Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Agonistic Behavior”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1986

Agonistic behavior in food animals: review of research and techniques.

One type of social behavior--agonistic behavior--is commonly observed among food animals. Agonistic behaviors are those behaviors which cause, threaten to cause or seek to reduce physical damage. Agonistic behavior is comprised of threats, aggression and submission. While any one of these divisions of agonistic behavior may be observed alone, they usually are found, in sequence, from the start to the end of an interaction. Food animals may show interspecific or intraspecific agonistic behaviors. Interspecific agonistic behavior has not been extensively studied but it is agriculturally important because farm workers may become injured or killed by aggressive food animals. Types of intraspecific agonistic behavior are: when animals are brought together, intermale fighting, resource defense, inter-gender fighting and aberrant aggression. Common pitfalls in research on agonistic behavior among food animals include too few replicates to detect a biological difference, the assumptions of the analysis are not met, only aggression and not submission or other agonistic behavior components are measured, incomplete description of the behaviors are reported and a complete, quantitive ethogram did not form the basis for selecting behavioral measures.

Aggression↗
PubMed2003

Repeated exposure to social stress alters the development of agonistic behavior in male golden hamsters.

In male golden hamsters, exposure to social stress during puberty alters aggressive behavior. Interestingly, agonistic behavior undergoes two major transitions during puberty: a decline in attack frequency and a shift from play fighting to adult-like aggression. Based on previous observations, we developed an approach for characterizing offensive responses as play fighting or adult-like. The present studies had two aims. First, we validated our approach by looking at the development of attack types during puberty. Second, we looked at the effects of repeated social stress on the development of agonistic behavior by repeatedly exposing individuals to aggressive adults during puberty. In the first phase of the study, our results point to three different developmental periods. Initially, animals engage in agonistic behavior though attacks targeted at the face and cheeks. This period lasts from Postnatal Day 20 (P-20) to P-40 (early puberty). This phase corresponding to play fighting is followed by a transitional period characterized by attacks focused on the flanks (from P-40 to P-50, mid-puberty). Afterward, animals perform adult-like aggression characterized by attacks focused on the belly and rear. Our data also show that repeated exposure to aggressive adults has two separate effects on the development of agonistic behavior. Repeated social stress accelerated the onset of adult-like agonistic responses. Furthermore, attack frequency, while decreasing during puberty, remained at a higher level in early adulthood in stressed animals. These results show that repeated exposure to social stress during puberty alters the development of agonistic behavior both qualitatively and quantitatively.

Age Factors↗
PubMed1983

Grouping in Japanese quail. 1. Agonistic behavior during feeding.

Agonistic behavior in male Japanese quail, shown by aggressive pecking after feed restriction, was potentiated in unstable groups (a visitor bird moved to a new cage containing an unfamiliar resident each 24-hr period) but not in stable (a pair that was never changed once the birds were placed in cages) groups. The resident quail were more aggressive than either visitors or individuals of the stable groups. Ambivalent behavior (behavior characterized by an aggressive action followed immediately by a submissive posture) during feeding competition was observed in both the unstable and stable groupings. The ambivalent behavior appeared to be a conditioned response and was probably a result of the motivation to feed after a period of feed deprivation. During the experimental period the stable pairs of quail gained 28% of their initial body weight, but the resident and visitor quail, which were in the unstable grouping, gained only 15 and 13%, respectively. The differences in percentage weight gain were significant. Paired testes weights of the resident and visitor quail were significantly less than those of the stable birds.

Aggression↗
PubMed1995

Mating and agonistic behavior produce different patterns of Fos immunolabeling in the male Syrian hamster brain.

