Map-independent representation of an aggression-promoting social cue in the main olfactory pathway

While the olfactory system is required for proper social behaviors, the molecular basis for how social cues are detected via the main olfactory pathway of mammals is not well-characterized. Trimethylamine is a volatile, sex-specific odor found in adult male mouse urine that selectively activates main olfactory sensory neurons that express trace amine-associated receptor 5 (TAAR5). Here we show that trimethylamine, acting via TAAR5, elicits state-dependent attraction or aversion in male mice and drives inter-male aggression. Genetic knockout of TAAR5 significantly reduces aggression-related behaviors, while adding trimethylamine augments aggressive behavior towards juvenile males. We further show that transgenic expression of TAAR5 specifically in olfactory sensory neurons rescues aggressive behaviors in knockout mice, despite extensive remapping of TAAR5 projections to the olfactory bulb. Our results identify a specific main olfactory input that detects a prominent male-specific odor to induce inter-male aggression in a mammalian species and reveal that apparently innate behavioral responses are independent of patterned glomerular input to the olfactory bulb.

The Short-Term Effects of Gendered Primary Prevention Campaigns on Ambivalent Sexism and Beliefs about the Acceptability of Intimate Partner Violence

<p>This study aimed to explore the effects of portrayed gender roles in media campaigns on participants’ endorsement of sexism and approval of intimate partner violence (IPV) across two studies. Study one (N = 227) used a within-subjects experimental design and consisted of two parts separated by a one-week period. In part one, participants completed an online questionnaire that consisted of the Ambivalent Sexism Inventory and the Beliefs about Relationship Aggression Scale. In part two, participants randomly viewed a poster depicting heterosexual IPV or a non-violent control, then completed the measures. Study two (N = 380) aimed to replicate study one using a between-subjects experimental design, and followed the procedure of study one, part two. ANOVA revealed that participants approved of female to male violence significantly more than male to female violence, and this approval was more pronounced for males, indicating a chivalrous norm. Regression analyses revealed the more that females, but not males, endorsed benevolent sexism (BS), the less they approved of male aggression (no provocation). Contrarily, the more male and female participants endorsed BS, the more they approved of female aggression (total and infidelity). Hostile sexism was not related to approval. Across both studies, regression analyses revealed that exposure to a poster depicting male aggression did not significantly change participants’ approval of IPV or level of sexism. In contrast, it was found that participants who viewed a poster depicting female aggression approved of female aggression (total and infidelity) significantly less than participants who viewed a non-violent control poster, however, this was only observed in study two. Furthermore, regression analyses revealed that exposure to a poster depicting female aggression decreased participants’ endorsement of BS, with females decreasing the most relative to baseline, however, this was only observed in study one. The need for prevention campaigns to be informed by multifactorial frameworks, rather than single factor gendered theories, is discussed alongside other implications for policy and practice.</p>

The Short-Term Effects of Gendered Primary Prevention Campaigns on Ambivalent Sexism and Beliefs about the Acceptability of Intimate Partner Violence

<p>This study aimed to explore the effects of portrayed gender roles in media campaigns on participants’ endorsement of sexism and approval of intimate partner violence (IPV) across two studies. Study one (N = 227) used a within-subjects experimental design and consisted of two parts separated by a one-week period. In part one, participants completed an online questionnaire that consisted of the Ambivalent Sexism Inventory and the Beliefs about Relationship Aggression Scale. In part two, participants randomly viewed a poster depicting heterosexual IPV or a non-violent control, then completed the measures. Study two (N = 380) aimed to replicate study one using a between-subjects experimental design, and followed the procedure of study one, part two. ANOVA revealed that participants approved of female to male violence significantly more than male to female violence, and this approval was more pronounced for males, indicating a chivalrous norm. Regression analyses revealed the more that females, but not males, endorsed benevolent sexism (BS), the less they approved of male aggression (no provocation). Contrarily, the more male and female participants endorsed BS, the more they approved of female aggression (total and infidelity). Hostile sexism was not related to approval. Across both studies, regression analyses revealed that exposure to a poster depicting male aggression did not significantly change participants’ approval of IPV or level of sexism. In contrast, it was found that participants who viewed a poster depicting female aggression approved of female aggression (total and infidelity) significantly less than participants who viewed a non-violent control poster, however, this was only observed in study two. Furthermore, regression analyses revealed that exposure to a poster depicting female aggression decreased participants’ endorsement of BS, with females decreasing the most relative to baseline, however, this was only observed in study one. The need for prevention campaigns to be informed by multifactorial frameworks, rather than single factor gendered theories, is discussed alongside other implications for policy and practice.</p>

