Effect of anosmia on the behavior of standard non-aggressive male mice opponents during agonistic encounters

This study assessed whether the differences observed in a previous experiment [Martinez M, Salvador A, Simon VM (1994): Aggressive Behavior 20:441–451] in the behavior of isolated male mice over several agonistic encounters in which they confronted either an “anosmic” or an “intact” non-aggressive “standard opponent” were due to the differences in the behavior of the opponents themselves. Ethologically-inspired analysis was used to assess the behavior of the opponents during the first agonistic encounter. Anosmic opponents spent less time in social investigation and defense and more time in immobility than intact ones. These results suggest that the differences in the behavior of the opponents could be one of the causes of the differences observed in the behavior of the aggressive males confronting them. However, more research is needed to study if other variables, such as the production of odors, are also affected by the state (deprived or intact) of the olfactory sense. These findings provide additional support for the view that the type of opponent used in studies on intermale aggression is of paramount importance.Aggr. Behav. 23:179–181, 1997.© 1997 Wiley-Liss, Inc.     

Behavioral profile of amisulpride in agonistic encounters between male mice

Amisulpride is a substituted benzamide derivative that acts as a selective dopamine D2/D3 receptor antagonist. Although the anti‐aggressive properties of neuroleptic drugs are well known, the effects of amisulpride on agonistic interactions have not been explored, and there are no studies comparing acute and subchronic effects of this compound on aggression in rodents. In this study, we examined the action of amisulpride (5–25 mg/kg, i.p), administered acutely or subchronically for 10 days, on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic "standard opponents" 30 min after drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. After acute treatment, amisulpride (5–20 mg/kg) exhibited an ethopharmacological profile characterized by a marked decrease of offensive behaviors (threat and attack) without an impairment of motor activity. By contrast, the anti‐aggressive action of the highest dose used (25 mg/kg) was accompanied by a weak increase of immobility. Body care was also significantly enhanced after treatment with the drug (20 and 25 mg/kg), emphasizing the involvement of dopaminergic receptors in this behavior. After subchronic treatment, no tolerance to amisulpride anti‐aggressive activity was observed. Overall, this behavioral profile is similar to that observed by other atypical neuroleptics. Aggr. Behav. 25:225–232, 1999. © 1999 Wiley‐Liss, Inc.     

An ethopharmacological assessment of agmatine's effects on agonistic encounters between male mice

The endogenous polyamine agmatine may be a new central neurotransmitter. Agmatine‐like immunoreactivity has been described in numerous brain regions (such as the hypothalamus and amygdala), long thought involved in the control of aggression. Consequently, the present study examined agmatine's (2.5–80 mg/kg, ip) effects on behavior directed by isolated male mice to anosmic partners in a neutral area. The videotaped encounters were analysed in terms of 10 broad behavioral categories. Agmatine did not appear to be involved in the modulation of aggression or anxiety in this test. Aggr. Behav. 31:000000, 2005. © 2005 Wiley‐Liss, Inc.     

Further experiments on the social interactions of domestic “Norway” rats

Domestic rats, Rattus norvegicus, aged nearly one year, were studied in artificial colonies in large cages with attached nest boxes. As in previous experiments on younger domestic rats, but not those on wild rats, the colonies were peaceful. Questions concerning the “aggressive” or “agonistic” behavior of domestic rats are further discussed.     

Genotype and environment in the social interactions of wild and domestic “Norway” rats

Wild rats, Rattus norvegicus, (a) trapped as adults or (b) of the second generation in captivity (lab-wild), and domestic rats of two strains, were studied for 28 days in artificial colonies in large cages with attached nest boxes. Controls were kept in mated pairs in small cages. Each colony consisted of six males and six females. The interactions of the males in six colonies of trapped rats were highly “stressful;” 61% died; and most of the survivors lost weight and had greatly enlarged adrenals. In each colony, however, there was a male (an alpha) that gained in weight and spent much time, during the dark hours, in the open on the floor of the cage; and in three colonies there were also other males (“betas”) that gained in weight. The adrenals of alphas and betas weighed about the same as those of the controls. In one of the 12 colonies of domestic rats one male behaved like a wild male; but in the other colonies the males gained in body weight and their adrenal weights resembled those of the controls. In three colonies of lab-wild rats 22% of the males died, but there was no evidence of males of different status. The findings confirm that the “agonistic” behavior of domestic rats is usually much attenuated in comparison with that of the wild type; a number of methodologic implications are discussed.     