Previous work has shown that mating induces the expression of Fos protein within the chemosensory pathways of the male Syrian hamster brain. However, it is not known if this pattern of labeling is specific to mating or the result of social interactions in general. To determine the behavioral specificity of activation within these pathways, Fos immunostaining following mating was compared to that following agonistic behavior. Both mating and agonistic behavior are dependent upon chemosensory cues and gonadal steroids (reviewed in Refs 64, 65) and areas belonging to the olfactory and vomeronasal pathways process chemosensory and hormonal information (reviewed in Ref. 48). The results of this study demonstrate both similarities and differences in brain activation patterns following these two social behaviors. Agonistic behavior increased the number of Fos-immunoreactive neurons within most subdivisions of the medial amygdala, the anteromedial and posterointermediate bed nucleus of the stria terminalis, the ventrolateral septum and the ventral premammillary nucleus of the hypothalamus in a pattern comparable to that observed after mating. This pattern of activation common to mating and agonistic behavior may reflect an increase in an animal's general state of arousal during social interactions. In contrast, although mating and agonistic behavior both activated neurons within the caudal subdivision of the medial nucleus of the amygdala, the anterodorsal level of posteromedial bed nucleus of the stria terminalis and the paraventricular and ventromedial nuclei of the hypothalamus, in these areas either the distribution and/or number of Fos-immunoreactive neurons differed. In addition, agonistic behavior selectively activated neurons within the anterolateral bed nucleus of the stria terminalis, the anterior nucleus of the hypothalamus and the dorsal periaqueductal gray, whereas mating alone activated neurons within the posteroventral level of posteromedial bed nucleus of the stria terminalis and the medial preoptic area. No differences were found between dominant and subordinate males following agonistic behavior. These observations along with results from other laboratories suggest that mating and agonistic behavior activate distinct neural circuits.

Aggression↗
PubMed2003

Parallel changes in agonistic and non-agonistic behaviors during dominance hierarchy formation in crayfish.

Agonistic and non-agonistic behaviors were studied before, during, and after the formation of social status in crayfish. Differences in the expression of a non-agonistic behavior by dominant and subordinate crayfish developed in parallel with the differences in agonistic behaviors that indicate the animals' social status. An increase in burrowing behavior marked the ascendancy of the dominant animal, while an immediate suppression of burrowing paralleled the inhibition of aggressive behavior in the new subordinate. The strikingly similar changes in both agonistic and non-agonistic behaviors following the decision on status suggest related underlying neural mechanisms.

Aggression↗
PubMed1998

A description of the ontogeny of mouse agonistic behavior.

The development of agonistic behavior was characterized in outbred Swiss CD-1 male Mus domesticus. At weaning (postnatal day [PND] 21), mice were housed either individually or as male pairs. Social encounters were carried out between dyads of initially unfamiliar same-age and same-housing subjects every 3rd day, from PND 23 to 47. The majority of both offensive and defensive elements had their onset around PND 29. Overall, their expression increased around puberty (i.e., on PND 35), which also represented the peak of an inverted U-shaped profile for the frequency of the "ambivalent" tail rattling behavior. A stability of dominance-submission relationships over development appeared, and early short latencies to display either the first crouched posture (subordinate) or the first attack (dominant) turned out to be possible predictors of adult social status. Ongoing individual housing was associated with a greater expression and an earlier onset of fighting behavior.

Aging↗
PubMed2003

Field observations of intraspecific agonistic behavior of two crayfish species, Orconectes rusticus and Orconectes virilis, in different habitats.

Agonistic behavior is a fundamental aspect of ecological theories on resource acquisition and sexual selection. Crustaceans are exemplary models for agonistic behavior within the laboratory, but agonistic behavior in natural habitats is often neglected. Laboratory studies do not achieve the same ecological realism as field studies. In an attempt to connect laboratory results to field data and investigate how habitat structure affects agonistic interactions, the nocturnal behavior of two crayfish species was observed by scuba diving and snorkeling in two northern Michigan lakes. Intraspecific agonistic interactions were analyzed in three habitats: two food resources-macrophytes and detritus-and one sheltered habitat. The overall observations reinforce the concept that resources influence agonistic bouts. Fights in the presence of shelters were longer and more intense, suggesting that shelters have a higher perceived value than food resources. Fights in the presence of detritus patches had higher average intensities and ended with more tailflips away from an opponent, suggesting that detritus was a more valuable food resource than macrophytes. In addition, observations of aggressive behavior within a natural setting can add validity to laboratory studies. When fights in nature are compared with laboratory fights, those in nature are shorter, less intense, and less likely to end with a tailflip, but do show the fundamental fight dynamics associated with laboratory studies. Extrinsic and intrinsic factors affect intraspecific aggression in many ways, and both should always be recognized as having the potential to alter agonistic behavior.

