Endocrine and behavioral differences between dominant and subordinate male house mice housed in pairs (original) (raw)
Related papers
Isolation versus grouping effects on adrenal and gonadal function in albino mice I. The male
General and Comparative Endocrinology, 1971
There is much conflicting evidence on the effect of isolation as opposed to grouping on adrenal function in mice. A series of experiments wits carried out to compare isolated and grouped (16) male mice, which had been differentially housed at different ages (at weaning or at 4 months of age), for different lengths of time (for 13 days or 10 weeks) and with and without mating experience. The parameters studied included body and various organ weights, plasma levels of corticosterone and electrolytes and aggressiveness in a test situation. Isolated male mice had lower adrenal weights than their grouped counterparts and their plasma levels of corticosterone, both basal and after 5 min of ether stress, were usually lower when compared with values for grouped males. Also isolated mice usually had higher plasma potassium ion concentrations following ether stress. Single animals had heavier relative weights for the ventral prostate and exhibited higher aggression test scores than the grouped mice. It is concluded that isolation increases pituitary/gonadal function and results in decreased activity of the adrenal cortex. Whether the adrenal changes are partly induced by the elevated androgen levels or are due to the absence of social stress No evidence of an isolation stress was which results from fighting is uncertain obtained.
Sex differences in hormonal responses to social conflict in the monogamous California mouse
Hormones and Behavior, 2010
Monogamous species are usually considered to be less likely to exhibit sex differences in behavior or brain structure. Most previous studies examining sex differences in stress hormone responses have used relatively sexually dimorphic species such as rats. We examined the stress hormone responses of monogamous California mice (Peromyscus californicus) to resident-intruder tests. We also tested males and females under different photoperiods, because photoperiod has been shown to affect both aggression and stress hormone responses. Females, but not males showed a significant increase in corticosterone levels immediately following a resident-intruder test. Males but not females showed elevated corticosterone levels under short days. Females tested in aggression tests also showed a significant increase in plasma oxytocin levels, but only when housed in long days. This was consistent with our observation that females but not males had more oxytocin positive cells in the paraventricular nucleus (PVN) when housed under long days. Our data show that sex differences in glucocorticoid responses identified in other rodents are present in a monogamous species.
Behavioural comparisons of isolated, dominant and subordinate mice
Behavioural Processes, 1979
The study examines the suggestion that isolated male mice act in a similar way to dominant males. Behaviours of isolated, dominant and subordinate mice were compared in an open-field, emergence test, activity monitor and aggression test. In a number of ways the behaviour of both isolates and dominants differed from subordinates. Subordinates were more active on the first day in the open-field, but they habituated relatively quickly. In contrast, both the isolates and dominants were initially relatively inactive, but reacted to a novel situation for longer. There were, however, no circadian variations in activity in the three categories of mice. Unlike the subordinates, both dominants and isolates displayed aggression towards male mice; these last two categories of mice also had heavier sex accessory glands. It was concluded that the behaviour of isolated and dominant mice is very similar, at least under the conditions of this experiment.
2014
Violence is a serious public health problem and has a high impact on the quality of life of individuals across societies. Evolutionary, genetic, environmental, and cultural factors are closely interconnected as morbid causes. Animal models can be an important tool in the study of aggression. Regrouped Swiss Webster mice were selected based on mobility profile (Hypo, Normal; Hyper), which was defined by the tail suspension test. Our results demonstrate that Hyper mice (anxiety-like behavior) were more aggressive and violent than the other two categories, indicated by a pattern of aggressive behavior with a score 4+ in relation to score 1+ of Normal category. Hyper group, showed a decrease in total testosterone levels (-32.5% in relation to Norm group) and an increase in progesterone levels (+57.6% compared with the Norm group). We also observed a decrease in the weight of the testicles, the seminiferous tubules, Leydig and diploid spermatogenic cells number in hyper aggressive animal...
Effects of prior housing on endocrine responses to differential caging in male TO-strain mice
Physiological Psychology, 1979
Two possible reasons which may account for the inconsistent reports of adrenal and gonadal functioning in individually and group-housed mice were studied. The influence of the prior housing condition on the response to differential housing was examined. Continuously grouped or isolated mice were found to have lower corticosterone levels than those paired then isolated or isolated then paired. The influence of rehousing was apparent 32 days afterwards. The results support the suggestion that changing the housing condition of mice is stressful. The possible effect on endocrine function of different numbers of dominant and subordinate mice in different sized groups was examined. The findings did not support previous work which had found a similarity between dominant and isolated mice: it seems that the conditions used in particular experiments are critical to the results.
