Anti-estrogen inhibition of testosterone-stimulated aggression in mice

Testosterone-stimulated intermale aggression in castrated mice can be reversibly inhibited by anti-estrogen administration suggesting that estrogen formation and actions in the brain may be required for testosterone's behavioral actions.     

Effects of testosterone-stimulated glycogen synthesis in the mouse salivary glands and 5-fluorouracyl inhibition

Resumen En el presente trabajo se estudia la accion de testosterona sobre el metabolismo del glucogeno. Se observa que despues de la inyeccion de la hormona aumenta el glucogeno y que y este es inhibido por 5-FU. Se sugiere que la sintesis de glucogeno necesite una estimulacion previa de nucleotidos de RNA y de proteinas.

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This work was supported by a grant from the Consejo Nacional de Investigaciones Cientifica y Tecnica, Argentina.     

Circling behavior in mice and rats: possible relationship to isolation-induced aggression

The relationship between circling behavior (rotation), isolation, and aggression was investigated in normal male mice and rats. Initially the animals were tested for spontaneous nocturnal rotation, then conspecific aggression and muricidal behavior was observed for mice and rats respectively. Subsequently, animals were paired on the basis of net nocturnal rotations and either group-housed or individually housed. Four weeks later all animals were retested for the same behaviors. Spontaneous nocturnal rotation increased significantly for the isolated mice but not for the group-housed animals. Moreover, 9 of the 10 isolates became aggressive and their net rotations were significantly and positively correlated with the number of biting attacks. None of the group-housed mice became aggressive. Rats, on other hand, showed a decrease in rotation and a relationship between rotation and muricidal behavior was not evident. The possible relationship between circling behavior, aggression, and territoriality is discussed.     

Circling behavior in mice and rats: possible relationship to isolation-induced aggression

Summary The relationship between circling behavior (rotation), isolation, and aggression was investigated in normal male mice and rats. Initially the animals were tested for spontaneous nocturnal rotation, then conspecific aggression and muricidal behavior was observed for mice and rats respectively. Subsequently, animals were paired on the basis of net nocturnal rotations and either group-housed or individually housed. Four weeks later all animals were retested for the same behaviors. Spontaneous nocturnal rotation increased significantly for the isolated mice but not for the group-housed animals. Moreover, 9 of the 10 isolates became aggressive and their net rotations were significantly and positively correlated with the number of biting attacks. None of the group-housed mice became aggressive. Rats, on other hand, showed a decrease in rotation and a relationship between rotation and muricidal behavior was not evident. The possible relationship between circling behavior, aggression, and territoriality is discussed.     

Alpha-fetoprotein in tumor-bearing mice assayed by particle agglutination inhibition

Summary Serum alpha-fetoprotein (AFP) in hepatoma BW7756-bearing mice was measured by a new particle agglutination inhibition test employing AFP adsorbed to charcoal particles. The AFP levels and tumor weights showed nearly parallel increases to means of 2633 g/ml and 5.2 g, respectively, 28 days after implantation. *** DIRECT SUPPORT *** A2025089 00011     

Alpha-fetoprotein in tumor-bearing mice assayed by particle agglutination inhibition.

Serum alpha-fetoprotein (AFP) in hepatoma BW7756-bearing mice was measured by a new particle agglutination inhibition test employing AFP adsorbed to charcoal particles. The AFP levels and tumor weights showed nearly parallel increases to means of 2633 microgram/ml and 5.2 g, respectively, 28 days after implantation.     

Circling behavior induced by phencyclidine in mice and its inhibition by naloxone

Summary Phencyclidine (PCP), when given to mice, induces general hyperactivity and rapid circling, similar to that caused by morphine. These effects are partially antagonized by naloxone.Acknowledgment. We are grateful to Professor A. Kalir for the donation of PCP. Correspondence and reprint requests should be addressed to A. M. Korczyn.     

Circling behavior induced by phencyclidine in mice and its inhibition by naloxone

Phencyclidine (PCP), when given to mice, induces general hyperactivity and rapid circling, similar to that caused by morphine. These effects are partially antagonized by naloxone.     

Increased aggression in rats after withdrawal of long term used oxazepam

Summary The withdrawal of oxazepam (5 mg/kg i.p.) applied for 1 year in rats, increased shock-induced aggression of animals. This phenomenon is interpreted as a sign of abstinence and suggests that long-term treatment causes dependence to oxazepam in rats.Acknowledgment. Authors express their gratitude to Polfa, Warszawa, for the generous supply of oxazepam.     

The inhibition of antibody production in mice caused by the injection of specific antiserum on the first day of life

Résumé L'injection de l'antitoxine diphthérique aux souris nouvelles-nées inhibe chez elles la production des anticorps lorsqu'elles sont, à l'état de maturité, immunisées à l'aide d'un toxoïde diphthérique. Nous avons examiné l'influence de la dose d'antisérum administrée aux animaux nouveaux-nées au cours d'immunisation passive ainsi que l'influence de la voie d'injection sur le degré d'inhibition de l'immunogenèse.     

Effect of lithium on aggression,mania- and permselective membranes

Zusammenfassung Nachweis, dass Li⁺-Ionen den elektrischen Widersrand von permselektiven Membranen, welche Phosphatgruppen enthalten, stark erhöhen. Die beruhigende Wirkung der Li⁺-Ionen bei psychischen Störungen könnte damit zusammenhängen.     

Heritable variation for aggression as a reflection of individual coping strategies

Evidence is presented in rodents, that individual differences in aggression reflect heritable, fundamentally different, but equally valuablealternative strategies to cope with environmental demands. Generally, aggressive individuals show an active response to aversive situations. In a social setting, they react with flight or escape when defeated; in non-social situations, they react with active avoidance of controllable shocks and with sustained activity during an uncontrollable task. In contrast, non-aggressive individuals generally adopt a passive strategy. In social and non-social aversive situations, they react with immobility and withdrawal.A main aspect of these two alternative strategies is that individuals with an active strategy easily develop routines (intrinsically determined behaviour), and consequently do not react (properly) to minor changes in their environment, whereas in passively reacting animals it is just the other way around (extrinsically determined behaviour). It has become clear that active and passive behavioural strategies represent two different, but equivalent, coping styles. The coping style of the aggressive males is aimed at the removal of themselves from the source of stress or at removal of the stress source itself (i. e. active manipulation). Non-aggressive individuals seem to aim at the reduction of the emotional impact of the stress (i.e. passive confrontation). The success of both coping styles depends upon the variability or stability of the environment. The fact that aggressive males develop routines may contribute to a fast excution of their anticipatory responses, which is necessary for an effective manipulation of events. However, this is only of advantage in predictable (stable) situations, but is maladaptive (e.g. expressed by the development of stress pathologies) when the animal is confronted with the unexpected (variable situations). The flexible behaviour of non-aggressive individuals, depending strongly upon external stimuli, will be of advantage under changing conditions.Studies on wild house mice living under natural conditions show how active and passive coping functions in nature, and how the two types have been brought about by natural selection.