Correlations of Expression Levels of Lung Cancer Marker Gene Eno2 and Genes of Carcinogenesis and Apoptosis in the Hypothalamus of Mice with Depression-Like Behavior.

We experimentally demonstrated that chronic social stress during the development of a depression-like state enhances lung metastasis and modifies the expression of many carcinogenesis- and apoptosis-related genes in the hypothalamus of mice, including genes involved in lung cancer pathogenesis in humans. Analysis of the expression of genes encoding the major clinical markers of lung cancer in the hypothalamus of mice with depression-like behavior revealed increased expression of the Eno2 gene encoding neuron-specific enolase, a blood marker of lung cancer progression in humans. It was shown that the expression of this gene in the hypothalamus correlated with the expression of many carcinogenesis- and apoptosis-related genes. The discovered phenomenon may have a fundamental significance and requires further studies.

[Serotonergic genes in the development of anxiety/depression-like state and pathology of aggressive behavior in male mice: RNA-seq data].

In course of daily agonistic interactions, mice tend to stratify into those with chronic social defeats and those that repeatedly display aggression, which lead to the development of mixed anxiety/depression-like state and the pathology of aggressive behavior, respectively. Using the data of whole transcriptome analysis (RNA-seq), the changes in the expression of serotonergic genes involved in the synthesis, inactivation, and reception of serotonin, as well as of the Creb1 (transcription factor) gene and the Bdnf (brain-derived neurotrophic factor) gene were detected in the striatum (STR), ventral tegmental area (VTA), midbrain raphe nuclei (MRN), hypothalamus (HYP), and hippocampus (HIP) of defeated and aggressive male mice. In mice of both groups, the Tph2, Ddc, Slc6a4, Htr2a, Htr3a, Htr5b, Slc18a2, and Bdnf genes were downregulated in the MRN and the Tph2, Ddc, and Slc6a4 genes were upregulated in the VTA. These changes were more significant in defeated mice. The Htr5b gene has first been shown to be involved in mechanisms of depression and pathology of aggressive behavior. In the defeated mice, the expression levels of the Htr4 and Aldh1b1 genes were increased in the MRN, and expression levels of the Maob, Htr4, Htr1a, and Slc18a2 genes were increased in the VTA, while the expression level of the Htr3a gene was decreased. In the HYP of aggressive mice the Maoa, Htr2a, Htr2c, and Creb1 genes were downregulated and the Htr6 gene was upregulated. In the defeated mice, the Maoa and Creb1 genes were downregulated and the Htr6 and Aldh1b1 genes were upregulated in the HYP. In the STR, the Htr1a gene was downregulated and the Htr7 and Bdnf genes were upregulated. The Htr1b gene was upregulated in the HIP. The coexpression of dopaminergic and serotonergic genes in the MRN and VTA in the control of pathological behaviors is discussed. Thus, the complex pattern of differential expression of serotonergic genes in brain regions developing under repeated agonistic interactions in mice in dependence on behavioral pathology have been observed.

[Altered Expression of Neurotransmitters Systems' Genes in the Ventral Tegmental Area of Depressive Male Mice: Data of RNA-Seq].

Chronic social defeat stress (CSDS) leads to the development of mixed anxiety/depression-like state in male mice similar to those in humans. It has been shown that, under CSDS, the adult brain undergoes changes in the functioning neurotransmitter systems in different brain regions. In this experiment we are focused on the analysis of expression of genes encoding proteins related with the metabolism and receptors of serotonin, catecholamines, GABA and glutamate in the ventral teg- mental area which is important for regulation of motivations, emotions and is involved into mech- anisms of affective disorders. Mixed anxiety/depression-like state was generated in male mice by exposure to CSDS during 20 days. The collected samples of the ventral tegmental area were se-- quenced at JSC Genoanalytica,(http://genoanalytica.ru/, Moscow, Russia).'We found that genes, related with serotonin (Tph2, Maob, SIc6a4, Htr4, Htr1a) were upregulated but expression of Htr3a gene was downregulated in the ventral tegmental area of depressive mice in comparison with the control. Besides, upregulation of dopaminergic Th, Ddc, Slc6a3, Sic18a2, Drd2, and Maob genes was found while noradrenergic Dbh, Slc6a2, Adra2c, and Adra2a genes were downregulated. Ex- pression of GABAergic Gabral, Gabra2, Gabrg2, Gabrg], Gabrq, Gad], and Gad genes as well as glutamatergic Grial, Gria2, Grik2, Grm2, Grm5, and Slc 7a8 genes were increased under CSDS. Development of mixed anxiety/depression-like state under CSDS in male mice is accompanied by increased expression of genes coding the proteins participating in the metabolism and receptions of serotonergic, dopaminergic, glutamatergic and GABAergic systems. Expression of genes coding the adrenergic reception is decreased. It is supposed that Drd2 H Htr3a genes may play the key role in the synchronization of other genes of neurotransmitter systems.

