[Effects of roncoleukin on immune parameters and mixed anxiety/depression state induced by chronic social defeat stress in male mice].

UNLABELLED: Chronic social defeat stress leads to the development of mixed anxiety-depression state, which accompanied by immune deficiency in male mice. Paper aimed to study effects of ronkoleukin on the parameters of cellular immunity in the thymus and spleen and psychoemotional state in these animals. METHODS: Mixed anxiety/depression state was produced by chronic social defeat stress during 20 days in male mice. Roncoleukin (5000 ME/kg, i/p) and saline were chronically injected to depressive mice during 2 weeks without agonistic interactions. After this period subpopulations of lymphocytes in the thymus and spleen were studied in male mice. The animals were also studied in behavioral tests estimating the levels of communicativeness, anxiety and depressiveness. RESULTS: Roncoleukin decreases the number of lymphocytes in the thymus and spleen, and increased the number of lymphocytes in blood and thymus index. Medication increased per cent of CD4+8+ lymphocytes in the thymus and per cent of CD8+ and CD3+25- lymphocytes in the spleen. Roncoleukin induced anxiogenic, stimulative and antidepressive effects. CONCLUSION: Roncoleukin has small efficacy for treatment of immune suppression induced by chronic social defeat stress and has anxiogenic, stimulating and weak antidepressive effects.

[Changes in immune status induced by repeated aggression in male mice].

It has been shown that psychoneurological disorders are accompanied by different disturbances of immunity. Paper aimed to study the effects of repeated experience of aggression in daily agonistic interactions leading to the development of behavioral psychopathology on the parameters of cellular immunity in the thymus and spleen. There were no found the changes in the weight indexes, the number of cells in the thymus, spleen and blood in aggressive mice. In the spleen of aggressive mice percent of B-lymphocytes--CD19+ and CD16/32+, as well as T-lymphocytes CD4+8-, CD4-8+, and CD4+25(hi) decreased and percent of CD4-25+ increased in comparison with the controls. In the thymus percent of CD4-25+ cells are decreased without changes of other types of lymphocytes. Flow cytometric analysis revealed decreased percentage of apoptotic (A(0)) and resting (G0/G1) cells and increased percentage of proliferating cells in phase S+G2/M in the spleen of aggressive male mice in comparison with the control. The percentage of apoptotic thymocytes is increased and the percentage of thymocytes in S+G2/M phase is decreased under the repeated experience of aggression. Data suggest the possible development of an autoimmune procceses in male mice under the influence of repeated experience of aggression.

[Development of movement disorders in DBA/2J male mice under repeated experience of aggression].

Changes in the behavior of DBA/2J mice after gaining repeated experience of aggression have been investigated. It was shown that the long-term experience of aggression led to development of hyperactivity estimated as increased motor activity in different tests: open field, elevated plus maze and during testing of reaction to a novelty. Symptoms of attention deficit estimated in the "partition" test as a reduction of the communicativeness and the lack of reaction to unfamiliar partner were noticed. Appearance of a large number of hyperkinesis manifested most often in the form of sudden involuntary head movements (jerks) was observed in the behavior of aggressive males during agonistic interactions. Most of the changes in the behavior of DBA/2J mice differed significantly from previously detected in the behavior of aggressive mice of C57BL/6J and CBA/Lac strains, suggesting a significant contribution of heredity that determines the features of behavioral disorders that occur under the influence of long-term experience of aggression. Similarity of symptomatics of movement disturbances in mice and in humans with some neurological diseases is discussed.

[Secretion of proteolytic enzymes by three phytopathogenic microorganisms].

Serine proteinases from three phytopathogenic microorganisms that belong to different fungal families and cause diseases in potatoes were studied and characterized. The oomycete Phytophthora infestans (Mont.) de Bary and the fungi Rhizoctonia solani and Fusarium culmorum were shown to secrete serine proteinases. An analysis of the substrate specificity of these enzymes and their sensitivity to synthetic and protein inhibitors allowed us to refer them to trypsin- and subtilisin-like proteinases. The correlation between the trypsin- and subtilisin-like proteinases depended on the composition of the culture medium, particularly on the form of the nitrogen source. A phylogenetic analysis was carried out. In contrast to basidiomycetes R. solani, ascomycetes F. culmorum and oomycetes P. infestans produced a similar set of exoproteinases, although they had more distant phylogenetic positions. This indicated that the secretion of serine proteinases by various phytopathogenic microorganisms also depended on their phylogenetic position. These results allowed us to suggest that exoproteinases from phytopathogenic fungi play a different role in pathogenesis. They may promote the adaptation of fungi if the range of hosts is enlarged. On the other hand, they may play an important role in the survival of microorganisms in hostile environements outside their hosts.

