The influence of the Y-chromosome of Rb/1Bg mice on agonistic behaviors

Males of the Rb/lBg and C57BL/10Bg strains, as well as of the Bl0RblF, and RblBlOF1, reciprocal hybrids, were tested for aggression over three daily trials beginning at 50 days of age. The BlORblF, hybrids were sired by Rb/lBg males, and the RblBlOF, hybrids were sired by C57BL/10Bg males. The mean scores for the agonistic acts of chase, wrestle, flank-bite (but not tail rattle or attack), and the mean “aggression” score (but not mean latencies to first agonistic act or first attack) were significantly higher for BlORblF, than for RblBlOF, hybrids. These findings are consistent with the hypothesis that some aspect(s) of the Rb/lBg Y-chromosome strain can influence the occurrence of some of the motor patterns of offense but not defense. The Y-chromosomes of the DBA/1, DBA/2, CBA, and PHH inbred strains have a similar effect on agonistic behaviors.     

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.     

Mate choice in the domestic cat (Felis silvestris catus L.)

The domestic cat (Felis silvestris catus L.) has colonized different types of environments that differ in their spatial distribution of resources. Urban environments are characterized by highly clumped distributions of food and shelter, allowing domestic cats to live in large multimale‐multifemale groups. In such a situation, questions arise about male and female mating strategies. In particular, do females exert active mate choice? We tested this question using behavioural records on acceptance and refusal of males by estrous females. Our results showed that most females copulated with several males during a single estrus period. The variability of female behaviour was high: six females copulated with all courting males whereas three others mated with most courting males; six others copulated with half or less of the courting males. Even if some females copulated with certain males more often than with others, the identity of the most successful males changed each time. These results show that most females did not choose mates among different males available. The results are discussed in terms of optimal reproductive strategies of males and females in an urban environment. Aggr. Behav. 26:455–465, 2000. © 2000 Wiley‐Liss, Inc.     

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.     

Cholinergic modulation of tonic immobility in the rabbit (Oryctolagus cuniculus).

The present study was performed to determine the effects of the anticholinergic agent scopolamine and the cholinergic agent physostigmine on tonic immobility in rabbits. Recordings of the electroencephalographic (EEG) activity from cortex and hippocampus were also made before, during, and after each test session. Scopolamine significantly prolonged the response and produced large amplitude slow wave activity in the EEG of both cortex and hippocampus. Physostigmine significantly shortened the duration of immobility and increased rhythmic slow activity in the frequency range of 5.5-9.1 Hz in the hippocampus while producing a desynchronized cortical rhythm. It is suggested that the cortex and hippocampus play a role in modulating tonic immobility duration by inhibiting the brain-stem structures thought to control this response.     

The introduction of a group of alien mice (Mus musculus L.) into hierarchically organized groups of five male mice

Groups of 3 male or female Mus musculus were introduced into hierarchically organized colonies of 5 male mice for a period of 8 days. The colonies were of 2 kinds; high-level aggressive (HLA), which had been set up 3 days prior to the introduction of the aliens, and low-level aggressive (LLA), which had been established for 21 days before strangers were introduced. Both males and anestrous females were attacked, but males were attacked 5 times more frequently than females. In HLA colonies most of the attacks on the aliens were by the dominant; in LLA colonies there was no difference in the behavior of dominant and subordinate mice toward strangers. Both aggression toward aliens and intracolony aggression declined over the 8 day experimental period. In HLA colonies the dominant mouse mounted females 5 times more frequently than did either his subordinates or male mice in the LLA colonies. In HLA colonies aliens huddled with subordinates to form a single colony with 1 dominant and 7 subordinates. In LLA colonies alien males remained as a discrete group spatially separated in the cage. Female aliens were incorporated into the main colony. In all cases dominant male mice made more attacks on aliens as compared with familiar mice.     

Diversity in agonistic behavior of croaking gouramis (Trichopsis vittata,T. schalleri,and T. pumila; Anabantoidei) and the paradise fish (Macropodus opercularis; Anabantoidei)

Agonistic encounters of all three species of the vocalizing genus Trichopsis were observed in order to compare species-specific fighting strategies and the specific investment in acoustics. Additionally, these encounters were compared to agonistic encounters of Macropodus opercularis which was considered to be mute. The aim of this comparison was to investigate if mute fishes stress visual or tactile displays. Within the genus Trichopsis, significant differences among the three species were found in qualitative and quantitative analysis of displays. Frontal display occurred only in Trichopsis vittata, whereas a strong tail-beating while vocalizing was only observed in Trichopsis pumila. Fight duration and the number of sounds and circlings were highest in Trichopsis schalleri. The largest relative distances between circling opponents occurred in T. pumila, the smallest species. Also, the number of attacks was lowest in T. pumila. Fighting assessment seemed to be different in each species. For the first time, sound production has been reported for Macropodus opercularis (infrequently and with extreme low sound pressure levels), but much more investment in visual and tactile displays has been demonstrated. Lowering the branchiostegal membrane and spreading the opercula occurred only in M. opercularis and was never observed in any of the Trichopsis species. The number of attacks was higher in Macropodus than in any Trichopsis species. The relative distance between Macropodus opponents while circling was closest compared to the three Trichopsis species. Visual and contact displays are reduced in extensively vocalizing fish species, like Trichopsis sp., compared to mute or seldom vocalizing species, like Macropodus. © 1996 Wiley-Liss, Inc.     