[Relationship of Anxiety and Depression in the Development of Mixed Anxiety/Depression Disorder. An Experimental Study of Comorbidity Mechanisms (Review)].

As clinical practice and experimental studies show, symptoms of depression and anxiety often accompany each other. It is well known that combination of anxiety and depression in patients is treated more slowly, requires large doses of drugs, increases the likelihood of suicide and often leads to relapse. Furthermore, antidepressants and anxiolytics exert its therapeutic effect in limited cases even in monopolar anxiety or depression state. In this review of literature and our own data the relationship of anxiety and depression is analyzed. It has been shown with using the model of mixed anxiety/depression disorder caused by chronic social defeat stress, that the anxiety and depression are changed under the influence of psychotropic drugs independently.

[Changes in the Expression of Dopaminergic Genes in Brain Structures of Male Mice Exposed to Chronic Social Defeat Stress: An RNA-seq Study].

Whole-transcriptome analysis (RNA-seq) has been used to analyze changes in the expression of dopaminergic genes that encode proteins involved in the synthesis, inactivation, and neurotransmission of dopamine in the striatum, ventral tegmental area, raphe nuclei of the midbrain, hypothalamus, and hippocampus of male mice subjected to chronic social defeat. The expression of Th, Ddc, and Slc6A3 (Dat1) was upregulated, while that of Ppp1r1b and Sncg was downregulated in the ventral tegmental area; the expression of Th, Ddc, Drd2, and Sncg was downregulated in the raphe nuclei of midbrain; the expression of Th, Aldh2, and Ppp1r1b was upregulated, while that of Маоа was downregulated in the hypothalamus; Drd1 and Snca expression was downregulated and that of Sncb was upregulated in the striatum, and Sncb expression was upregulated in the hippocampus. There were no statistically significant changes in the expression of Comt, Maob, Drd3, Drd4, or Drd5 in the brain areas analyzed in stressed male mice (compared to control animals). Thus, the number of differentially expressed dopaminergic genes and the direction of expression changes in male mice experiencing chronic stress are specific to regions of the brain.

[Alteration of Social Behaviors in Male Mice of CBA/Lac Strain under Agonistic Interactions].

Ability of people to communicate with each other is a necessary component of social behavior and normal development of individuals living in community. A pronounced impairment in communication may be the result of autism which is characterized by impaired socialization, low communication and restricted and/or repetitive behaviors. It is hypothesized that genes or rare mutations play a key role in the development of autism. However a multifold increase of the cases with autistic spectrum symptoms over the last years cannot be attributed exclusively to genetic mutations or heredity. Environmental contribution to the development of autistic symptoms has to be considered. The paper aimed to analyze the social behaviors of CBA/Lac mice with repeated experience of aggression or social defeats in daily agonistic interactions with accent on searches of associations with autistic symptoms in comparison with previously studied C57BL/6J animals. It has been shown that male mice of both strains with alternative social behaviors demonstrated the changes in social behaviors; however the expression of some form of behaviors was different. The data obtained to assert that long-term hostile social environment lead to development of disturbances in social behaviors, accompanying by autistic-like symptoms.

[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.

[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.

Gender-related characteristics of responding to prolonged psychoemotional stress in mice.

The behavior of male and female C57BL/6J mice was studied after prolonged psychoemotional stress imposed by enforced cohabitation with an aggressive male on the other side of a partition in the cage and daily witnessing of 10-minute confrontations between the aggressor and another male placed with it. The elevated plus maze test demonstrated marked anxiety in mice of both genders after one month of psychoemotional stress. However, only females, but not males, showed an increase in the duration of passive swimming in the Porsolt test, along with some reduction in communicativeness in the partition test. Thus, these studies showed a more marked reaction to prolonged pscyhoemotional stress in females than in males.

[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.

[Mouse gender-related behavioral responses to long-lasting psychoemotional influence].

Behavior of male and female inbred mice of C57BL/6J strain was studied after long-lasting psychoemotional influence consisting of forced living with aggressive male separated with a perforated transparent partition in the same cage, and daily presence of males and female during 10-min intermale confrontations behind a partition caused by introducing intact mouse to an aggressive male. In a month, the increased level of anxiety in mice of both genders was revealed in the elevated plus-maze test. However, only females showed a longer time of passive swimming in the Porsolt's test. Under these conditions, females demonstrated some decrease of communication in the partition test. Accordingly, a more expressed behavior response was revealed in females in comparison with males on long-lasting psychoemotional influence.

Behavioral effect of terahertz waves in male mice.

We studied the effect of terahertz waves (3.6 THz, 81.5 micro, 15 mW) on the behavior of mice. The mice perceived terahertz waves even after short-term exposure (15 min). The effect of terahertz waves was maximum in direct contact of the mice with the laser. Increased anxiety of experimental animals was observed on the next day after 30-min irradiation.

