Social rank and cortisol among female rhesus macaques(Macaca mulatta)

In animal societies,some stressful events can lead to higher levels of physiological stress.Such stressors,like social rank,also predict an increased vulnerability to an array of diseases.However,the physiological relationship between social rank and stress varies between different species,as well as within groups of a single species.For example,dominant individuals are more socially stressed at times,while at other times it is the subordinate ones who experience this stress.Together,these variations make it difficult to assess disease vulnerability as connected to social interactions.In order to learn more about how physiological rank relationships vary between groups of a single species,cortisol measurements from hair samples were used to evaluate the effects of dominance rank on long-term stress levels in despotic and less stringent female rhesus macaque hierarchal groups.In despotic groups,cortisol levels were found not to be correlated with social rank,but a negative correlation was found between social rank and cortisol levels in less stringent hierarchies.Low ranking monkeys in less stringent groups secreted elevated levels of cortisol compared to higher ranking animals.These data suggest that variations in the strictness of the dominance hierarchy are determining factors in rank related stress physiology.The further consideration of nonhuman primate social system diversity and the linear degree of their hierarchies may allow for the development of valid rank-related stress models that will help increase our understanding and guide the development of new therapeutics for diseases related to human socioeconomic status.

Social rank and cortisol among female rhesus macaques (Macaca mulatta)

In animal societies, some stressful events can lead to higher levels of physiological stress. Such stressors, like social rank, also predict an increased vulnerability to an array of diseases. However, the physiological relationship between social rank and stress varies between different species, as well as within groups of a single species. For example, dominant individuals are more socially stressed at times, while at other times it is the subordinate ones who experience this stress. Together, these variations make it difficult to assess disease vulnerability as connected to social interactions. In order to learn more about how physiological rank relationships vary between groups of a single species, cortisol measurements from hair samples were used to evaluate the effects of dominance rank on long-term stress levels in despotic and less stringent female rhesus macaque hierarchal groups. In despotic groups, cortisol levels were found not to be correlated with social rank, but a negative correlation was found between social rank and cortisol levels in less stringent hierarchies. Low ranking monkeys in less stringent groups secreted elevated levels of cortisol compared to higher ranking animals. These data suggest that variations in the strictness of the dominance hierarchy are determining factors in rank related stress physiology. The further consideration of nonhuman primate social system diversity and the linear degree of their hierarchies may allow for the development of valid rank-related stress models that will help increase our understanding and guide the development of new therapeutics for diseases related to human socioeconomic status.

Effect of early psychedelic use on social func⁃tion in adulthood

Psychedelic is one of psychoac⁃tive drug substances which leads to abnormali⁃ties in thinking,mood and sensory perception via the subtype of 5-HT receptor(5-HT2A receptor).Psychedelic is known to cause schizophrenia-like symptoms or worsen schizophrenia.Mean⁃while it causes abnormalities in neural synchroni⁃zation and oscillations.In recent years,with the prevalence of various new psychedelic drugs and the rising population of young addicts,the clinical effects of psychedelic have been highly concerned.Adolescence is an important period for the formation of neuroplasticity,and it is an important stage in the functional development and maturation of the central nervous system.However,it is currently unclear about the endur⁃ing effects of juvenile exposure to psychedelic on social behavior,and neural network function.OBJECTIVE The chronic exposure model of psy⁃chedelic(2CC-NBOMe,2CC)in rats was used to reveal the enduring effects on social behavior and neural network function in adulthood,which is intended to provide important reference infor⁃mation about the potential enduring effects and clinical applicability of psychedelic.METHODS Repeated exposure of normal saline in adoles⁃cence group(0.1 mL·kg-1,for 14 d),repeated exposure of 2CC group(0.1 mg·kg-1,for 14 d).The duration of adolescent administration was 35-48 d after birth.Adulthood means 9 weeks after birth.Behavioral and somatic neuroelectro⁃physiological experiments were performed 9-12 weeks after birth in the adolescent drug exposure group.RESULTS Psychedelic-exposed animals during adolescence showed a significant decline in social rank and an increase in social willingness.Coherence of theta waves(6-10 Hz)from the hippocampal CA1 to the orbital frontal cortex(Orb)was significantly reduced in the psy⁃chedelic-exposed animals compared to the con⁃trol animals.During the social task,the coher⁃ence of theta waves between CA1 and Orb was significantly reduced in the control animals,but not in the psychedelic-exposed animals.CON⁃CLUSION The altered social function caused by chronic psychedelic exposure during adoles⁃cence is associated with abnormal CA1-Orb theta wave coherence.