Proceedings. Biological sciences / The Royal Society, 1998
Naked mole-rat colonies are societies with a high reproductive skew, breeding being restricted to one dominant female (the`queen') and 1^3 males. Other colony members of both sexes are reproductively suppressed. Experimental removal of breeding males allowed us to investigate the relationship between urinary testosterone and cortisol, dominance rank, and male reproductive status. Dominance rank was strongly correlated with body weight, age, and urinary testosterone titres in males. No relationship between urinary cortisol levels and male reproductive status or dominance was found. Breeding males were among the highest-ranking, heaviest and oldest males in their respective colonies, and were succeeded by other high-ranking, large, old colony males. In contrast to females, no evidence of competition over breeding status was observed among males. Male^male agonism was low both before and after removal of breeders and mate guarding was not observed. The lower reproductive skew for males compared with female skew or queen control over male reproduction may explain why males compete less strongly than females over breeding status after removal of same-sexed breeders.
Paternal behavior increases testosterone levels in offspring of the California mouse
Hormones and Behavior, 2010
Paternal care during early development influences pup survivorship in the monogamous and biparental California mouse, Peromyscus californicus. Moreover, paternal pup retrievals impact development of adult offspring aggression and the neuropeptide vasopressin, yet little is known about the underlying mechanisms of these developmental changes. Because testosterone can increase arginine vasopressin and aggression, we hypothesized that paternal pup retrievals increase testosterone levels in prepubertal male P. californicus pups. Male pups were assigned to one of three groups: hormonal baseline, nonretrieval control, or retrieval. On postnatal days 18-21, all pups and the mother were removed from the cage, and the focal male pup was placed either outside of the nest to elicit paternal retrievals (retrieval group) or in the nest to discourage paternal retrievals (nonretrieval group). Testosterone was elevated at 45-min, but not 90-min, postmanipulation in retrieved compared to nonretrieved pups. Moreover, there was a significant positive correlation between pup retrievals and testosterone in the 45-min group. This rapid testosterone rise in response to paternal retrievals may facilitate an increase in aggression and vasopressin in adult offspring. Therefore, this period of development previously viewed as hormonally quiescent may be more active in response to paternal behavior than previously thought.
Hormones and Behavior, 2001
Testosterone (T) mediates a trade-off, or negative correlation, between paternal behavior and aggression in several seasonally breeding avian species. However, the presence or absence of a T-mediated trade-off in mammals has received less attention. We examined the relationship between paternal behavior and territorial aggression in the biparental California mouse, Peromyscus californicus. In contrast to seasonally breeding birds, T maintains paternal behavior in this year-round territorial species. Castration reduced paternal behavior, whereas T replacement maintained high levels of paternal behavior. We hypothesize that T is aromatized in the brain to estradiol, which in turn stimulates paternal behavior. In contrast to paternal behavior, aggressive behavior was not reduced by castration. Interestingly, only sham males showed an increase in aggression across three aggression tests, while no change was detected in castrated or T-replacement males. Overall, trade-offs between aggression and paternal behavior do not appear to occur in this species. Measures of paternal behavior and aggression in a correlational experiment were actually positively correlated. Our data suggest that it may be worth reexamining the role that T plays in regulating mammalian paternal behavior.
Psychoneuroendocrinology
Social environment and parental state affect stress responses in mammals, but their impact may depend on the social and reproductive strategy of the species. The influences of cohabitation with a male or female conspecific, and the birth of offspring, on the physiological and endocrine responses to chronic variable stress were studied in the monogamous and biparental California mouse (Peromyscus californicus). Adult male California mice were housed either with a male cage mate (virgin males, VM), a female cage mate (pair-bonded males, PBM), or a female cage mate and their first newborn litter (new fathers, NF). VM, PBM and NF underwent a 7-day chronic variable stress paradigm (CVS, three stressors per day at semi-random times, n=7-8 per housing condition). Compared to control males (CON, n=6-7 per housing condition), CVS caused loss of body mass, increased basal plasma corticosterone concentrations, and increased basal expression of arginine vasopressin (AVP) mRNA in the paraventric...