[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.

An experimental approach for the study of psychotropic drug effects under simulated clinical conditions.

The sensory contact model can induce various different psychopathological states in male mice (anxious depression, catalepsy, social withdrawal, pathological aggression, cognition disturbances, anhedonia, alcoholism etc.). Additionally, this model facilitates the screening of drugs for therapeutic properties, preventive properties and efficiency under simulated clinical conditions. This approach can reveal the action of drugs at different stages of disease development. It is proposed that this pharmacological approach can be applied for the screening of various novel psychotropic drugs.

Effects of single episodes of severe stress on the behavior of male and female CBA/Lac and C57BL/6J mice.

Experiments were performed to compare the behavior of male and female mice of the inbred strains CBA/Lac and C57BL/6J in the open field test after single episodes of severe stress imposed by forced swimming. Testing was performed 2 h (first test) and one day (second test) after stress. Control animals were intact males and females of these strains, and were also tested in the open field on two sequential days. Both male and female CBA/Lac mice showed increases in the latent period of excursions from the center of the field 2 h after stress. This change persisted to the second test in female CBA/Lac mice. In female C57BL/6J mice, there were changes in four of seven behavioral measures 2 h after stress, though at one day their behavior was as in control individuals. Stress had virtually no effect in males of this strain, only increasing the number of grooming acts in the first test. In addition, detailed analysis of the effects of repeat testing in control and stressed individuals of these mouse strains also revealed interstrain and gender-related differences in the effects of stress. The possible existence of increased basal (trait) and situational (state) anxiety in female C57BL/6J and CBA/Lac mice respectively is discussed.

[Effects of acute and chronic introduction of fluoxetine on anxiety-depressive condition of male and female mice].

The effects of acute and chronic fluoxetine treatment in intact and anxiety-depressive male and female inbred mice of the C57BL/6J strain were studied. The gender differences in the behaviour of mice in the tests estimating anxiety, locomotion and exploration activity, communication, and depressive-like state after fluoxetine injection were established. The dependence of fluoxetine treatment on normal or pathological state in mice was discovered. It was concluded that use of the animals in pathological condition and chronic (but nor acute) fluoxetine treatment are represented as the most correct estimative means of antidepressant efficiency.

[Effect of a single severe stress on behaviour of males and females in the mouse inbred strains CBA/Lac and C57BL/6J].

The effect of single severe stress in the form of forced swimming on the behavior of males and females in the mouse inbred strains CBA/Lac and C57BL/6J were examined in the open field test. Measurements were carried out within two hours after the stress exposure (Trial 1) and repeated 2 hours thereafter (Trial 2). Intact males and females of the both mouse strains which tested in the open field twice too were used as control. An increased latency was found until first escape from the center both in males and females of the CBA/Lac strain within two hours after the end of forced swimming. This parameter was still high in females in the Trial2. Four out of seven behavior parameters were changed in females of the C57BL/6J strain two hours after the stress exposure, but their behavior was similar to control in the Trial 2. The males of the C57BL/6J strain demonstrated the least changed behavior in the open field test after the stress exposure with the exception of increased number of grooming in the Trial 1. Further on, a detailed analysis of repeated testing in the open field within intact and stressed mice of both strains was performed. This comparison allowed revealing hereditary and gender peculiarities in the mouse behavior after single severe stress exposure. The results are discussed in respect to the possible genetically inherent increased traitanxiety in females of C57BL/6J strain and the state of anxiety in females of CBA/Lac strain.

[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.

The effects of fluoxetine and its complexes with glycerrhizic acid on behavior in rats and brain monoamine levels.

The effects of the serotonin reuptake inhibitor fluoxetine (FL) and its complexes with glycyrrhizic acid (GA) in molar ratios of 1:1 (FLG-1) and 4:1 (FLG-4) on the behavior of adult rats were studied in an elevated cross maze, with measurement of brain monoamine and monamine metabolite levels. Agents were given via the intragastric route using a cannula at a dose of 25 mg/kg 1 h before testing. FL increased anxiety in the rats and decreased their movement activity; FLG-1 and FLG-4 had no effect on behavior. None of the agents affected brain serotonin content, though all decreased the levels of its metabolite 5-hydroxyindoleacetic acid in the hypothalamus, FLG-4 also decreasing this in the cortex. Noradrenaline levels in the hypothalamus were increased after FLG-1 and FLG-4. In the striatum, FL increased the levels of dopamine and its metabolite dihydroxyphenylacetic acid but had no effect on the level of transmitter catabolism. Unlike FL, FLG-1 activated dopamine metabolism in the striatum. Overall, use of FL complexed with GA significantly modified its behavioral effects, which appears to be associated with the effects of FL and its complexes on the function of the monoaminergic systems involved in controlling behavior.