) was used as the primary antibody. In addition, neurogenesis was estimated in the DG region of the hippocampus; for this purpose, a primary antibody against doublecortin (anti-DCX) was used. In all cases Goat anti-rabbit IgG was used as the secondary antibody. The density of neurons in the CA1 region of the hippocampus was lower in Clstn2-KO mice of both sexes as compared with controls. Moreover, in males of both strains, neuronal density in this region was lower as compared to females. Besides, the differences between males and females were revealed in two other hippocampal regions. In the CA2 region, a lower density of neurons was observed in males of both strains, and in the CA3 region, a lower density of neurons was also observed in males as compared to females but only in C57BL/6J mice. No difference between the studied groups was revealed in neurogenesis, nor was it in neuronal density in the prefrontal cortex or DG hippocampal region. Our new f indings indicate that calsyntenin-2 regulates neuronal hippocampal density in subf ield-specif ic manner, suggesting that the CA1 neuronal subpopulation may represent a cellular target for early-life preventive therapy of ASD.

Peculiarities of the Composition of Peripheral Immune Cells and Cytokine Profile in Brain Structures in Mutant DISC1-L100P Mice.

Intact Disc1-L100P mice carrying a point mutation DISC1Rgsc1390 in the second exon of the DISC1 gene (genetic model of schizophrenia) differ from the parental C57BL/6NCrl strain by higher content of CD3+ T cells and reduced number of CD19+B cells in the peripheral blood and spleen. Analysis of T cell subpopulations revealed an increase in the number of CD3+CD4+ T helpers in the blood of mutant mice and a decrease in the level of CD3+CD8+ suppressor/cytotoxic T cells and CD3+CD4+CD25+ T-regulatory cells. The distribution pattern of inflammatory (IL-1ß, IL-2, IL-6, IL-17, IFNγ, and TNFα) and anti-inflammatory (IL-4, IL-10) cytokines specific for Disc1-L100P mice was revealed in the brain structures involved in the pathogenesis of schizophrenia. A possible implication of immune mechanisms in the development of schizophrenia-like endophenotype of Disc1-L100P mice is discussed.

Regenerative Potential of a Suspension and Spheroids of Multipotent Mesenchymal Stromal Cells from Human Umbilical Cord on the Model of Myocardial Infarction in Rats.

Regenerative potential of multipotent mesenchymal stromal cells from the human umbilical cord (MMSC-UC) in the suspension and spheroid form was revealed during the progression of experimental small focal myocardial infarction in rats. In isoproterenol-induced myocardial infarction, foci of necrosis and inflammatory infiltrate and at later terms fibrosis foci were found mainly in the left ventricle of rat heart. In rats receiving MMSC-UC, destructive changes in the myocardium, fibrous scars, and inflammatory process were less pronounced. MMSC-UC also contributed to normalization of the morphofunctional parameters of the heart. Spheroids exhibited higher efficiency in comparison with cell suspension.

The composition of peripheral immunocompetent cell subpopulations and cytokine content in the brain structures of mutant Disc1-Q31L mice.

The DISC1 (disrupted in sсhizophrenia 1) gene is associated with brain dysfunctions, which are involved in a variety of mental disorders, such as schizophrenia, depression and bipolar disorder. This is the first study to examine the immune parameters in Disc1-Q31L mice with a point mutation in the second exon of the DISC1 gene compared to mice of the C57BL/6NCrl strain (WT, wild type). A flow cytometry assay has shown that intact Disc1- Q31L mice differ from the WT strain by an increase in the percentage of CD3+ T cells, CD3+CD4+ Т helper cells and CD3+CD4+CD25+ T regulatory cells and a decrease in CD3+CD8+ T cytotoxic/suppressor cells in the peripheral blood. A multiplex analysis revealed differences in the content of cytokines in the brain structures of Disc1-Q31L mice compared to WT mice. The content of pro-inflammatory cytokines was increased in the frontal cortex (IL-6, IL- 17 and IFNγ) and striatum (IFNγ), and decreased in the hippocampus and hypothalamus. At the same time, the levels of IL-1ß were decreased in all structures being examined. In addition, the content of anti-inflammatory cytokines IL-4 was increased in the frontal cortex, while IL-10 amount was decreased in the hippocampus. Immune response to sheep red blood cells analyzed by the number of antibody-forming cells in the spleen was higher in Disc1-Q31L mice at the peak of the reaction than in WT mice. Thus, Disc1-Q31L mice are characterized by changes in the pattern of cytokines in the brain structures, an amplification of the peripheral T-cell link with an increase in the content of the subpopulations of CD3+CD4+ T helpers and CD3+CD4+CD25+ T regulatory cells, as well as elevated immune reactivity to antigen in the spleen.

