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P-20.-Social defeat in C57BL/6 mice induced exaggerated fear and inhibition of territorial marking in response to aggressor’s urine. 

Lumley, L.A., Robison, C., Chen, W.K.,  Saviolakis, G.A. and Meyerhoff, J.L. 
Department of Neuroendocrinology, Division of Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA.

Social defeat (SD) has marked and prolonged behavioral effects, including avoidance of a non-aggressive intruder and inhibition of territorial urine marking in response to both male and female mice.  We examined whether SD-induced exaggerated fear and inhibition of marking would generalize given exposure to aggressors’ urine.  In a modified resident-intruder test, mice were exposed within their home cages to bedding removed from aggressors’ cages.  The bedding was placed on the opposite side of a perforated barrier, relative to the resident subject mouse.  SD mice displayed more avoidance, flights, crouch defense, and Straub tail in response to aggressors’ urine placed on the other side of a perforated barrier, than did NOSD mice.  In addition, SD mice had more risk assessment, including stretched-approach and stretched-attend posture than NOSD mice.  NOSD mice displayed more dig behavior, especially at the front of the cage.  When the barrier was removed, SD mice continued to display increased flights, crouch defense, Straub tail and risk assessment.  NOSD mice spent more time in proximity of the aggressors’ bedding and sniffed the bedding more than did SD mice.  In a test of territorial urine marking, SD mice displayed less marking in response to both aggressor urine and within a novel empty cage, relative to NOSD mice.  NOSD mice displayed increased marking with repeated tests, but SD mice did not.  In sum, the exaggerated fear responses and inhibition of territorial marking generalize to olfactory cues from aggressive mice.

 

P-21.- Development of locally shared attitudes toward aggression: Dynamic Social Impact Theory

Curtayne, E., Hur, T., Morio, H., Richardson, D. and Latané, B.

Recent research on the “culture of honor” as an explanation for relatively high levels of violence in the United States South presents evidence on aggression in particular social contexts that associate aggressive retaliation with threats to personal honor (Nisbett and Cohen, 1996). The present study examined the process by which attitudes that associate violence with honor might develop and maintain in delineated regions. Dynamic Social Impact Theory (DSIT; 1996) proposes the strength, immediacy, and number of persons in social environment as the determinants of interpersonal influence on an individual’s attitudes or beliefs. It suggests that these factors will act upon the individual(s) and lead to an emerging pattern of shared beliefs at the group level. Also, the exchange of information within a defined social space, influenced by the persuasibility and number of “neighbors,” will produce local clusters of attitudes. Therefore, DSIT predicts group-level clustering and consolidation of attitudes or beliefs as a function of individual-level social influence. The present research investigated the effects of interpersonal interaction on development of attitudes or beliefs about aggression (broadly, regionally shared cultures or values). The present study utilized a group-brainstorming paradigm as an interpersonal interaction setting.  Participants were randomly assigned to small groups of 3-4 people and conducted a series of group-brainstorming task about four aggression-related topics.  They, then, completed questionnaires including aggression-related items (that were designed to assess social representations of aggression; culture of honor) and a non-aggression items (specifically, judging moral appropriateness of various social behaviors). Clustering indexes (d) – a ratio between differences of a participant’s rating from their own group members’ ratings and those of the outside-of-group others’ ratings – were calculated on both the aggression items and the non-aggression items separately.  Consistent with the prediction, participants’ ratings on aggression-related items, but not those on non-aggression items, were significantly clustered after group-brainstorming tasks about aggression-related topics.  This finding showed that social interactions, even group brainstorming focusing on divergent thinking processes, results in locally shared attitudes (or beliefs). Furthermore, it suggests that Dynamic Social Impact may be the underlying mechanism of development of regional cultures (or values).