[Pro-aggressive effect of diazepam in male mice with repeated experience of aggression].

Previous studies have reported that repeated experience of aggression is attended with the development of increased anxiety in male mice. The paper aimed to investigate effect of anxiolytic, diazepam, on the level of anxiety and aggression in these animals. The drug was chronically administrated for two weeks at the process of aggression experience acquisition. It was shown that diazepam decreased anxiety but didn't influence aggression level assessed by total time of attacks. However, diazepam decreased demonstration of aggressive grooming in part of aggressive males. Group of diazepam-treated aggressive males which displayed aggressive grooming didn't differ in level of anxiety and aggression in saline-treated male mice. Diazepam had anxiolytic and pro-aggressive effects in male mice without demonstrating aggressive grooming. Thus, we can conclude that anxiolytic effect of diazepam is accompanied with increased aggression as side effect in some male mice which have repeated experience of aggression.

[Effects of diazepam on mixed anxiety/depression state in male mice].

Chronic social defeat stress in daily agonistic interactions leads to the development of mixed anxiety/depression state in male mice. This paper aimed to study the effects of chronic diazepam treatment on the psychoemotional state of these animals. Diazepam (0.5 mg/kg, i/p, Polfa Tarchomin S. A.) or saline was chronically injected into male mice for two weeks on the background of continuing agonistic interactions (preventive treatment) or into male mice with mixed anxiety/depression state after stopping of social confrontations (therapeutic treatment). Then, the animals were studied in the partition, plus-maze and Porsolt' tests, estimating the levels of communicativeness, anxiety and depressiveness, respectively. Preventive diazepam treatment had a weak protective anxiolytic and pro-depressive effect. The therapeutic diazepam treatment didn't influence on the anxiety and depression-like state. Chronic diazepam was ineffective for the treatment of the mixed anxiety/depression state in male mice. Different effects ofdiazepam on anxiety and depression-like states under preventive treatment confirmed our conclusion shown earlier about the independent development of these pathologies at least in our experimental paradigm.

[Attenuating effect of sucrose solution intake on increase in aggression produced by fighting deprivation in male mice with repeated experience of victories].

It was found earlier that winners (male mice with experience 20 daily victories in aggressive agonistic encounters) showed enhanced aggression after a 2-week no-fight period, compared to their respective levels of aggressive behavior before the fighting deprivation. In this work we showed that sucrose solution intake in the deprivation period attenuated the level of post-deprivation aggression and decreased anxiety in such animals. Negative correlations were found between sucrose intake and aggression level. Putative mechanisms of attenuating sucrose effect on aggressive behavior are discussed.

[The influence of cultural medium composition on the proteolytic enzyme secretion of fungus Rhizoctonia solani].

It was shown that change of medium growth composition of photopathogenic fungus Rhizoctonia solani Kühn, especially accessible sources of nutrition, leads to change of both quantity of produced proteinases and their action specificity. The mineral source of nitrogen suppressed the fungus proteinase secretion on cultivation medium containing potato thermostable proteins but an organic source of nitrogen accelerated mycelium growth and increased proteinase secretion. On the basis of an analysis of a fungus extracellular proteinase substrate-specificity, it is established that the presence of thermostable proteins of a potato in the cultural liquid induces the secretion of trypsin-like proteinases mainly, and the addition of yeast extract to this growth medium induces the secretion of subtilisin-like ones, thus suppressing the trypsin-like enzymes production. This fact can indicate that mycelium of fungus R. solani loses pathogenic properties and becomes saprophytes when the growth medium was enriched by an organic source of nitrogen.

[Effect of sodium valproate on aggressive behavior of male mice with various aggression experience].