Agonistic Behavior↗
PubMed1987

Psychotropic effects of adrenergic beta-blockers on agonistic behavior between resident and intruder mice.

The present study was conducted to investigate the effect of adrenergic beta-blockers on agonistic behavior in male mice, using quantitative ethological methods. Agonistic behavior was evoked using a resident-intruder paradigm. The following drugs were administered orally at four dose levels (vehicle, 5, 10 and 20 mg/kg) to either resident or intruder mice: dl-propranolol, practolol, d-propranolol, and l-propranolol. When the resident was treated with either dl-propranolol or l-propranolol, aggressive episodes (offensive sideways posture, attack bite, tail rattle) were suppressed significantly in a dose-dependent manner, whereas practolol and d-propranolol were ineffective. All treatments except the high dose of l-propranolol failed to affect the resident's solitary behavior (locomotion). When the intruder was treated with beta-blockers, agonistic behavior was not altered. Since practolol does not cross the blood-brain barrier, the differential suppression of agonistic behavior is due to the central action of beta-blockers. d-Propranolol does cross the blood-brain barrier but is devoid of beta-receptor blocking property; hence l-propranolol suppression of agonistic behavior implies inactivation of brain adrenergic beta-receptors. The findings seem to indicate that beta-blockers such as dl-propranolol and l-propranolol have a psychotropic action.

Adrenergic beta-Antagonists↗
PubMed1982

The inhibitory modulation of agonistic behavior in the rat brain: a review.

Neural regions which exercise an inhibitory influence on agonistic behavior are identified by the enhancement of agonistic behavior that follows their removal. The specific kinds of agonistic behaviors altered by each region are then examined. Increased reactivity to the experimenter and enhanced shock-induced fighting are produced by lesions of the region ventral to the anterior septum, the lateral septum, the medial hypothalamus, and the dorsal and median raphe nuclei. It is argued that the increased reactivity and shock-induced fighting correspond to an enhancement of defensive behavior. Mouse killing is induced by lesions of the anterior olfactory nucleus, the region ventral to the anterior septum, the lateral septum, the medial hypothalamus, the dorsal and median raphe nuclei, and the medial amygdala. Because the lesion-induced mouse killing is similar to that emitted by spontaneous mouse killers, it is argued that these regions normally exert an inhibitory control over predatory killing. The available evidence on social attack behavior has not convincingly identified regions exerting an inhibitory control over this dimension of behavior. Our conclusion is that separate brain systems exert an inhibitory control over defensive behavior, predatory killing, and social attack behavior. To a substantial extent, the regions modulating these behaviors appear to act independently of one another. The only neurotransmitter that is clearly active in these inhibitory systems is serotonin, and has only been directly implicated in the control of mouse killing by neurons originating in the dorsal and median raphe nuclei.

Aggression↗
PubMed1985

The cortico-medial amygdala in the central nervous system organization of agonistic behavior.

Previous studies suggested that the corticomedial amygdala is involved in agonistic behavior by affecting social learning processes. The present study shows that deficits in the avoidance of a dominant male rat conditioned by defeat were only observed after bilateral lesions restricted to the medial amygdala and not after destroying the cortical portion. These results are related to the specific afferent and efferent connections of the medial amygdala with other brain structures involved in the control of agonistic behavior. Within the corticomedial amygdala the medial amygdaloid nucleus was found to be a major recipient of afferents from the accessory olfactory bulb, but also a source of efferent projections to the ventrolateral aspects of the ventromedial hypothalamic nucleus and the ventral premammillary nucleus. A strong reciprocity exists in the connections between ventromedial hypothalamus and premammillary nuclei with the medial amygdala. The connections between the ventromedial hypothalamic and dorsal premammillary nucleus with the midbrain periaqueductal grey suggest an important role for the periaqueductal gray in the descending output in the anatomical substrate for agonistic behavior.

