Quantitative chromatographic profiling of odours associated with dominance in male laboratory mice (original) (raw)
Related papers
Chronic exposure of cat odor enhances aggression, urinary attractiveness and sex pheromones of mice
Journal of Ethology, 2008
To test whether predator odor exposure negatively affects the behavior of prey, we exposed three groups of male house mice (Mus musculus) to the odors of cat (Felis catus) urine, rabbit (Oryctolagus cuniculus) urine and water (control), respectively, for consecutive 58 days and investigated how the treatments affected the response, aggressiveness, dominance, urinary attractiveness to females and pheromone composition of male mice. Compared to mice exposed to rabbit urine or water, those exposed to cat odor did not show any response habituation to the cat odor and became more aggressive, increased mark urine production and were more attractive to females when the latter were tested with their urine. Furthermore, gas chromatography coupled with mass spectrometry analysis revealed coincident elevations of the well-known male pheromones, E,E-a-farnesene, E-b-farnesene, R,R-dehydroexo-brevicomin or S-2-sec-butyl-dihydrothiazole. In addition, rabbit urine exposure increased urinary attractiveness to females and pheromonal levels of the males in comparison with the mice exposed to water. This could be related to olfactory enrichment of heterospecific chemosignals, suggesting that predator odors were more beneficial. In light of these anti-intuitional findings in the chemical interaction between cats and mice, we conclude that predator odor affects prey more profoundly than previously believed and that its impact may not always be negative.
Hormones and Behavior, 2004
Half a century has passed since the first report of the influence of odors on mice. Odors are known to influence behavior (signaling effect) and affect the physiology (primer effect) of mice. This review focuses on summarizing the primer effects found so far in female and male mice. Odors from conspecifics of the opposite sex had the tendency to enhance reproductive activities, whereas odors from conspecifics of the same sex diminish them. Only 2,5-dimethylpyrazine, one of the odor components identified in group-housed females, has been reported to have a suppressive influence on both males and females by lowering reproductive activities. Studies showed progress from the discovery of phenomena to the identification of odor components that cause such changes in reproductive organs and related neuroendocrinological changes. Compared to studies on the mechanisms of primer effects in females, the mechanisms in males are not yet clarified, and detailed studies on effects on the reproductive organs are still in primitive stages especially for males. Hypotheses on the influence of changes in the concentration of testosterone, estrogen, and prolactin on spermatogenesis and sperm maturation after exposure to odors are discussed.
Effects of novel odours on the mating behaviour in mice
The aim of this study was to examine whether and how different odorants placed on the bodies of female mice, but having no reward value for the males, affect courtship and mating behaviour of male mice towards females in oestrus and thus emitting female pheromones. In this manner, certain consequences of concurrent activation of the main olfactory system and the vomeronasal system were investigated. Four different odorants (white musk, lavender, peppermint and valerian) were used for swabbing female mice in oestrus. Using a total of 160 sexually naive outbred mice of both sexes, divided for each of 4 odorants into controls (not swabbed with odorant) and two experimental groups, in the experimental group I the females observed previously as controls were swabbed with one of the 4 odorants, while in the experimental group II, new naive females were swabbed with one of the 4 odorants. The females were observed in individual cages for 30 min. each, together with a respective sexually naive male. The latency between introduction of a male into a cage with a previously swabbed female and initiation of courtship and mating behaviours by males (sniffing, circling, misdirected mounting, copulation failures, successful copulation) was recorded. Latency to the occurrence of all sexual behaviours was significantly longer in experimental groups compared to controls. Latency to initiation of courtship behaviour, especially sniffing and circling, was shorter towards females swabbed with peppermint odour than for other odorants, indicating no aversion to this odour. However, the peppermint odour completely inhibited copulation. It is concluded that alien volatile odours with no reward value nevertheless exert differentiated suppressing effects on female mice pheromones inducing courtship and mating behaviour. Thus, it is hypothesized that the activation of the main olfactory system suppresses the accessory vomeronasal system.