Sector of Social Behavior Neurogenetics, Institute of Cytology and Genetics, Siberian Branch, Effects of sodium valproate on the aggressive behavior of male mice with 2- and 20-day positive fighting experience have been studied. It is established that valproate administered in a singe dose of 100 mg/kg has no effect on the behavior of male mice with a 2-day experience of aggression. The treatment of mice with 300 mg/kg of valproate significantly decreased the level of aggressive motivation and the percentage of animals demonstrating attacks and threats. In male mice with a 20-day experience of aggression, valproate decreased the time of hostile behavior in a dose-dependent manner. Valproate in a single dose of 300 mg/kg significantly decreased the level of aggressive motivation, but also produced a toxic effect, whereby 73% of aggressive males demonstrated long-term immobility and 45% exhibited movement abnormalities (falls) upon the treatment. It is suggested that changes in the brain neurochemical activity, which are caused by a prolonged experience of aggression, modify the effects of sodium valproate.

[Decrease in sucrose solution consumption by CBA/Lac male mice under chronic social stress].

The influence of repeated experience of social defeats in daily agonistic interactions on voluntary consumption of 1% sucrose solution supplemented with vanillin (0.2%) was studied in male mice of CBA/Lac strain with genetic predisposition to catalepsy as compared to depression-predisposed C57BL/6J mice. Intact mice of both strains prefered sucrose solution to water under conditions of two-bottle free choice. Sucrose solution intake was shown to decrease in losers of both strains exposed to social confrontations as compared to controls. It was suggested that the high level of anxiety revealed in mice of both strains can be the determining factor of the decrease in sucrose solution consumption under conditions of chronic social stress.

[Effect of positive and negative social experiences on sucrose solution intake by male mice].

Hedonic reactions to various rewards play a key role in various forms of motivated behavior. The influence of repeated experience of social victories or defeats in daily agonistic interactions between male mice on voluntary consumption of 1% sucrose solution supplemented with vanillin (0.2%) was studied. Intake of sucrose solution was shown to be decreased in the winners and losers exposed to social confrontations as compared with the controls. Three days of deprivation restored the intake of sucrose solution to the control level in the winners and failed to restore the baseline intake in the losers. The results imply that similar reaction of animals to a hedonic non-drug reinforcer may have different motivational origin depending on positive or negative social experience.

[Effects of ethanol on metastasis of Lewis lung carcinoma in male mice with different social states].

The aim of this work was to study the effect of ethanol on experimental metastasis of Lewis lung carcinoma in male mice in positive or negative emotional states. Sensory contact model was used for generating animals with repeated experience of social victories or defeats. Tumor cells were injected into the tail vein after 20 days of agonistic interactions, and the number of metastases in the lung was calculated 16 days later. Group-housed mice were used as the controls. Mice of all experimental groups were chronically treated with ethanol (20%, 2 ml/kg of weight, i.p.) and saline during 7 days starting with the day of tumor cells injections. The experimental metastasis was shown to develop differently in mice with opposing social experience: saline-treated winners had significantly less metastases in the lung than the saline-treated losers. Chronic ethanol injections decreased the number of metastases in the losers, increased it in the winners and did not affect the controls. The results obtained indicate that effects if ethanol on Lewis lung carcinoma metastasis depend on psychoemotional status in male mice.

[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.

[Influence of experimental context on the development of anhedonia in male mice exposed to chronic social stress].

Consumption of 1% sucrose solution supplemented with 0.2% vanillin was studied in two experimental contexts in male mice living under chronic social stress induced by daily experience of defeats in agonistic interactions and leading to development of depression. In the first experiment, vanillin sucrose solution was made available as an option along with water during 10 days for mice living in group home cages. Then the mice were subjected to repeated social defeat stress and during exposure to stress they were provided with both vanillin sucrose solution and water using a free two-bottle choice paradigm. In the other experiment, vanillin sucrose solution was first offered to mice after 8 days of exposure to social defeat stress. Males familiar with vanillin sucrose solution showed vanillin sucrose preference while experiencing defeat stress: consumption of vanillin sucrose solution was about 70% of total liquid consumption. However, the consumption of vanillin sucrose solution per gram of body weight in mice exposed to social stress during 20 days was significantly lower than in control males. In the second experiment, males after 8 days of social defeat stress were found to consume significantly less vanillin sucrose solution as compared to control males. On average, during two weeks of measurements, vanillin sucrose solution intake was less than 20% of total liquid consumption in males. Consumption per gram of body weight also appeared to be significantly lower than in control group. The influence of experimental context on the development of anhedonia measured as a reduction of sucrose solution intake by chronically stressed male mice is discussed.

[Interaction between proteinases secreted by the fungal plant pathogen Rhizoctonia solani and natural proteinase inhibitors produced by plants].