Aggression↗
PubMed2004

Agonistic behavior and dominance relationships in female Phayre's leaf monkeys -- preliminary results.

Socioecological theory suggests a link between the strength of competition for food/safety, rates of agonism, structure of dominance hierarchies, and dispersal among group-living females. This study presents preliminary data on agonistic behavior and dominance relationships for female Phayre's leaf monkeys (Trachypithecus phayrei), a species in which females routinely disperse. Behavioral observations were conducted on two groups (four adult females, and five adult females plus two juvenile females, respectively) at Phu Khieo Wildlife Sanctuary, northeast Thailand. Rates of agonistic behavior were analyzed from focal continuous recordings, while dominance hierarchies were constructed from all agonistic behaviors (focal and ad libitum sampling). Overall, female-female agonistic behaviors (aggression, submission, and displacements) occurred at a rate of < 0.25 interactions per hour. Agonistic interactions involving food occurred more frequently than expected based on feeding time. Females in both groups exhibited linear dominance hierarchies with some reversals, and possibly an age-inversed hierarchical structure in the larger group. The results fit well with previous results for colobine monkeys regarding frequency of interactions, displacements predominating agonistic behavior, and the possibility of an age-inversed hierarchy. The results contradict the suggested link between linearity of hierarchies and female philopatry. Future studies should consider the notion that female dispersal may coexist with linear dominance hierarchies.

Age Factors↗
PubMed1975

Theoretical review: a model of hormones and agonistic behavior.

A model of the interaction between endocrine function and agonistic responding was developed that incorporates three specific hypotheses about the relationship between hormones and agonistic behavior: (1) The baseline hormonal state of the organism contributes to the determination of whether, in what way, and how intensely the animal will react when it is exposed to appropriate environmental stimuli. (2) One function of the hormonal responses to environmental stimulation and behavioral experiences is to modify the continuing and future behavior of the individual in the same or similar situations. (3) Another function of these hormonal responses is to modify the individual's stimulus qualities so that other individuals' agonistic reactions to it will be modified. The data on hormones and agonistic behavior were reviewed in the context of this model, and some directions for future research were proposed.

Adrenal Glands↗
PubMed1983

d-Amphetamine in squirrel monkeys of different social status: effects on social and agonistic behavior, locomotion, and stereotypies.

The influences of social status on amphetamine-induced behavioral effects in squirrel monkeys were investigated. Social status was determined by constructing a sociogram. d-Amphetamine (0.3--1.0 mg/kg orally, 0.3 and 0.6 mg/kg IM) increased stereotyped head movements and reduced the time spent in the sitting posture in all monkeys (N = 25) regardless of sex, age, or social status. The high levels of locomotor activity in dominant and juvenile monkeys were decreased at higher amphetamine doses (0.6 mg/kg IM, 0.6 and 1.0 mg/kg orally), whereas the same doses increased locomotion in otherwise less active subdominant and submissive animals. Low doses of amphetamine (0.1, 0.3 mg/kg) decreased the incidence of agonistic behavior initiated by dominant monkeys, and higher doses (0.6, 1.0 mg/kg) caused these monkeys to change from predominant initiators of agonistic behavior into recipients. At 2 h after amphetamine administration (0.3 mg/kg IM), the high levels of locomotor behavior had returned to baseline, the social isolation began to disappear, and the disrupted agonistic behavior of dominant monkeys returned to control levels, yet the stereotyped head movements continued to occur with high frequency. In half of the monkeys, amphetamine produced a large increase in distress-like vocalizations. Amphetamine-mediated motor stereotypies may be mediated by mechanisms different than those responsible for agonistic behavior. The selective changes in agonistic behavior by dominant monkeys when challenged with amphetamine may reflect a status-related functional alteration of catecholaminergic processes upon which the drug acts.

Agonistic Behavior↗
PubMed1985

Steroid hormones and agonistic behavior in a cichlid teleost, Aequidens pulcher.