Genetic analysis of “Spontaneous” intermale aggression in mice

“Spontaneous” intermale aggression was investigated in seven inbred strains of mice. A positive interstrain correlation and cross-correlation was found for two indices of fighting intensity, ie, accumulated attacking time and number of attacks. The strain aggressiveness level (percent of mice fighting in each strain) does not correlate with the intensity of aggressive behavior. It has been shown by using a genetical analysis performed on C57BL/6 and BALB/c strains, their reciprocal F₁ hybrids, and back-crosses that these indices of intermale aggression are under different genetic control. Aggressive behavior intensity depends on the additive effects of genes. The control of strain aggressiveness level revealed that a high level of aggressiveness was dominant. No reciprocal effects were found. The level of aggressiveness and the intensity of fighting seem to represent different aspects of aggression and may be controlled by different genetic mechanisms.     

The assessment of individual “Aggressiveness” in pigeons by a variety of means

Pigeons attack or threaten animate and inanimate targets. The assessment of their aggressiveness was studied by exposing them in their home cages to three different stimuli: the experimenter's hand, a live pigeon, and a rear-projected conspecific image when the birds were exposed to intermittent access to food. A positive correlation between the hand test and live pigeon test was evident, but no relationship between either of these responses and the response to a pictorial image was observed. These results combined with other ethological observations cast doubts on the usefulness of schedule-induced responses to pictorial targets in the assessment of the individual aggressiveness in pigeons, but suggest that the hand test is an adequate and reliable procedure for such evaluations.     

“Weapons effect” revisited: Motor effects of the reception of aversive stimulation and exposure to pictures of firearms

The effect of presenting images of firearms on the speed of clenching of the fist of human subjects simultaneously receiving an aversive stimulation was studied. It was thought that, whereas the classic interpersonal experimental situation confounds the effects of the stimulus presented and several interpersonal processes, speed of fist clenching in a noninterpersonal setting could constitute a valid measure of the subject's readiness to fight. Twenty-four male and 24 female students (ages > 20 and <36 years) were instructed to press with their right hand a device commanding the projection of slides upon reception of an acoustic signal. Speed of clenching of the hand was recorded in the four conditions generated by the combination of two levels of acoustic signal (aversive and nonaversive) and two modalities of slides (firearms or tools). The results show that the reception of aversive sound accelerates fist clenching. Simultaneous presentation of slides of firearms and reception of aversive noise increases the speed of clenching of the fist. The slides' main effect was not significant. More irritable subjects tend to execute this movement faster than their less irritable counterparts, and more emotionally susceptible subjects tend to be slower than less susceptible ones. Male subjects were faster than females. This pattern of results is discussed in relation to the hypothesis formulated by the authors.     

Effects of acute,subchronic and intermittent MDMA (‘ECSTASY’) administration on agonistic interactions between male mice

Recent studies suggest that acute administration of 3,4‐methylenedioxymethamphetamine (MDMA), an amphetamine derivative popularly known as “ecstasy,” produces an antiaggressive effect in male mice. However, there is no evidence with respect to the development of tolerance or sensitization after its subchronic or intermittent administration. In this study, we examined the action of low to moderate doses of MDMA (1.25, 2.5 and 5 mg/kg, i.p), administered acutely, subchronically (for 7 days) or intermittently, on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic “standard opponents” 30 minutes after the drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. Acute treatment with MDMA provoked a significant reduction of aggressive behaviors, without altering immobility. However, this action was only selective at 1.25 mg/kg. With the intermediate (2.5 mg/kg) and the highest doses (5 mg/kg) of the drug, it was observed a significant decrease of offensive behaviors, accompanied by an increase of exploration from a distance, avoidance/flee and defense/submission behaviors. This ethopharmacological profile could indicate the existence of an anxiogenic‐like effect of MDMA. The overall picture of the effects of MDMA was very similar in the acutely, intermittently and daily treated animals. No tolerance or sensitization to the actions of the drug was developed after its repeated or intermittent administration.     