The fungal plant pathogen Rhizoctonia solani Kuhn. grown in a medium containing thermostable potato tuber proteins produced proteinases active at moderately alkaline pH values. Electrophoretic analysis in polyacrylamide gel with SDS and copolymerized gelatin showed that the extracellular proteinase complex contained four components that differed in molecular weight. Studies on the action of the exoenzymes on various synthetic substrates indicated that the culture liquid of R. solani contained mainly trypsin-like proteinases. The exoproteinase activity was virtually completely suppressed by trypsin inhibitor proteins isolated from potato tubers and seeds of various legume species. The results suggest that the extracellular proteinases produced by R. solani play a significant role in attacking plant tissue, and natural inhibitors contribute to the protection of Solanaceae and Leguminosae from this fungal pathogen.

[Extracellular proteinases from the phytopathogenic fungus Fusarium culmorum].

The growth of Fusarium culmorum fungus on a medium containing thermostable proteins from potato tubers was accompanied by the production of proteinases, exhibiting activity over a broad pH range (from 6.0-10.0). When studied by SDS-PAGE in the presence of beta-mercaptoethanol, extracellular proteinases were represented by at least five species with a molecular weight of 30-60 kDa. Inhibitor analysis and studies of enzyme activities with synthetic substrates demonstrated that the culture liquid of Fusarium culmorum contained serine proteinases of various classes. The amount of subtilisin-like proteinases was the highest. A near-complete inhibition of the enzymes was caused by proteinaceous proteinase inhibitors from potato tubers. These data suggest that proteinases of the phytopathogen Fusarium culmorum serve as a metabolic target for natural inhibitors of potato proteinases.

[Development of anhedonia under negative experience of social confrontations in male mice].

Possible development of anhedonia in male mice under chronic stress produced by social confrontations was investigated. Cheese, instead of traditional sucrose solution, was used as a positive reinforcement. It has been shown that the controls, the winners with repeated experience of aggression accompanied by victories and the losers with repeated experience of social defeats, irrespective of their social status, preferred to eat cheese, but not pellets, under the free choice conditions--80% of total food. After three days of cheese deprivation, the least food motivation and the least level of cheese consumption were observed in the losers as compared with the controls and winners. Influence of social stress as well as negative psychoemotional state produced by social defeats, on development of anhedonia as a symptom of major depression, is discussed.

[Impaired social recognition in male mice with repeated experience of aggression].

Social recognition is crucial for many aspects of animal behavior in stabilized population. Preliminary data proposed impairment of social recognition in male mice with long experience of aggression. To check this hypothesis, experiments with male mice with different aggressive experience (during 2 and 20 days) were performed. Two types of losers were used as partners: losers with active defense reactions and losers displaying submissive postures. The enhanced aggressive motivation was found in both groups of aggressors. Mice with short aggressive experience demonstrated intensive attacks toward the active losers and decreased aggression directed to submissive losers. Mice with long aggressive experience did not change their behavior depending on a type of the partner and displayed a high level of aggression as a result of dominant aggressive motivation and impaired social recognition.

[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.

[Changes in the expression of monoaminergic genes under the influence of repeated experience of agonistic interactions: from behavior to gene]. / Izmeneie ékspressii monoaminergicheskikh genov pod vliianiem povtornogo opyta agonisticheskikh vzaimodeistvii: ot povedeniia k genu.

The role of genetic and environmental factors as well as brain neurochemistry in regulating aggressive and submissive behaviors in animals are considered. We present a review of data on changes in brain monoaminergic activity (synthesis, catabolism, receptors) and on the expression of monoaminergetic genes under repeated daily agonistic confrontations in male mice. A repeated experience of aggression was shown to result in the total activation of the dopaminergic system and the inhibition of the serotonergic one. This was accompanied by a decrease in the mRNA level of the catechol-O-methyltransferase gene in the midbrain and an increase of the mRNA level of the dopamine transporter and tyrosine hydroxylase genes in the ventral tegmental area of aggressive male mice. Repeated experience of social defeats produced dynamic changes in the serotonergic system of some brain areas and an increase of the mRNA level of the serotonin transporter and monoamine oxidase A genes in the midbrain raphe nuclei. Theoretical and methodological possibilities of the proposed ethological approach for studying molecular mechanisms of agonistic behavior are discussed in the context of the fundamental problem of investigating the ways of regulation from behavior to gene.