不同社会等级雄性根田鼠对自身和同性陌生气味的辨别

采用两两遭遇法确定雄性根田鼠的社会等级,然后以新鲜尿作气味源,在行为选择箱中观察不同社会等级雄性根田鼠对自身气味和非自身气味的行为响应模式,结果表明:种群中从属个体对自身尿液存在明显偏好,其对自身尿液的接近潜伏期显著短于非自身尿液,而访问时间、自我修饰频次都显著高于非自身尿液;种群中优势个体则优先访问非自身尿液,其对非自身尿液的访问时间、嗅舔时间、自我修饰及反标记均显著高于自身尿液;对非自身尿液,不同社会等级雄性个体之间存在明显不同的行为反应模式。这说明,不同社会等级雄性根田鼠具有自我识别的能力且模式不同,同时其对非自身尿气味响应模式的差异也与自身的社会等级有关。     

野生四川短尾鼩尿液中挥发性化学成分的分析

尿液在哺乳动物间的化学通讯中具有重要作用。本研究采用顶空固相微萃取-气质联用(HS-SPME-GC/MS)方法分析四川短尾鼩尿液中挥发性物质化学组成。结果表明,(1)通过检索国家标准与技术研究所质谱库,发现四川短尾鼩尿液中的化学成分主要为醛类、醇类、酮类、杂环、酯类、烷烃类、芳香烃类、含硫化合物、烯烃类、酚类等86种化合物,并且不同个体气味包含特有的挥发性化合物;(2)雌雄个体尿液中分别特有的挥发性化合物共计10种,其中雌性特有6种,雄性特有4种,表明四川短尾鼩尿液的化学成分存在性别差异。雌性的尿液中挥发性化合物76种,雄性只有33种,说明四川短尾鼩尿液中化学信号雌性多于雄性;(3)四川短尾鼩尿液中不同化学成分相对含量不同,同一组分在不同个体间相对含量存在差异。本研究有助于揭示四川短尾鼩尿液挥发性成分的化学通讯功能,并为引诱剂的研制提供基础资料。     

四川短尾鼩雄性信息素2-庚酮诱导雌性发情行为

本研究以四川短尾鼩Anourosorex squamipes为研究对象，首次对劳亚食虫目Eulipotyphla雄性尿液中2-庚酮的通讯功能进行报道。采用气相色谱-质谱联用分析去势雄性四川短尾鼩尿液中的挥发性成分，与正常雄性尿液进行对比，选取消失的化学成分中相对含量最高的作为候选信息素；采用阴道脱落细胞涂布验证候选信息素；将候选信息素对不同动情时期的雌性进行行为选择实验。结果表明：与正常雄性尿液中的132种挥发性化学成分对比，去势雄性尿液中有21种成分消失，其中，2-庚酮相对含量最高；与去势尿液和蒸馏水比较，在正常尿液和2-庚酮处理条件下，雌性的发情比例更高且时间更长；除潜伏期外的6项行为参数在不同动情时期均有显著/极显著的差异。这表明2-庚酮是四川短尾鼩的一种雄性信息素，对同种雌性具有化学通讯功能。本研究为四川短尾鼩信息素作为引诱剂应用于有害动物的防治提供了科学依据。     

雄性大熊猫对化学信息行为反应的年龄差异

化学通讯对哺乳动物的生存和繁殖起着重要作用。研究了雄性大熊猫(Ailuropoda melanoleuca)对同伴个体尿液气味行为反应的发育模式。结果显示,在成年雌性个体的尿液气味刺激下,雄性个体表现显著多的嗅闻行为和嗅闻/舔舐环境行为,但是嘶咬气味刺激物的行为明显减少。在雌性个体的尿液气味刺激下,不同年龄段的雄性个体行为表现不同,成年雄性个体表现较亚成年和幼年个体显著多的舔舐行为。此外,成年个体和亚成年个体均表现较多的嗅闻/舔舐环境行为,而幼年个体则无该行为表现。幼年个体较成年和亚成年个体表现显著多的气味涂抹行为,而且嘶咬气味刺激物的时间较亚成年个体显著多。幼年个体和亚成年个体对雌性和雄性个体尿液气味刺激的行为反应不存在显著差异。研究结果表明,雄性大熊猫对同种个体尿液中化学信息的行为反应呈现出年龄差异。     

雄性根田鼠的同胞竞争及其对同性个体的气味识别

采用两两互作实验并以尿标记来确定共居至成年的2雄性根田鼠同胞在行为竞争上的差异,之后在行为选择箱中分别观察它们对来自熟悉和陌生同性个体的新鲜尿气味的行为反应,以确定气味识别差异。结果表明：①雄性根田鼠两两互作时,尿标记的多少可以作为判断其社会等级的标准;②从属鼠对熟悉气味存在明显偏好,其对熟悉气味的访问时间、接近频次和自我修饰频次都显著高于陌生气味;③优势鼠则优先访问陌生气味,其对陌生气味的访问时间、嗅舔频次、嗅舔时间、自我修饰及反标记均显著高于熟悉气味;④对于陌生气味,优势鼠和从属鼠之间存在明显不同的行为反应模式。本实验结果提示,雄性根田鼠对同性尿气味识别的差异以及对陌生气味的行为反应,可能暗含着其领域防卫的信息。     