P-22.- Bullying at schools: a pilot study using semi-structured interviews

Gutiérrez, H., Barrios, A., van der Meulen, K., Hoyos, O. And del Barrio, C.
Department of Developmental Psychology and Education. Autonomic University of Madrid, Spain

Throughout life, but especially in childhood and adolescence, peer relationships are important experiences in a person’s development. However, in some cases, peer relationships may become conflictive and lose their positive influence, thus turning into something fearful. This is what happens with bullying at schools, a type of aggressive behaviour, which can take a variety of forms. Often it is assumed by adults to be a normal and infrequently occurring phenomenon. As a result, it is difficult to identify types of bullying and become aware of its damaging consequences. Ever since research interest in bullying began, questionnaires have been the normal instrument for studying the phenomenon. In this pilot study the method employed has been that of the semi-structured interview, based on the Piagetian clinical method (Piaget, 1926, 1947; Turiel, 1983; Castorina et al, 1989). A sample of 36 participants was used, belonging to three age groups: children (9 – 11 years), adolescents (13 – 15 years) and adults (18+ years). Half the sample was interviewed at schools in Madrid and the other half at schools in Oviedo. In the frame of a wider study, an analysis was carried out which extracted categories corresponding to the following aspects: nature of bullying, dynamics of the relationship (origin, maintenance, ending, and consequences of the bullying episodes) and the emotions attributed to aggressors, victims and bystanders. The information gathered using the semi-structured interview revealed an age effect in the way children, adolescents and adults approach many issues related to the phenomena of peer maltreatment. The shift from primary to secondary school is confirmed as the time during which this type of situation occurs more frequently. This study shows the possibilities that the semi-structured interview offers for a deeper knowledge of bullying. [1] This study forms part of the European TMR network project: The nature and prevention of bullying [1] For more information on the situation of bullying in Spain, please refer to the Informe Nacional del Defensor del Pueblo sobre Violencia Escolar, in which the authors of this poster participated.

P-23.- Different social stress situations, splenic Norepinephrine, Interleukin-1 and Interleukin-2 contents, and serum corticosterone levels in male mice

Fano, E., Sánchez, J.R., Arregi, A., Castro*, B., Alonso*, A., Brain** , P.F.  and Azpíroz, A.
Department of Basic Psychological Processes and their Development, Basque Country University, San Sebastián, Spain. *Department of Cellular Biology and Morphological Sciences, Basque Country University, Leioa, Spain. **School of Biological Sciences, University of Wales Swansea, Swansea, U.K.

Two different social stress situations (cohabitation in pairs or fixed dyadic interactions) were assessed for their effects on splenic contents of norepinephrine (NE), Interleukin-1 (IL-1) and Inerleukin-2 (IL-2), and  on serum levels of corticosterone in male OF1 strain mice. Two durations were used for each of the social stress paradigms,  namely  6 or 16 behavioral tests for fixed dyadic interaction animals and 6 or 16 days of cohabitation for cohabiting subjects. After 2 weeks of individual housing, 24 animals were allocated to cohabitating or fixed dyadic interaction pairs for both durations. Serum corticosterone titers were generally higher in interacting pairs and subordinates, than in cohabiting animals and dominants. Dominants had higher levels of IL-1 than subordinates and the dyadic encounter exposed animals showed higher levels than cohabiting counterparts. Spleen  IL-2  did not respond in the same way as IL-1 to the treatments (social status, paradigm and duration). IL-2 levels are higher in cohabiting animals and the effect is strongest in the acute category. The stress of acute experiences (seen in both dominant and subordinae) may stimulate IL-2 levels but this response declines with time. Spleen NE contents did not significantly differ. The differences in splenic interleukin contents could not be directly related to observed changes in serum corticosterone levels. This suggests that different mechanisms regulate changes in glucocorticoids and the measured cytokines. These physiological phenomena are not solely  related to the animal’s social status (dominant or submissive). The intensity and duration of the agonistic behavior displayed and the amount of interaction experience accumulated, may account for the observed differences. On the whole, results in the present study support the idea that stress does not affect different immunological measures in a simple, consistent way and that the role of endogenous glucocorticoids in immunoregulaion could be less clear-cut than studies with synthetic glucocorticoids  have led us to believe.