Effects of Specific Inhibitor of Phosphodiesterase 7 at the Late Stage of Long-Term Potentiation in Murine Hippocampal Slices.

Second messengers cAMP and cGMP play an important role in synaptic plasticity and memory consolidation. The inhibitors of phosphodiesterases, enzymes hydrolyzing these cyclic nucleotides, are actively studied as potential drugs for the treatment of various cognitive disorders and depression. We studied the effects of a new inhibitor of phosphodiesterase 7 AGF2.20 on the formation of long-term potentiation in hippocampal slices. Administration of AGF2.20 (10 nM) in 90 min after weak tetanization prevented a decrease in the amplitude of excitatory post-synaptic potentials and stabilized long-term potentiation. These data attest to the involvement of phosphodiesterase 7 in the development of synaptic plasticity in the hippocampus. The inhibitor AGF2.20 is considered for the further analysis as a promising substance for the treatment of cognitive impairments.

Age-related adaptive responses of mitochondria of the retinal pigment epithelium to the everyday blue LED lighting.

The effect of everyday blue light (λ = 440-460 nm) on mitochondria of the retinal pigment epithelium of different age groups of Japanese quail was studied using electron microscopy, morphometric methods, and biochemical analysis. We have found a significant increase in the number of mitochondria, including those modified, mainly in young birds. In addition, cell metabolic activity increased in response to blue lighting. These changes are assumed to reflect an adaptive response of mitochondria aimed at neutralizing the phototoxic effect of blue light caused by accumulation of lipofuscin granules.

Features of emotional and social behavioral phenotypes of calsyntenin2 knockout mice.

Calsyntenin-2 (Clstn2) is the synaptic protein that belongs to the super family of cadherins, playing an important role in learning and memory. We recently reported that Clstn2 knockout mice (Clstn2-KO) have a deficit of GABAergic interneurons coupled with hyperactivity and deficient spatial memory. Given, that impaired functioning of GABA receptors is linked to several psychopathologies, including anxiety and autism, we sought to further characterize Clstn2-KO mice with respect to emotional and social behavior. Clstn2-KO males and females were tested in the elevated plus-maze (EPM), open field (OF), forced swim test, social affiliation and recognition test, social transmission of food preference (STFP), dyadic social interactions and marble burying test. Clstn2-KO mice demonstrated high exploration and hyperactivity in the dimly lit EPM that affect anxiety parameters. In contrast, in a more adverse situation in the OF have increased emotionality in Clstn2-KO males, not females. Assessment of hyperactivity for prolong period in the OF showed that Clstn2-KO animals were able to decline their hyperactivity, but their ambulation still remained higher than in WT littermates. Additionally, Clstn2-KO mice expressed stereotyped behavior. Strikingly, analysis of social behavior identified deficient social motivation and social recognition only in Clstn2-KO males, but not in females. Further analysis of social communication in the STFP and direct observation of agonistic interactions confirmed the reduced social behavior in Clstn2-KO males. Altogether, current results showed Clstn2 gene and sex interactions on socio-emotional performance in mice, suggesting a possible role of calsyntenin2 in psychopathological mechanisms of autism.

[Electron microscope analysis of cardiomyocytes in the rat left ventricle under simulation of weightlessness effects and artificial gravitation].

Electron microscopic study of left ventricle cardiomyocytes and quantitative analysis of their mitochondriom was performed in rats exposed to tail-suspension, as a model of weightlessness effects, to artificial gravity produced by intermittent 2G centrifugation and a combination of these effects. It was found that the cardiomyocytes ultrastructure changed slightly after tail-suspension and after intermittent 2G influence, as well as under a combination of these effects. However, the number of intermitochondrial junctions increased significantly in the interfibrillar zone of cardiomyocytes under a combination of tail-suspension and intermittent 2G influence, which agrees with the cell hypertrophy described earlier.

Enhanced dopamine function in DISC1-L100P mutant mice: implications for schizophrenia.

