Effect of the D1-receptor antagonist SCH-23390 on the individual and aggressive behavior in male mice with various aggression experience

It has been shown that dopaminergic systems are involved in mechanisms of aggressive behavior. Effects of SCH 23390 (dopamine Di receptors antagonist. 0-1 mg/kg, i/p, 30 min) on aggressive and individual behaviors were studied in male C57BL/6J mice with different experience of aggression. SCH 23390 reduced aggressive attacks in animals without preliminary experience of aggression. However total time of hostile behavior (sum of the total time of attacks, aggressive grooming and diggings) didn't changed. No significant effects on behaviors were found in mice with long (20 days) repeated experience of aggression. It was supposed that long aggressive experience produces pharmacological desensitization of Di receptors as a result of enhanced dopaminergic activity shown earlier in aggressive animals.     

Androgen levels and components of aggressive behavior in men

Serum concentrations of testosterone (Tser), 5 alpha-dihydrotestosterone (DHT), and free testosterone (Tsal) in saliva were determined in 117 healthy young men between the ages of 20 and 30. A battery of standardized tests and projective techniques were administered simultaneously in order to measure various components of aggression, including sexual aggressiveness. All three androgens show reliable positive correlations with self-ratings of spontaneous aggression. Dominance exhibits a positive, statistically significant correlation to Tser and to DHT. In addition, DHT is negatively related to the scale restraint of aggression. These results support previous findings about Tser and point to the importance of other androgens--especially DHT--for this aspect of endocrine-affect relationships. Interest in sexual aggression yielded no significant results for Tser and DHT (Tsal shows a low positive correlation). The ratio DHT/Tser, however, correlates significantly with this component of aggression.     

Influence of aggressive computer games on the brain cortex activity level in adolescents

Dynamic changes in the activities of different areas of the brain cortex were studied in order to determine cortical structures responsible for playing aggressive computer games, with the degree of initial aggression of the adolescent subjects taken into account. Changes in anxiety and aggression produced by aggressive computer games were found to depend on the initial level of aggression of the subjects. In adolescents with a high baseline level of aggression, the amplitude of the N200 component increased in the frontal and decreased in the temporal areas of the cortex, whereas, in adolescents with a low baseline aggression level, N200 decreased in the frontal and increased in the temporal cortical areas.     

Changes in levels of amino acid acceptors in tRNA from Escherichia coli grown under various conditions

Active enzyme sedimentation of five asparaginase and glutaminase-asparaginase enzymes with antitumor activity was studied. The catalytically active species of each enzyme appeared to have a molecular weight greater than 100,000 g/mole. Gel filtration and disc gel electrophoresis confirmed the absence of catalytically active smaller species.     

Changes in the correlations of the different indices of the entire behavior of dogs under the influence of seduxen

During chronic use of seduxen various changes of correlation connections between different parameters of general behaviour are revealed in dogs. The character and degree of expressiveness of these changes depend on the drug dose and typological characteristics of animals. The most general and significant manifestation of favourable effect of the drug action on animals behaviour is an increase of the number of "strong" correlation connections (correlation coefficient is more than 0.7) of the parameters of various components of conditioned activity, reflecting the state of inner inhibition processes, and to the parameters of vegetative provision of conditioned reactions. The character of reconstructions of correlation connections between different conditioned, vegetative, neurotransmitter and general behaviour parameters allows to judge of the direction of pharmacological influence on separate functional systems and the behaviour as a whole.     

捕食和食物交互作用条件下根田鼠季节性波动种群攻击水平及其行为多态性分析

在捕食和附加食物交互作用条件下,以恐吓、进攻、追逐、争斗及回避5类行为为变量,以恐吓、进攻、追逐计数之和的平均值作为攻击水平,测定根田鼠种群不同波动时期成体的攻击水平.发现根田鼠的攻击性与种群波动时期之间,存在明显的关联.统计分析结果表明,在种群3个波动时期,4种处理种群两性攻击型个体比例差异显著.除预防捕食者无附加食物（-P,-F）种群的雌体外,其它处理种群增长期和高峰期雌性和雄性攻击型个体的比例高于其衰减期.其中,预防捕食者附加食物（-P,＋F）种群、-P,-F种群及未预防捕食者附加食物（＋P,＋F）种群,雄性攻击型个体的比例均为增长期＞高峰期＞衰减期;在未预防捕食者无附加食物（＋P,-F）种群,雄性攻击型个体比例为高峰期＞增长期＞衰减期.各处理种群雌性攻击型个体比例的格局与雄体的不同.其中,-P,＋F种群及＋P,＋F种群为增长期＞高峰期＞衰减期,＋P,-F种群为高峰期＞增长期＞衰减期,而-P,-F种群攻击型个体比例为高峰期＞衰减期＞增长期.虽不同处理种群雌体及雄体的5类行为变量与种群密度的相关性不一致,而具有明显攻击性的恐吓、进攻及争斗3类行为则分别与种群密度呈显著或极显著的线性正相关关系,其结果与Chitty多态行为假设预测的一致;验证了所提出的特定假设：种群外部因子捕食和食物交互效应介导的攻击行为选择,是引起田鼠类种群季节性波动的主要内部因子.     

Self-reported symptoms of depressed mood, trait anxiety and aggressive behavior in post-pubertal adolescents: Associations with diurnal cortisol profiles

The association between self-reported symptoms and diurnal cortisol profiles was studied in post-puberty adolescents (29 boys and 29 girls, M_age = 15.06 years). The adolescents completed the Children's Depression Inventory, State Trait Anxiety Inventory, and an Aggressive behavior scale. The diurnal cortisol profile was derived from three saliva samples, collected at awakening, noon and evening on a week-end day. Univariate repeated measurement regressions revealed that depressed mood and trait anxiety were strongly and aggressive behavior was weakly related to the diurnal cortisol profile: greater emotional distress was associated with flatter diurnal cortisol profiles. Multivariate analysis, however, revealed that only trait anxiety made an independent contribution. Further analyses suggested that trait anxiety was related to elevated evening cortisol rather than to decreased awakening cortisol and that from a trait anxiety score of 38 onwards, high anxious adolescents show clearly higher evening cortisol than low anxious adolescents. These data suggest that anxiety disorder co-morbidity might explain some of the differences in HPA-axis function among depressed patients.     

Colour and levels of aggression in the midas cichlid

Previous work established that gold morphs of the Midas cichlid (Cichlasoma citrinellum) dominate normal ones of about the same size. Left unresolved, however, was whether the gold morphs dominate because they are inherently more aggressive or because the gold colour inhibits aggression. The issue was clarified here by comparing levels of aggression within groups of golds only, normals only, and golds plus normals. At first the groups of golds were the least aggressive. But 2 days later the levels of aggression in the other groups fell to about that of the golds. We conclude therefore that the gold colour inhibits attack, but that this effect is only discernible in groups when they are establishing inter-individual relationships disappearing when the groups stabilize. We suggest that gold coloration inhibits attacking by stimulating fear responses.