P-24.- REWARDING PROPERTIES OF TESTOSTERONE IN MALE MICE DIFFERING IN THEIR BASAL LEVELS OF AGGRESSIVENESS.

Arnedo, T., Salvador, A., Martínez-Sanchis, S. and Pellicer, O. Area of Psychobiology, Faculty of Psychology, University of Valencia, Valencia, Spain.

Testosterone derivatives have been widely abused, and dependence has been reported for some individuals. A few studies suggest that basal levels of aggressiveness could be relevant to explain individual differences that could mediate vulnerability to developing dependence. Rewarding properties of testosterone involve the dopaminergic system that has been shown to be different in aggressive and non-aggressive male mice. The present study was carried out to explore whether the basal levels of aggressiveness could modulate the rewarding properties of  4-androsten-17 b-lo-3-one testosterone (T) in intact male mice using the conditioned place preference (CPP).  After three weeks of isolation, experimental animals were pre-screened for aggressive behaviour. Tests finished when the experimental animals attacked for the first time or after 10 minutes without attacking, being classified either in short attack latency group (SAL) if they attacked before the fifth minute of the encounter or in long attack latency group (LAL) if they attacked afterwards. The CCP procedure started five days later, involving three phases: preconditioning test (one session); conditioning (eight sessions); and post-conditioning test (one session). SAL and LAL animals were allocated to three groups of treatment, forming six experimental groups: SAL + vehicle (n=12); SAL + 1 mg/kg T (n=12); SAL + 2 mg/kg T (n=12); LAL + vehicle (n=12); LAL + 1 mg/kg T (n=12); LAL + 2 mg/kg T (n=12). In the preconditioning test, subjects were allowed to explore the environment for 30 minutes in order to determine the initial preference for the floor textures, which were different in each compartment under non-drug conditions. In the conditioning phase in every session each mouse was injected with testosterone or vehicle and 30 minutes later was confined in the apparatus for 30 minutes. CPP assessments followed the last conditioning session by 24 hours. CCP was observed after 1 and 2 mg/kg administration of testosterone, although these doses had similar rewarding effects in SAL and LAL animals. Data were reanalysed selecting animals above percentile 70 (n=21) and below percentile 30 (n=21) in the latency of attack but no differences in CCP were found between these groups.  

P-25-Domestically Violent Men: Cognitive Processing Patterns in Response to Social Interactions

Porter, A., Epps, J., Anderson, D. and Granucci, B
Department of  Psychology, University of South Florida, Tampa, Florida, USA.

Much of the current research in the area of domestic violence against one’s intimate partner, or battering, has it's roots in the research base established for cognitive and behavioral processes and aggression. The Social Information-Processing theory is a commonly used model in this area which outlines a series of steps which precede a behavioral response.  The steps are (1) encoding cues, (2) interpretation, (3) response consideration, (4) response decision, and (5) enactment.  Biased or deficient processing at each of the steps will contribute to deviant or aggressive behavior.  Skillful processing at each step will lead to socially competent performance within the situation.The current study examined the social skills of fifty-four domestically violent and nonviolent men.  The participants read thirteen scenarios depicting problematic hypothetical situations involving either the participant or his wife, or the participant and a non-intimate female associate.  Open-ended reports of behavioral response were rated for presence of skillful processing at various steps within the model.   Differences were found between the violent and nonviolent groups at certain processing steps. Domestically violent men were less likely to attribute the cause of the negative interaction to nonhostile social cues than their nonviolent counterparts.  They were less likely to attribute the cause of the problem to circumstances beyond the other person’s control.  Domestically violent men were also less likely to choose a prosocial response option, such as proposing a problem-solving strategy or using open direct communication than their nonviolent counterparts. They were more likely to choose a response that was inept, such as sulking or doing nothing.  In addition, when asked to recall information about the social interaction, violent men had more difficulty remembering critical details of the interaction.  These processing patterns were similar in both types of social relationships.  In addition, the patterns were similar regardless of the level of negative emotional arousal. Based on the results of this study, it is suggested that treatment for domestically violent men include training in social cue reading and recall, and behavioral role plays of prosocial interactions.  