Significant advances have been made in understanding the role of disrupted-in-schizophrenia-1 (DISC1) in the brain and accumulating findings suggest the possible implication of DISC1 in the regulation of dopamine (DA) function. A mutation in the second exon of DISC1 at L100P leads to the development of schizophrenia-related behavior in mutant mice (DISC1-L100P). We investigated here the role of DA in the expression of schizophrenia-related endophenotypes in the DISC1-L100P genetic mouse model. The mutated DISC1 resulted in facilitation of the psychostimulant effect of amphetamine in DISC1-L100P mutant mice assessed in the open field and prepulse inhibition (PPI) tests. Biochemical studies detected a 2.1-fold increase in the proportion of striatal D receptors without significant changes in DA release in vivo in the striatum of DISC1-L100P mutants in response to the low dose of amphetamine. The D(2) receptor antagonist haloperidol reversed the hyperactivity, PPI and latent inhibition (LI) deficits and blocked the psychostimulant effect of amphetamine in DISC1-L100P mutants. Taken together, our findings show the role of DISC1 in D(2) -related pathophysiological mechanism of schizophrenia, linking DISC1 with well-established DA hypothesis of schizophrenia.

[Effect of sulpiride on immobility reflex and pinch-induced catalepsy in CBA/Lac male mice with various social status].

This study was aimed to determine the effect of D2/D3 receptor antagonist sulpiride on the expression of immobility reflex ("pinch-test") and pinch-induced catalepsy ("bar-test") of CBA/Lac male mice depending on their social status ("aggressors" with repeated experience of victories or a "losers" with repeated experience of social defeats). Sulpiride (20 mg/kg, i.p.) was acutely administered to "aggressors" and "losers" after 10 and 20 daily social contacts (victories or social defeats) and to a control group of male mice. Repeated experience of social victories and defeats altered the immobility duration in both tests and modified the expression of the sulpiride effect. In the pinch-tets, the duration of immobility was longer in "loosers" than in "aggressors". In the bar-test, the pinch-induced catalepsy was more expressed in "losers" and "aggressors" as compared to control. Sulpiride was more effective in increasing immobility of"aggressors" and had a weaker effect on the control and "losers". Therefore, the effect of sulpiride is affected by the social status of the animals.

[Protective effect of lornoxicam on development of myocardial infarction in rats under conditions of ischemia and ischemia-reperfusion].

Activation of inflammation and enzyme cyclooxygenase with formation of proinflammatory prostaglandins is a key element of development of myocardial infarction in patients with acute coronary syndrome. Basing on literature data and own experience we suggested that single intravenous injection of 230 mg/kg of nonselective inhibitor of type 1 and 2 cyclooxygenase lornaxicam in the phase of initialization of inflammation 20 min after onset of ischemia would lead to reduction of myocardial infarction volume in rats in irreversible ischemia and ischemia with subsequent reperfusion. The conducted study allowed to reveal that administration of lornoxicam in recommended for human use dose lowered mortality of animals and increased number of capillaries per one cardiomyocyte in case of irreversible coronary artery occlusion. In ischemia-reperfusion as in irreversible myocardial ischemia lornoxicam reduced volume of necrosis and degree of thinning of left ventricular wall in the region of infarction, and lowered volume of connective tissue in periinfarction zone of the myocardium in remote period.

[The study of exploratory behavior in CBA/Lac male mice under influence of positive and negative social interactions].

The exploratory activity towards a new object placed in the home cage was studied in CBA/Lac male mice after their repeated daily social victories and defeats. After 10 daily social defeats, submissive mice displayed a significantly declined exploration of a new object, whereas aggressive mice with experience of 10 daily victories expressed only a mild decrease in exploratory activity (as compared to control). Twenty daily social defeats almost completely abolished exploratory behavior in submissive mice, whereas 20 daily victories resulted in the increased exploration of a new object in aggressive mice. It is suggested that repeated social defeats associated with the negative psychoemotional state lead to the development of a pronounced exploratory motivational deficit. On the other hand, the experience of repeated daily aggression forms the enhanced motivational excitement that prevents a relevant response to a neutral stimulus.

[Protective effect of peptide semax the rat heart in acute myocardial infarction].