THE SMELL OF MEN AND WOMEN AS A FACTOR INFLUENCING THE BEHAVIOR OF LABORATORY RATS
Academia Letters, 2021
The results of behavioral tests of laboratory animals are highly variable. Even within the same laboratory, the results of the same test can differ significantly. We tested the effect of the human smell-male and female-on the behavior of male Wistar rats, because we know the great role of chemical communication in the biology of all animals, and rats in particular. The smell donors were clinically healthy non-smoking, low-alcohol-consuming volunteers aged 20-21 years-four men, and four women in the luteal phase of the menstrual cycle. They wore cotton socks and T-shirt at night, which they sealed in plastic bags in the morning. The animals were tested on the same day. One sock from each donor was placed in containers and presented to the rats. Two series of experiments were conducted. Before conducting experiments with animals, the handling procedure was performed for two weeks-a daily pickup by the experimenter. In the first experiment (n=20), the rats were tested during five minutes in the elevated zero maze. Smell samples were placed in the center of the ring. First, we tested naive animals, after 20 days-in the presence of a male smell, and after another 20 days-in the presence of a female smell. Testing was carried out from 13 to 17 hours. The presence of human odors during testing increased the rats' anxiety. A male smell had a greater effect than a female smell. In the second experiment (n=29), the delayed effect of exposure to human odors was studied. To do this, plastic perforated containers with fabric were placed in home cages for one
Chemical Senses, 2010
Mice recognize other mice by identifying chemicals that confer a molecular signature to urinary marks. Such molecules may be involved in species recognition, and previous behavioral studies have related divergence of sexual preference between 2 subspecies of the house mouse (Mus musculus musculus and Mus musculus domesticus) to urinary odors. To characterize the differences between odors of males of the 2 subspecies and their first-generation offspring, the urinary volatile molecules were examined via gas chromatography coupled to mass spectrometry. Seven molecules were present in the samples from mice of at least one group. Their quantity varied among groups: M. m. domesticus showed a quantitatively richer panel of odorants in their urine when compared with M. m. musculus. The hybrids showed a more complex picture that was not directly related to one or the other parental subspecies. These quantitative differences may contribute to the specificity of the odorant bouquet of the 2 subspecies.
Social features of scent-donor mice modulate scent marking of C57BL/6J recipient males
Behavioural Brain Research, 2009
Territorial male mice can form familiarity-dependent amicable relationships, suggesting that they manage their territorial aggressiveness based on individual recognition, which may be mediated by olfactory signals. The present study demonstrated modulatory effect of odorant cues from mice of different social/housing groups on territorial scent marking by C57BL/6J males. Pair-housed males deposited few scent marks in a novel situation without mouse odors, while singly-housed males marked more in the same situation (Experiment 1). However, when confronted by a conspecific, singly-housed males made fewer marks to pair-housed than to singly-housed stimulus males, while pair-housed males showed few marks to either stimulus animal (Experiment 2). Reduction in scent marking in singly-housed males was also seen on exposure to urine scent alone from a pair-housed male, indicating that the inhibitory cue is mediated by urinary odor (Experiment 3). This inhibitory odor was effective even when singly-housed males were placed in a no-odor environment following exposure to soiled bedding used by pair-housed males (Experiment 4). When singly-housed males were exposed to scent from subordinate males, they showed less marking than when the stimulus scent was from dominants or singly-housed males (Experiment 5). Scent marking was not influenced by the total amount of urine scent marks deposited on the substrates (Experiment 6), suggesting that it is a particular component in urinary odor rather than the magnitude of the odor, that plays a significant role in recipient behavior. Together, these experiments indicate that conspecific male odor signals modulate territorial scent marking behavior in mice.
Regulation of volatile and non-volatile pheromone attractants depends upon male social status
Scientific Reports, 2019
We investigated the regulation of chemical signals of house mice living in seminatural social conditions. We found that male mice more than doubled the excretion of major urinary proteins (MUPs) after they acquired a territory and become socially dominant. MUPs bind and stabilize the release of volatile pheromone ligands, and some MUPs exhibit pheromonal properties themselves. We conducted olfactory assays and found that female mice were more attracted to the scent of dominant than subordinate males when they were in estrus. Yet, when male status was controlled, females were not attracted to urine with high MUP concentration, despite being comparable to levels of dominant males. To determine which compounds influence female attraction, we conducted additional analyses and found that dominant males differentially upregulated the excretion of particular MUPs, including the pheromone MUP20 (darcin), and a volatile pheromone that influences female reproductive physiology and behavior. Our findings show that once male house mice become territorial and socially dominant, they upregulate the amount and types of excreted MUPs, which increases the intensities of volatiles and the attractiveness of their urinary scent to sexually receptive females. House mice (Mus musculus) excrete large quantities of major urinary proteins (MUPs) that bind and transport hydrophobic ligands, including several volatile pheromones 1-3. Upon excretion, MUPs slow down the release of volatiles from scent marks 4-8 , which may prolong their attraction and influence on conspecifics. MUPs are often suggested to show high individual diversity and thereby mediate