P-26.-A review of the principal theoretical models used to explain aggressive behaviour today and road safety applications

Saiz-Vicente, E. J. and Pollock, D.
University Institute of Traffic and Road Safety (INTRAS), University of Valencia, Spain

In our society today, unfortunately, few topics are as popular as human violence and aggression. It is undeniable that we are immersed in a highly aggressive social environment in which violent behaviour is frequently used to gain ones objectives, and with consequences that can often be quite serious. The road environment is not exempt from the expression of violent behaviour. It is not uncommon to encounter drivers who are hostile at the wheel, whose conduct can contribute to traffic conflicts and accidents. Psychologists have developed theories that can predict and to a large extent explain violent behaviour. Within the behavioural sciences, few topics have produced such fierce debate during the last decades as the study of human aggression. The enormous quantity of publications produced and during the last few years, and that continue to be published, is proof of the amount of interest that this topic has attracted. The objective of this investigation is to provide evidence of the interest and concern for the topic of aggression and violence that exists in the behavioural sciences in general and within the field of Road Safety in particular. This study is based on a review of the literature published during the past 30 years which is referenced in the computerised database Psyclit. The bibliographic analysis of these publications provides the following information: (a) the major authors within this field, (b) the principal proponents of each psychological theory, (c) the major journals within this field. In addition, the publications will be classified into one of two major categories, depending on whether they place more emphasis on individuals innate character traits or on the social environment that surrounds the subject as the origin of the aggression. Lastly, the theories and models that have been proposed to explain aggression and violence on the road will be described.

P-27.-Effects of N6-Cyclohexyl-adenosine (CHA) on isolation-induced agression in male mice

Navarro, J.F., Romero, C., Maldonado, E., Pedraza, C. and Dávila, G.
Area de Psicobiología, Facultad de Psicología, Universidad de Málaga, Spain

Adenosine exerts numerous physiological actions in the central nervous system, being its effects mediated through four receptor subtypes: A1, A2a, A2b and A3. Several studies have suggested an involvement of adenosine receptors in the modulation of aggressive behaviour. However, the influence of adenosine Aq agonists on aggression is scarcely known. In this study, we examined the effect of  N6-cyclohexyl-adenosine (CHA; 0.025-0.4, i.p.), a selective adenosine A1 receptor agonist, on agonistic behaviour elicited by isolation in male mice. Individually housed mice mere exposed to anosmic “standard opponents” 60 min after drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. CHA exhibited an ethopharmacological profile characterised by a selective decrease of offensive behaviours (threat and attack) at intermediate dose (0.1 mg/kg), without impairment of motor activity. In contrast, the antiaggressive action of the highest doses used (0.2 and 0.4 mg/kg) was accompanied by a mared increase of immobility. Although inhibition of aggression in solated male mice couid be a direct effect on the neuron via altered levels of cAMP, or a result of alterations in intracellular Ca++ levels, the behavioural effects observed in this study couid be also related to an adenosine modulatory action on other neurotransmitter systems. In this stydy could be also related to an adenosine modulatory action on other neurotransmitter sysstems.In this sense, it is known that adenosine agonists may inhibit the release of dopamine and increase the release of serotonine, two neurotransmitters which have been classically implicated in aggression. In fact, it has been widely documented that dopaminergic antagonists and serotonergic agonistis reduce aggressive behaviour in numerous animal models (1-3). Further studies are required to evaluate the effects of the interaction between adenosine A1 agonists and dopaminergic/serotonergic compounds on aggression. Manzaneque JM, Navarro JF (1999). Aggressive Behavior, 25, 225-232.Navarro JF, Maldonado E (1999). Progress in  Neuropsychopharmacology & Biological Psychiatry, 23, 327-334. Navarro JF et al. (2000). Progress in Neuropsychopharmacology & Biological Psychiatry, 24, 131-142.