ComRank： Joint Weight Technique for the Identification of Influential Communities

Recently, the community analysis has seen enormous research advancements in the field of social networks. A large amount of the current studies put forward different models and algorithms about most influential people. However, there is little work to shed light on how to rank communities while considering their levels that are determined by the quality of their published contents. In this paper, we propose solution for measuring the influence of communities and ranking them by considering joint weight composed of internal and external influence of communities. To address this issue, we design a novel algorithm called Com Rank: a modification of Page Rank, which considers the joint weight in order to identify impact of each community and ranking them. We use real-world data trace in citation network and perform extensive experiments to evaluate our proposed algorithm. The comparative results depict significant improvements by our algorithm in community ranking due to the inclusion of proposed weighting feature.

Social dominance-related major urinary proteins and the regulatory mechanism in mice

Major urinary proteins(MUPs)have been proven to be non-volatile male pheromones in mice.Here,we aimed to elucidate the relationship between MUPs and dominance hierarchy,and the underlying molecular mechanisms.Dominance–submission relationship was established by chronic dyadic encountering.We found that at the urinary protein level and hepatic mRNA level,the expression of major MUPs,including Mup20,was enhanced in dominant males compared with subordinate males,indicating that MUPs might signal the social status of male mice.Meanwhile,the mRNA level of hepatic corticotropin releasing hormone receptor 2(CRHR2)was higher in subordinate male mice than in dominant male mice.Castration also enhanced the expression of CRHR2,but suppressed that of MUPs.CRHR2 agonist treatment reduced the expression of MUPs in liver.However,male social status failed to exert significant influence on serum testosterone and corticosterone as well as the mRNA expression of their receptors.These findings reveal that some MUPs,especially Mup20,might constitute potential dominance pheromones and could be downregulated by hepatic CRHR2,which is possibly independent of androgen or corticosterone systems.

Effects of social and climatic factors on birth sex ratio in Macaca mulatta in Mount Taihangshan area

Sex allocation theory predicts the optimal investment to male and female offspring.However,a biased sex ratio requires explanations as to why the deviation occurs.Rhesus macaque(Macaca mulatta)is the most widely distributed nonhuman primate species and the Taihangshan macaque(Macaca mulatta tcheliensis)occupies the northern limit of all rhesus macaque natural populations worldwide.We observed one macaque troop(Wangwu-1[WW-1])inhabiting Taihangshan Macaque National Nature Reserve and recorded all birth events and the sex of newborn macaques from 2004 to 2013.Our aim was to apply the Trivers–Willard hypothesis to this free-ranging rhesus macaque troop,and to understand the relationship between climatic parameters(precipitation and temperature)and birth sex ratio.We found that the total newborn macaques showed a female-biased sex ratio at birth in the WW-1 troop,but there were no significant biased birth sex ratios in all matriarchs and in high-ranking and middle-ranking matrilineal units.However,the low-ranking macaque matrilineal unit was significantly female-biased.Moreover,we found that the annual precipitation of the previous year was positively associated with the birth sex ratio,and there was an interactive effect of troop size and current winter temperature on the birth sex ratio.The underlying mechanisms for the effects of social and climatic factors on birth sex ratio could be complex,and we discuss several plausible explanations.

Male pheromones and their reception by females are co-adapted to affect mating success in two subspecies of brown rats

Pheromonal communication plays a key role in the sociosexual behavior of rodents.The coadaptation between pheromones and chemosensory systems has been well illustrated in insects but poorly investigated in rodents and other mammals.We aimed to investigate whether coadaptation between male pheromones and female reception might have occurred in brown rats Rattus norve-gicus.We recently reported that major urinary protein(MUP)pheromones are associated with male mating success in a brown rat subspecies,R.n.humiliatus(Rnh).Here,we discovered that MUPs were less polymorphic and occurred at much lower concentrations in males of a parapatric subspecies,R.n.caraco(Rnc),than in Rnh males,and found no association between pheromones and paternity success.Moreover,the observation of Rnc males that experienced chronic dyadic encounters and established dominance-submission relationships revealed that the dominant males achieved greater mating success than the subordinate males,but their MUP levels did not differ by social status.These findings suggest that male mating success in Rnc rats is related to social rank rather than to pheromone levels and that low concentration of MUPs might not be a reliable signal for mate choice in Rnc rats,which is different from the findings obtained in Rnh rats.In addition,compared with Rnh females,Rnc females exhibited reduced expression of pheromone receptor genes,and a lower number of vomeronasal receptor neurons were activated by MUP pheromones,which imply that the female chemosensory reception of pheromones might be structurally and functionally coadapted with male pheromone signals in brown rats.