Using positive peer reporting to improve the social interactions and acceptance of socially isolated adolescents in residential care: a systematic replication

We studied how rewarding youth in residential care for publicly reporting positive social behavior influenced the social interactions and acceptance of their most socially isolated peers. Results showed that the intervention resulted in substantial improvements in social interactions by the previously isolated peers. Peer acceptance ratings also improved for 2 of the target youths.     

Neuronal unit activity in the abducens nucleus during classical conditioning of the nictitating membrane response in the rabbit (Oryctolagus cuniculus).

Neuronal unit activity was recorded from the abducens (6th nerve) nucleus, the "final common path," during classical conditioning of the nictitating membrane (NM) response in the rabbit, with the use of a tone conditioned stimulus, an air puff unconditioned stimulus (UCS), 250-msec interstimulus interval, and 60-sec intertrial interval. Animals were given 2 days of conditioning training (104 trials in eight blocks per day) and 1 day of extinction. Control animals were given comparable periods of stimulus presentations, explicitly unpaired. Activity of small clusters of units--"multiple unit" recording--was compared with the amplitude-time course of the NM response. Between-blocks comparisons of neural and behavioral responses indicated an essentially perfect correlation during acquisition of the conditioned response (Day 1, r = .99; Day 2, r = .98) and a slightly lower correlation during extinction (r = .93) for the conditioning animals. Within-blocks comparisons indicated a close correspondence between the histograms of unit activity and the amplitude-time course of the NM response for the conditioning animals in all phase of training and for the control animals in the UCS trial blocks.     

Patterns of agonistic interactions in three species of macaque (Macaca mulatta,M fascicularis,M tonkeana)

Patterns of aggression and response to aggression were studied in three groups of macaques living in semiliberty, each group representing a different species: Macaca mulatta, M fascicularis, and M tonkeana. In Macaca mulatta, intensity of aggression is high (biting is frequent) and symmetry in aggression is low: the aggressee most often flees or submits. In Macaca tonkeana, in contrast, biting is exceptional, aggression is very often bidirectional, and appeasement behaviors are frequently observed. Intermediate patterns are found in Macaca fascicularis with, in addition, especially frequent mild forms of submission. It is argued that relationships exist between intensity of aggression, symmetry in aggression, and development of behaviors controlling aggresssion. Whether balances between these variables are species-specific is discussed.     

Behavioral consequences of agonistic experiences in the male S3 (Tryon Maze Dull) rat

Aggression occurring during an initial confrontation between two rats may result in significant behavioral changes in one or both animals. The present experiment was designed to study behavioral changes occurring in the course of an agonistic interaction and the consequences of winning or losing. In order to ensure winning, male CPB-S3 Tryon Maze Dull) rats were confronted with males of a more aggressive strain (Long Evans); and to ensure losing they were confronted with those of a less aggressive strain Wistar). Winners were tested against losers, this test being repeated after an interval of 17 days. Winners and losers were also tested with naive S3 opponents. Possible effects of winning and losing in nonagonistic behavioral tests were then examined. These measured open field activity, passive avoidance learning, and masculine sexual behavior. The results replicate and extend earlier findings using a different strain, indicating that significant and relatively permanent behavioral changes are induced in male winners and losers. Behavioral change is most prominent in the losers. Despite the behavioral differences between winners and losers in tests for agonistic behavior, no consistent differences were noted in any of the other behavioral tests.     

The reinforcing properties of aggressive vs nonaggressive social interactions in isolated male ICR mice (Mus musculus)

Isolated male ICR mice in a T-maze consistently selected the goal box which enabled them to fight another mouse if the alternative goal box allowed no social interaction (Experiment 1). However, if the alternative choice enabled the isolated mice to interact with another mouse through a mesh screen which prevented fighting, the preference for the opportunity to fight did not appear (Experiment 2). Because the visual, olfactory, and auditory stimuli available through the screen appeared to be as attractive as the stimuli provided by the additional opportunity to fight, it is not necessary to conclude that the stimuli reinforcing the choice behavior in Experiment 1 were provided by fighting. Since there is no compelling reason to conclude that fighting is a primary reinforcer for these isolated mice, it is not necessary to argue that the high incidence of isolation-induced fighting is the reflection of a primary aggressive motive.     

Habituation, sensitization, and redirection of aggression and feeding behavior in the three-spined stickleback (Gasterosteus aculeatus L.)