P-28.-Spatial learning in isolated- and social-reared mice with short and long attack latencies: effects of nicotine.

Moragrega, I., Oterino,  M.C., Vicens*, P., Redolat, R. and Carrasco, M.C.
Area of Psychobiology, Faculty of Psychology, University of Valencia, Spain.
* Department of Basic Psychology, Clinical and Psychobiology, Faculty of Psychology, University Jaume I. Castellón, Spain.

Previous studies have shown that aggressive mice show better performance in some learning tasks than non aggressive ones. In addition, male mice of different social status and with diverse aggressive characteristics display variations in their reactions to novelty. The main aim of the present study was to investigate whether there were differences in the acquisition and retention of the Morris water maze between NMRI mice with “short attack latency” (SAL) and “long attack latency” (LAL). This strain was used since isolation rearing may induce high levels of aggressive behavior in some animals and they also show a good spatial learning. Two hundred NMRI  male mice were randomly assigned to two experimental housing conditions: grouped or isolated for 5 weeks. After this period an aggression test took place in order to classify the animals into SAL (latency to the first attack shorter than 150 sec) and LAL mice (latency to the first attack longer than 240 sec). Three groups were obtained: isolated-SAL (ISO-SAL), isolated-LAL (ISO-LAL), and grouped-LAL (GR-LAL). The effects of a daily sc injection of nicotine (0.175 mg/kg) or saline administered 15 min before the performance of the water maze, were compared in each group. In the acquisition of this spatial task animals must reach a platform submerged in the water and in the retention, mice are evaluated in a probe trial, a test in which  the platform is removed. It was observed that there were no significant differences between groups in the acquisition of this spatial task. However, when the retention of the task was evaluated in a probe trial, results indicated that both saline-treated ISO-SAL and ISO-LAL had a better performance than saline-treated GR-LAL. No significant differences were observed in the nicotine-treated groups. In conclusion, our data suggest that isolated mice show a better retention of the platform location than grouped mice, although differences in attack latencies in NMRI mice do not seem to be correlated with spatial learning ability.

P-29.- Direct and indirect aggression: a comparison between Iranian and Spanish students

Musazahdeh, Z., Andreu*, J.M., Sánchez*, D. and Ramirez*, J.M.
University Complutense of Madrid, Spain-Iran, *University Complutense of Madrid, Spain

Different forms of aggression have been classified into two types: Direct Aggression (such as physical attack, hitting, and verbal abuse), and a more subtile Indirect Aggression (such as intimidation of your opponent, social isolation, or no face-to-face contact). It is of interest to find out if there are sexual differences between these two kinds of aggression. Björkquist's scale of direct and indirect aggression  (D.I.A.S) was applied to 1050 students (457 boys and 595 girls) of various educational levels (College and University) in Iran and Spain. The average age was 18 years old. Factor analysis confirmed the factorial structure of the questionnaire in both populations.

Direct Aggression and Indirect Aggression, as well as the degree of justification of aggressive acts (presented in a different paper) were all positively correlated with the level of aggressiveness of the subjects.

Sexual differences suggested in previous studies were confirmed. The level of direct aggression was higher in males, whereas females showed more indirect aggression, in both countries.

Another important factor was age. In both populations, the younger College students showed higher level of both, Direct and Indirect Aggression, than the older University students, in Iran and in Spain.

Finally, Spanish students, both boys and girls, showed a higher level of aggression than Iranian students of both sexes.

In few words, age, sex, and culture seem to influence in the level and kind of aggression.

This study forms part of the European TMR network project: The nature and prevention of bullying

For more information on the situation of bullying in Spain, please refer to the Informe Nacional del Defensor del Pueblo sobre Violencia Escolar, in which the authors of this poster participated.