individual and kin recognition 9,10. They are encoded by 21 paralogous loci, but MUP genes are highly homologous 11,12 and no individual variation has been detected in wild populations 13. Interestingly, MUP excretion is sexually dimorphic 5,14,15 , under endocrine control 16-18 , and dynamically regulated 19 depending upon health 20-22 , nutritional status 23 , and social interactions 24,25. Our aims here were to test whether house mice regulate the excretion of MUPs or volatile pheromone ligands depending upon their social status, and whether such regulation influences the attractiveness of their odor to potential mates 24. Male house mice are territorial and much evidence indicates that intra-and inter-sexual selection are mediated by chemosensory signals. Dominant territorial males scent mark their territories, and males deposit more scent-marks after winning an agonistic encounter compared to losers (winners are commonly labeled as 'dominants' and losers as 'subordinates') 26-28. Females are attracted to male urinary scent 29-31 and especially to the scent of 'dominant' males 32-35. Male reproductive success correlates with scent-marking when male social status is controlled and females are free to select their mates 36. Male urine also has priming effects on female reproductive physiology (accelerating puberty, synchronizing estrus, and blocking pregnancy 37), and especially if males are socially 'dominant' 38. Several volatile odor compounds (VOCs) have been identified as sexual pheromones (eliciting sexual attraction, priming effects, or both), including αand βfarnesene 39 , 2-sec-Butyl-4, 5-dihydrothiazole (SBT), 3, 4-dehydro-exo-brevicomin (DHB), and 6-hydroxy-6-methyl-3-heptanone (HMH 40), though not in all strains 41. Exposure to a combination of male pheromones (SBT, DHB, and HMH) induces female olfactory
Indian journal of experimental biology, 2014
The behavioural assays were carried out in a Y-maze wherein intact, castrated and testosterone-treated male mice were exposed to oestrus and non-oestrus urine samples. The intact male mice investigated more frequently and spent more time in the Y-maze arm with oestrus urine than in that with non-oestrus urine. In contrast, the castrated mice were not attracted to oestrus urine, whereas testosterone-treated mice showed preference for oestrus urine. The rate of self-grooming was higher in intact males in case of exposure to oestrus urine while the rate was lower with respect to non-oestrus urine. However, castrated mice exhibited less self-grooming behaviour which was partially restored by testosterone treatment. The results suggest that self-grooming behaviour is an indicator of detection and discrimination of oestrus by males, and supports the androgen role in male chemosensory ability to discriminate between oestrus and non-oestrus female odours.
Chemical communication plays an integral role in social behavior by facilitating social encounters, allowing for the evaluation of social partners, defining territories and advertising information such as species and sex. Odors provide information about the social environment for rodents and other mammals; however, studies identifying chemical compounds and their functions have thus far focused primarily on a few species. In addition, considerably less attention has been focused on how environmental factors and behavioral context alter these compounds during periods of reproductive quiescence. We examined the effects of photoperiod and social context on chemical communication in the seasonally breeding Siberian hamster which displays modest territorial aggression during long “summer-like” days, but increased aggression in short “winter-like” days. We collected urine samples from long- and short-day male hamsters to investigate how photoperiod and subsequent changes in reproductive phenotype alter urinary volatile compound profiles. Next, we identified changes in urinary compounds before and after an aggressive encounter. Male hamsters exhibited a diverse urinary profile across photoperiods; however, long-day reproductive males showed higher levels of individual compounds when compared to short-day non-reproductive males. In addition, individual compounds were altered following an aggressive encounter; some changed only in long days whereas others changed regardless of photoperiod. Further, aggression and circulating levels of testosterone were positively correlated with urinary compounds in long-, but not short-day males. These findings suggest both photoperiod- and aggression-specific physiological regulation of urinary compounds in this species and contribute to a greater understanding of chemical communication more broadly.
Scent marking behavior in male C57BL/6J mice: Sexual and developmental determination
Behavioural Brain Research, 2007
The present study investigated urinary scent marking behavior in male C57BL/6J (C57) mice as olfactory social signaling. In Experiment 1, when compared scent marking toward adult males, C57 males showed substantial scent marking toward CD-1 males and even toward the odor alone of CD-1 males, but not toward C57 males. Experiment 2 explored scent marking in C57 males of different ages to males and females, and juveniles and adults of the same strain. C57 males deposited more marks than control conditions only toward an adult C57 female when tested at 100 days of age, but not at 60 days of age. Development of urine marking behavior was investigated in C57 males at the ages of 30, 60, 90, and 120 days in Experiment 3. When tested alone (control) or confronted with a C57 male, C57 males showed diminished scent marks throughout development. Compared to controls, marking toward a CD-1 male increased after the age of 60 days, while marks toward an adult female showed significant increases after the age of 90 days. This difference in scent marking depending on the sex of the stimulus animal is likely to be associated with development of sexual behavior, in which males need to set up territories against other males prior to advertising to females. Although highly inbred strains have similar odor components, C57 males are able to detect and deposit urine marks after puberty as social communication depending on age, sex, and genetic differences in the opponents.