Activity of creatine kinase in mice under various “Stress” conditions

“Stress” induced by swimming, immobilization, and fighting in male albino mice results in a significant increase of creatine kinase (CK) activity in blood obtained by decapitation. The increase partially depends on motor activity as shown in fighting animals. Males show higher CK values than females. Isolation and even immobilization also lead to higher CK activity, the latter to a similar extent as swimming and fighting. We believe that CK activity is regulated by processes additional to motor activity.     

ECONOMY OF “INVISIBLE DEBT” AND ETHICS OF “RADICAL HOSPITALITY”: Toward a Paradigm Change of Hospitality from “Gift” to “Forgiveness”

The purpose of this paper is to reconstruct a Christian theology of “hospitality” through a critical reading of Jacques Derrida and Friedrich Nietzsche as well as through an in‐depth biblical and theological reflection on the ethics of hospitality. Out of this reconstructive investigation, I propose a new Christian ethics of hospitality as a radical kind. As a new paradigm, this radical hospitality is distinguished from other types in that it is no longer conceived on the model of “gift”. The new Christian ethics of hospitality is rather reconstructed on the model of “forgiveness” by critically appropriating the concept of “invisible debt” that lies between the hosting citizens and the migrants in the senses of “you owe us your presence” and “I owe you my security and success.” While the hospitality of the gift defines the relationship between the hosting citizens and the migrants as givers and givees, the new paradigm of hospitality identifies this relationship as between creditors and debtors. In this regard, a new Christian hospitality called for unto citizens of the hosting society is a radical kind that challenges them to transcend the creditor‐debtor consciousness.     

“We're not friends anymore! unless…”: the frequency and harmfulness of indirect,relational, and social aggression

The frequency of items of indirect, relational, social, verbal, and physical aggression was assessed in the school environment of 422 adolescents, using the Indirect/Social/Relational Aggression scale (ISRA), a measure that combined items from indirect, relational, and social aggression research. We also assessed the perceived harmfulness of each item. Comparing these findings with the occurrence of aggression on television, we found that adolescents were exposed to nearly 10 times more indirect, relational, and social aggression on television than they are in school. Overall, there was no sex difference in the amount of aggression reported by boys and girls. However, when examining specific items, girls reported more gossiping and boys more hitting. Girls perceived indirect, direct relational, and verbal aggression as more harmful than did boys. Limited evidence was found for a distinction between indirect, relational, and social aggression, although it was clear that they were more similar than different. Aggr. Behav. 32:1–14, 2006. © 2006 Wiley‐Liss, Inc.     

Behavioral profile of L–741,741, a selective D4 dopamine receptor antagonist,in social encounters between male mice

Although the role of dopamine D1–D2–D3 receptors in the modulation of aggression has been extensively documented, there is not information with respect to the implication of D4 receptor. The aim of this study was to examine the acute effects of L–741,741 (0.75, 1.5 and 3 mg/kg, i.p), a selective D4 receptor antagonist, on social encounters between male mice using an ethopharmacological approach. Ten min of diadic interactions were staged between a singly housed and an anosmic mouse in a neutral area. These encounters were videotaped and the accumulated time allocated by subjects to ten broad behavioral categories was estimated. Besides other behaviors, the aggressive and motor behaviors were evaluated 30 min after injection using an ethologically based analysis. L–741,741 did not affect significantly offensive behaviors (threat and attack), as compared with the control group. Likewise, motor and anxiety‐related behaviors (such as social investigation, avoidance/flee or defense submission) were not altered after drug administration. These results suggest that dopamine D4 receptor is not involved in the modulation of aggressive behavior. Aggr. Behav. 29:552–557, 2003. © 2003 Wiley‐Liss, Inc.     