A resource-poor developmental diet reduces adult aggression in male Drosophila melanogaster

Aggressive behaviours occur throughout the animal kingdom and agonistic contests often govern access to resources. Nutrition experienced during development has the potential to influence aggressive behaviours in adults through effects on growth, energy budgets and an individual’s internal state. In particular, resource-poor developmental nutrition might decrease adult aggression by limiting growth and energy budgets, or alternatively might increase adult aggression by enhancing motivation to compete for resources. However, the direction of this relationship—and effects of developmental nutrition experienced by rivals—remains unknown in most species, limiting understanding of how early-life environments contribute to variation in aggression. We investigated these alternative hypotheses by assessing male-male aggression in adult fruit flies, Drosophila melanogaster, that developed on a low-, medium- or high-resource diet, manipulated via yeast content. We found that a low-resource developmental diet reduced the probability of aggressive lunges in adults, as well as threat displays against rivals that developed on a low-resource diet. These effects appeared to be independent of diet-related differences in body mass. Males performed relatively more aggression on a central food patch when facing rivals of a low-resource diet, suggesting that developmental diet affects aggressive interactions through social effects in addition to individual effects. Our finding that resource-poor developmental diets reduce male-male aggression in D. melanogaster is consistent with the idea that resource budgets mediate aggression and in a mass-independent manner. Our study improves understanding of the links between nutrition and aggression.Significance statementEarly-life nutrition can influence social behaviours in adults. Aggression is a widespread social behaviour with important consequences for fitness. Using the fruit fly, Drosophila melanogaster, we show that a poor developmental diet reduces aspects of adult aggressive behaviour in males. Furthermore, males perform more aggression near food patches when facing rivals of poor nutrition. This suggests that early-life nutrition affects aggressive interactions through social effects in addition to individual effects.

Body of Woman As A Site For Battle: A Critical Study of Sidhwa’s Ice-Candy Man

Partitioning of the subcontinent into Pakistan and India is a mega event in the history of South Asia that haunts the minds of the inhabitants because of the untold destruction and the atrocities inflicted on the migrants. The later generations come to know of the havocs carved on women's bodies mostly through stories of the victims or who witnessed molestation of women. In this connection, this article aims to critically analyze the novel Ice-Candy Man by Sidhwa which delineates the defilement of women at the periphery. The views of different feminist critics constitute the theoretical framework while Fairclough’s social discourse model serves as a methodological framework. For analysis, the technique of Content Analysis has been employed. The findings reveal that Sidhwa has caricatured the predicament of the women whose bodies became sites for male aggression as icons of the ethnic groups during the communal strives. They undergo physical and sexual furiousness of men before, during, and after the partition. Men dehumanized them to disgrace the opponents/the other. The novel may, further, be studied from psychoanalytical, cultural, and Marxist perspectives.

Gut microbiome modulates Drosophila aggression through octopamine signaling

Gut microbiome profoundly affects many aspects of host physiology and behaviors. Here we report that gut microbiome modulates aggressive behaviors in Drosophila. We found that germ-free males showed substantial decrease in inter-male aggression, which could be rescued by microbial re-colonization. These germ-free males are not as competitive as wild-type males for mating with females, although they displayed regular levels of locomotor and courtship behaviors. We further found that Drosophila microbiome interacted with diet during a critical developmental period for the proper expression of octopamine and manifestation of aggression in adult males. These findings provide insights into how gut microbiome modulates specific host behaviors through interaction with diet during development.

Flies getting filthy: The precopulatory mating behaviours of three mud-dwelling species of Australian Lispe (Diptera: Muscidae)

Lispe (Diptera: Muscidae) is a cosmopolitan genus of predatory flies that inhabit the muddy and sandy surrounds of water bodies. There are more than 163 described species worldwide, many of which are known to exhibit cursorial courtship displays which involve complex visual and vibratory signals. Despite the widespread distribution of these flies and their remarkable courtship displays, the biology and behaviour of most species are entirely unknown. Here, for the first time, we describe the pre-copulatory mating behaviours of three widespread and common Australian species: Lispe sydneyensis, Lispe albimaculata and Lispe xenochaeta. We demonstrate that all three species exhibit entirely unique courtship displays, consisting of complex behavioural repertoires. Importantly, we highlight intrasexual competition in L. sydneyensis, where males engage in competitive dances and combat. We also report female-male aggression in L. albimaculata and L. xenochaeta where females charge and display towards males. These novel mating systems provide unique opportunities to test ecological and evolutionary hypotheses.