The effects of three steroid hormones on the agonistic behavior of female Aequidens pulcher have been evaluated. Testosterone, estradiol, and cortisol were tested using an immersion technique to minimize trauma, and we also examined metyrapone, a blocker of cortisol biosynthesis. Two different experimental protocols were employed, the first investigating agonistic interactions within groups of fish, and the second examining the responses of isolated fish to models and mirrors. Differences between replicates were small, and both protocols supported similar conclusions. Each of the three hormones produced a characteristically different spectrum of behaviors when compared to the controls. Testosterone increased agonistic behavior in all experimental situations, while estradiol had a generally opposite effect; this may reflect the natural modulation of behavior by hormones during the reproductive cycle of A. pulcher. Cortisol also had distinct behavioral effects; available evidence suggests that this steroid increases submissive components of agonistic behavior, and that observed increases in some aggressive components are an indirect consequence, dependent upon the feedback of social information received by each fish. Metyrapone treatment greatly reduced all agonistic behaviors, groups of fish forming shoals typical of juveniles. This was not reversed by replacement therapy with cortisol, which suggests that metyrapone affects behavior by an alternative, possibly toxic, mechanism.

Aggression↗
PubMed1982

Modulation of agonistic behavior by the dual olfactory system in male mice.

This study analyzed the effects of deafferentation of the main, vomeronasal or both olfactory systems on the agonistic behavior of male mice in response to unfamiliar male intruder mice. In every animal, regardless of the technique used, disruption of the vomeronasal system led to consistent reductions in agonistic behavior. All animals receiving bulbectomies, vomeronasal tract transections or a combined treatment of vomeronasal cuts and ZnSO4 nasal flush reliably suppressed agonistic responding toward the intruder. Animals treated with intranasal ZnSO4 alone or those receiving control procedures continued to respond to the intruders at rates similar to pretreatment. These results indicate that the vomeronasal system is directly involved in the perception of the male chemosignals modulating agonistic behavior and, therefore, is capable of modulating the male's response to these signals.

Aggression↗
PubMed1975

Agonistic behavior in the German cockroach, Blattella germanica.

Agonistic behavior in Blattella germanica is delineated with an emphasis on fighting techniques and population factors affecting aggressiveness. Male-male, male-female, and male-male encounters are not significantly different in either level of aggressiveness or frequency. Female-female carrying oothecae are, however, more aggressive than other female-female. The mean intensity of aggression increases as population density is increased, but number of contacts per individual per unit time remains constant. Defense of specific, territories does not occur and aggressive interactions are most common during the dark portion of the photocycle, when many of the cockroaches are observed to be foraging.

Aggression↗
PubMed1985

Age-sex differences in the expression of agonistic behavior in rhesus monkey (Macaca mulatta) groups.

Both age and sex influence rhesus monkey agonistic behavior. In intragroup episodes, submission was most frequent in juveniles, but aggression increased steadily with age, albeit much more sharply in females. As infants, males were more often involved in agonistic behavior than were females, but this sex difference reversed with age. A notable change in the frequency and forms of agonistic expression occurred in adolescent males. By the time they became adults, their participation in agonistic episodes was silent and brief and rarely involved biting. Adolescent males received high frequencies of aggressive responses, and this is hypothesized to account for the marked shift in adult male patterns of participation in intragroup agonistic interactions, as relative to females whose basic pattern of agonistic expression does not change with age.

Age Factors↗
PubMed1977

[Classical conditioning of agonistic behavior in the Syrian golden hamster (Mesocricetus auratus Waterhouse)].

Nine different reactions of unconditioned agonistic behavior of golden hamsters (Mesocricetus auratus Waterhouse) which could be elicited by an air blow (UCS) were classically conditioned at a sound of a xylophone (tone g), a previously neutral stimulus. Tone g (CS) was paired with UCS for a different number of trials/day. In all animals exposed to over 20 pairings/day components of the agonistic behavior were brought under the control of CS, but it was not possible to predict which one of the agonistic reactions would appear. Most of the animals generalized and also showed conditioned reactions (CR) when presenting tone c' instead of tone g. When utilizing a differential conditioning procedure the animals learned to discriminate between the different tones. Extinction of CR at tone g was reached after an individually different number of trials.

Acoustic Stimulation↗