Semax, a member of ACTH-derived peptides family, has been employed in the treatment of acute ischemic stroke in patients. It decreased neurological deficit and reduced NO hyperproduction in the rat brain, caused by acute cerebral hypoperfusion. We suggested that semax is also able to protect rat heart from ischemic damage in acute myocardial infaction (AMI). AMI was induced by left coronary artery occlusion, myocardial ischemic area averaged 30 % of left ventricle. In 2 hours after coronary occlusion, the AMI group developed 11 % reduced mean arterial blood pressure and 48 % increased diastolic blood pressure in left ventricle in comparison with sham-operated control group. However, infusion of either dobutamine, which directly stimulates myocardial contractility, or sodium nitroprusside and phenylephrine, that change vascular resistance and thus cardiac afterload, did not reveal distinctions in hemodynamic parameters between groups. These data indicate absense or only moderate cardiac dysfunction in rats with AMI and are consistent wih morphometrical and histochemical studies that did not detect any necrotic or apoptotic (TUNEL-test) changes in left ventricular cardiomyocytes in spite of development of distinct ischemic disturbances of mitochondria and nuclear in about 50 % of cardiomyocytes in 2 hours after AMI. Semax (150 microg/kg), given i. p. 15 min and 2 hours after coronary occlusion, caused no effect on cardiac function, but completely prevented ischemia-induced ultrastructural changes of cardiomyocytes. This protective effect was accompanied by the ability of peptide to blunt the increase in plasma concentrations of nitrates, observed in AMI group.

[Protective effect of peptide semax (ACTH(4-7)Pro-Gly-Pro) on the rat heart rate after myocardial infarction].

Semax, a member of ACTH-derived peptides family, was used in treatment of ischemic stroke in patients. It decreased neurological deficiency and reduced NO hyperproduction in the rat brain caused by acute cerebral hypoperfusion. We suggest that semax is also capable of protecting the rat heart from ischemic damage 28 days after myocardial infarction (MI) induced by left descendent coronary artery occlusion. Semax (150 microg/kg) was given i. p. in the operating day twice: 15 min and 2 hours after coronary occlusion, and once a day for the following 6 days. In 28 days after infarction, the MI group developed cardiac hypertrophy, cell growth was caused mainly by the increase of contractile filaments not supported by the appropriate mitochondrial growth that indicated an impaired energy supply of the cells. Moreover, cardiac hypertrophy was accompanied by decreased mean arterial blood pressure and cardiac contractile function and increased left ventricular end-diastolic pressure. Pharmacological change of cardiac afterload revealed that, in 28 days after MI, the rat heart was not able to change its contractile performance in response to either increase or decrease of systemic blood pressure, and as a result could not maintain its diastolic pressure. All these changes obviously reflect development of heart failure. Semax did not affect cardiac work but partially prevented end-diastolic pressure growth in left ventricle as well as ameliorated cardiomyocyte hypertrophy and disproportionate growth of contractile and mitochondrial apparatus, thus exerting beneficial effect on the left ventricular remodeling and heart failure development late after myocardial infarction.

[Dynamic changes of brain serotonergic and dopaminergic activities during development of anxious depression: experimental study]. / Dinamicheskue izmeneniia serotonergicheskoi i dofaminergicheskoi aktivnosti mozga v protsesse razvitiia trevozhnoi depressii: éksperimental'noe issledovanie.

Chronic psychoemotional stress of social defeats produces development of experimental anxious depression in male mice similar to this disorder in humans. 5-HT and 5-HIAA levels, TPH and MAO A activities, 5-HT1A-receptors in different brain areas were investigated at different stages of development of experimental disorder. It has been shown that initial stage (3 days of social stress) is accompanied by increase of 5-HT level in some brain areas. Decreased 5-HIAA levels in the hippocampus, amygdala and nucleus accumbens were discovered at the stage of forming depression (10 days of social stress). Pharmacological desensitisation and decreased number of 5-HT1A-receptors were shown in frontal cortex and amygdala. At the stage of pronounced depression (20 days of stress), there were no differences in 5-HT and 5-HIAA levels in all brain areas (excluding hypothalamus) of depressive animals. However increased number of 5-HT1A-receptors and decreased affinity in amygdala and decreased TPH and MAOA activities in hippocampus were found in depressive mice. Hypofunction of serotonergic system is suggested at the stage of pronounced depression state in animals. Similar processes had place in brain dopaminergic systems. It is concluded that dynamic changes of brain monoaminergic activities accompany the development of anxious depression in animals. Various parameters of monoaminergic systems are differently changed depending on brain area, mediator system and stage of disorder.

Electron microscopic study of left ventricular cardiomyocyte mitochondriom in rats subjected to head-down tilt.

The mitochondriom of left-ventricular cardiomyocytes in rats subjected to head-down tilt was studied at the electron microscopic level. The ultrastructure of individual mitochondria was disturbed and the number of intermitochondrial contacts in the perinuclear zone increased after 30-day head-down tilt. These parameters did not return to normal over 30 days after 30-day tilt. Repeated 14-day head-down tilt led to a more pronounced increase in the number of intermitochondrial contacts, mitochondria with abnormal ultrastructure were still observed.