“Frenemies,Fraitors, and Mean‐em‐aitors”: Priming Effects of Viewing Physical and Relational Aggression in the Media on Women

Past research has shown activation of aggressive cognitions in memory after media violence exposure, but has not examined priming effects of viewing relational aggression in the media. In the current study, 250 women viewed a video clip depicting physical aggression, relational aggression, or no aggression. Subsequent activation of physical and relational aggression cognitions was measured using an emotional Stroop task. Results indicated priming of relational aggression cognitions after viewing the relationally aggressive video clip, and activation of both physical and relational aggression cognitions after viewing the physically aggressive video clip. Results are discussed within the framework of the General Aggression Model.     

While We Wait: The Foolishness of Scarcity,the “Devalued Other,” and Pedagogies of “Becoming”

This article considers how Christian women leaders might, in the absence of global economic equality for women, reframe theological dialogue that affirms the work and worth of the “devalued other” – 21st‐century women living in economic insecurity – and to declare that Jesus' eschatological hope is in the feminization of abundance. The article engages the parable of the wise and foolish virgins as a messianic requirement to deconstruct the barriers that keep the devalued other from seeing her full potential and to challenge the foolishness of scarcity that has taken hold of the daughters of privilege. It seeks to engage an African feminist hermeneutic as the primary methodology and to craft an emerging pedagogy of “becoming” that speaks to the cosmic shift to strengthen the agency of women as we await the coming Parousia.     

Psychopathy and the ability to read the “language of the eyes”: Divergence in the psychopathy construct

The capacity to interpret others people's behavior and mental states is a vital part of human social communication. This ability, also called mentalizing or Theory of Mind (ToM), may also serve as a protective factor against aggression and antisocial behavior. This study investigates the relationship between two measures of psychopathy (clinical assessment and self‐report) and the ability to identify mental states from photographs of the eye region. The participants in the study were 92 male inmates at Bergen prison, Norway. The results showed some discrepancy in connection to assessment methodology. For the self‐report (SRP‐III), we found an overall negative association between mental state discrimination and psychopathy, while for the clinical instrument (PCL‐R) the results were more mixed. For Factor 1 psychopathic traits (interpersonal and affective), we found positive associations with discrimination of neutral mental states, but not with the positive or negative mental states. Factor 2 traits (antisocial lifestyle) were found to be negatively associated with discrimination of mental states. The results from this study demonstrate a heterogeneity in the psychopathic construct where psychopathic traits related to an antisocial and impulsive lifestyle are associated with lower ability to recognize others' mental states, while interpersonal and affective psychopathic traits are associated with a somewhat enhanced ability to recognize others' emotional states.     

The relationship between aggressive and sexual behavior in male mice: Effects of testosterone and parachlorophenylalanine

The purpose of this study was to clarify the connection between aggressive and sexual behavior with the aid of testosterone propionate (TP) and parachlorophenylalanine (PCPA). Previous studies have indicated that aggressive and sexual behavior are positively correlated, and it has been suggested that both behaviors are related to the level of general arousal. Testosterone has documented effects on both aggressive and sexual behavior. It has been hypothesized that these effects are due to an increased level of general arousal. If this is the case, aggressive and sexual behavior could be restored by administration of drugs excitating the central nervous system, e.g., PCPA. The present study examined the effects of TP and PCPA on aggressive and sexual behavior in gonadectomized male mice. Control animals were injected with sesame seed oil or saline. The level of aggressiveness was assessed by means of dyadic tests with gonad-intact male opponents. For the sexuality tests, a receptive female was placed in the home cage of the experimental male. The results showed that male mice injected with PCPA were more aggressive than the males of the other groups, while the TP-exposed males expressed the most sexual activity. Compared to the control group, the PCPA and TP groups were more active in both the aggression and the sexuality tests. These findings lend support to the hypothesis that the earlier documented correlations between aggressive and sexual behavior could be due to both behaviors being dependent on a certain level of general activation. Aggr. Behav. 24:367–377, 1998. © 1998 Wiley-Liss, Inc.