Three-spined stickleback males maintained in individual aquaria built nests and defended the entire aquarium as a territory. Adjacent compartments containing another male stickleback, a gravid female, or a nongravid female provided a social context within which to study the habituation and sensitization of aggression elicited by a conspecific male intruded into the subject's territory. Typical sensitization-habituation curves were found for all fish regardless of the kind of neighbor. However, behavior redirected as a result of the stimulation of the intruded male differed between conditions. The group with a male neighbor showed increased aggression toward the neighbor, the group with a gravid female neighbor showed courtship, and the group with nongravid female showed neither. A third behavior, nest building, showed no difference between conditions, a result providing little evidence for a simple explanation in terms of general arousal. A second experiment elicited the same motor response to the intruded stimulus, but the motivational category was changed by eliciting the behavior by presenting live brine shrimp. In this experiment, aggression did not change during habituation, but the waning predation was redirected to another food-securing behavior, picking at the substrate. The results provide evidence for the important role that social context plays in understanding the redirection of behaviors, a phenomenon predicted from an extension of the dual-process theory of habituation.     

Understanding AIDS preventive behavior with casual and primary partners in homosexual men: The theory of planned behavior and the information-motivation-behavioral-skills model

Abstract

This study examined whether components from the Information-Motivation-Behavioral-Skills Model, in particular information, added explanatory power to factors derived from the Theory of Planned Behavior with respect to predicting AIDS-preventive behaviors among gay men. Participants were recruited from a longstanding cohort study in Amsterdam. Multivariate regression analyses showed that concepts from the Theory of Planned Behavior could account adequately for intentions to use condoms with casual as well as with steady partners. Actual behavior was best predicted by past behavior. In addition, structural equation modeling demonstrated that the causal paths as posited by Theory of Planned Behavior had a good fit to the data. From the presented findings implications for preventive interventions can be drawn. Specifically, interventions to increase condom use with casual partners need to focus at improving perceived behavioral control regarding this behavior, for instance through skills training. Interventions aimed at safer sex within steady relationships should take into account that the HIV-status of the individual and his partner plays an important role in the occurrence of unprotected anal sex in a romantic dyad.     

The factor structure of the Social Axioms Survey II (SASII) in the South African context

The objective of this study was to validate the new Social Axioms Survey II (SASII). The study sample comprised university students (n = 793) as well as their family members and friends (n = 645). Confirmatory factor analysis (CFA) following an initial exploratory factor analysis yielded a five-factor model: social cynicism, social complexity, reward for application, religiosity, and fate control. The findings of this study support the use of the new SASII in South Africa for research purposes.     

Food choice in rats (Rattus norvegicus): the effect of exposure to a poisoned conspecific

Three experiments were conducted to examine the effects of exposure to a poisoned conspecific on subsequent food aversion in rats. In Experiment 1A, rats that had been aversively conditioned to a cocoa-flavored food were exposed to a poisoned conspecific that had eaten the same food. On the subsequent choice test, the animals increased their aversion to that food. These results were reconfirmed in Experiment 1B, in which a cinnamon-flavored food was used as the stimulus. In Experiment 2, subjects were first exposed to a poisoned conspecific and then conditioned to the food which the conspecific had eaten. On the test, they showed no sign of increased aversion to that food.     

Revolution and the counter-revolution: The conflict over meaning between P. B. Struve and S. L. Frank in 1922

Lecturer in the Lomonossov University, Moscow, specialist in the young Hegel; has also worked quite extensively on Russian prerevolutionary thought. Nikolaj Plotnikov is notably the co-editor of the recently re-published texts,Vekhi, Iz Glubiny in the collection 'Iz istorii oteestvennoj filosofskoj mysli' in conjunction withVoprosy Filosofii.     

Influence of dominance on the development of play fighting in pairs of male Syrian golden hamsters (Mesocricetus auratus)

In the highly social rat, male juvenile and adult subordinates initiate more playful contacts with dominant pairmates than vice versa. This study examined the effect of dominance on playful contacts in the relatively asocial golden hamster. Pairs of male hamsters were reared together from weaning, and their play was filmed in the juvenile (28-36 days) and the young adult (60-70 days) stages of development. By the adult stage, it became clear that one pairmate was dominant over the other. The dominant pairmate launched all aggressive attacks (i. e., bites to the lower flanks and rump), and the subordinate pairmate performed all the submissive gesturing (e. g., tail up submissive posture). Playful contact, which in this species involves gentle nibbling of the posterior cheeks, was more frequently launched by the dominant than by the subordinate. This was not only true at the adult stage, but also at the juvenile stage, before dominance-subordination relationships were sharply polarized. Therefore, it would appear that in the relatively asocial hamster, the subordinates tend to avoid playful contact with dominants. This is markedly different to rats, where the subordinates actively seek out and engage dominants in play. This contrast further supports our hypothesis that subordinate male rats use play as a means of maintaining familiarity with dominants. © 1993 Wiley-Liss, Inc.     

Concomitant changes in classically conditioned heart rate and corneoretinal potential discrimination in the rabbit (Oryctolagus cuniculus)

Corneoretinal Potential (CRP) and heart rate changes were measured in a series of differential classical conditioning experiments in which the directionality of the heart rate response was related to (a) CRP acquisition, and (b) the certainty or uncertainty of the stimulus situation. The results suggested that heart rate decelerations were associated with stimuli that predict upcoming aversive events, while heart rate accelerations were associated with asymptotic CRP responding late in conditioning. These findings were interpreted in terms of (a) changes in general somatic activity, and (b) the cue properties associated with CSs which predict aversive events.