雄性大熊猫对化学信息行为反应的年龄差异

化学通讯对哺乳动物的生存和繁殖起着重要作用。研究了雄性大熊猫(Ailuropoda melanoleuca)对同伴个体尿液气味行为反应的发育模式。 结果显示，在成年雌性个体的尿液气味刺激下，雄性个体表现显著多的嗅闻行为和嗅闻/舔舐环境行为，但是嘶咬气味刺激物的行为明显减少。在雌性个体的尿液气味刺激下，不同年龄段的雄性个体行为表现不同，成年雄性个体表现较亚成年和幼年个体显著多的舔舐行为。此外，成年个体和亚成年个体均表现较多的嗅闻/舔舐环境行为，而幼年个体则无该行为表现。幼年个体较成年和亚成年个体表现显著多的气味涂抹行为，而且嘶咬气味刺激物的时间较亚成年个体显著多。幼年个体和亚成年个体对雌性和雄性个体尿液气味刺激的行为反应不存在显著差异。研究结果表明，雄性大熊猫对同种个体尿液中化学信息的行为反应呈现出年龄差异。     

非繁殖期成年雄性布氏田鼠对群体气体的辨别

本文研究了非繁殖期成年雄性布氏田鼠对陌生群本气味,本群体气体的社会探究行为和尿标记行为,探讨了布氏田鼠利用气味信号进行群体辨别的能力。在熟悉相的辨别实验中,雄鼠对陌生群体气味的社会探究和尿标记行为明显我于本群体气味和对照组,优势个体的探究和尿尿行为显著高于从属个体。实验结果表明,布氏田鼠具体对群体气味的辨别能力,在巢垫物中存在用于群体识别的化学通讯成分,优势鼠的气味标记可能性种内群体间的嗅觉通讯中     

非繁殖期成年雄性布氏四鼠对群体气味的辨别

本文研究了非繁殖期成年雄性布氏四鼠对陌生群体气味、本群体气味的社会探究行为和尿标记行为,探讨了布氏四鼠利用气味信号进行群体辨别的能力。在对熟悉相的辨别实验中,雄鼠对陌生群体气昧的社会探究和尿标记行为明显多于本群体气味和对照组,优势个体的探究和尿标记行为显著高于从属个体。实验结果表明：布氏田鼠具有对群体气味的辨别能力;在巢垫物中存在用于群体识别的化学通讯成分,优势鼠的气味标记可能在种内群体间的嗅觉通讯中起着重要的作用。     

雄性小鼠的社会优势地位、性吸引和信息素通讯

以前对小鼠的研究表明,优势雄鼠的尿液对雌性的吸引力比从属雄鼠大;同时,包皮腺分泌到尿液中的两个雄性信息素E-β-法尼烯和E, E- α-法尼烯含量相应升高,而尿液本身产生的两个雄性信息素成分--脱氢小蠹素和S-2-仲丁基- 二氢噻唑没有出现有效差异.为研究我们最近从小鼠(Mus musculus)包皮腺发现的两个雄性信息素16碳醇和16碳乙酸酯与雄性小鼠社会等级的关系, 我们将雄性小鼠两两配对饲养30天,让它们经历足够的社会争斗,建立起稳定的优势和从属关系.双项选择测试表明, 优势雄鼠的尿液对雌鼠的吸引比配对(组内)的从属鼠的强,优势雄鼠和来自另一配对组( 组间)的从属鼠尿液对雌鼠的吸引无差异.这说明优势和从属关系是相对于同一社群内的个体存在的.我们进一步用二氯甲烷分别萃取包皮腺分泌物和尿液,然后用气质联用(GC-MS )来定性和定量地分析组内优势和从属个体气味的化学组成的差异.结果表明:只有优势雄鼠的包皮腺产生的E-β-法尼烯和E, E-α-法尼烯含量一致高于从属雄鼠,而1 6碳醇和16碳乙酸酯以及尿液本身的脱氢小蠹素和丁基-二氢噻唑两个雄性信息素都无差异 .说明小鼠只利用包皮腺产生的两个分子量较小的雄性信息素浓度的相对升高传递社会优势地位的信息[动物学报 54(3):399-406,2008].     

雄性等级对布氏田鼠雌性选择的影响

利用监控录像以及特定行为记录的方法,研究了雄性等级对布氏田鼠气味选择和个体选择的影响。结果表明不论是气味选择还是个体选择,雌鼠动情状态不影响对雄鼠的选择频次,但是动情雌鼠在自我修饰行为频次上高于非动情雌鼠。此外,在气味和个体选择的优先权方面,动情雌鼠更多的优先选择优势雄鼠的气味和个体并与之交配,而非动情雌鼠更多的先选择从属雄鼠的气味和个体。总之,不论是气味选择还是个体选择,布氏田鼠不仅受到被选择雄鼠的地位影响,还与雌鼠的生理状态有关。     

Social context influences aggressive and courtship behavior in a cichlid fish

Social interactions require knowledge of the environment and status of others, which can be acquired indirectly by observing the behavior of others. When being observed, animals can also alter their signals based on who is watching. Here we observed how male cichlid fish (Astatotilapia burtoni) behave when being watched in two different contexts. In the first, we show that aggressive and courtship behaviors displayed by subordinate males depends critically on whether dominant males can see them, and in the second, we manipulated who was watching aggressive interactions and showed that dominant males will change their behavior depending on audience composition. In both cases, when a more dominant individual is out of view and the audience consists of more subordinate individuals, those males signal key social information to females by displaying courtship and dominant behaviors. In contrast, when a dominant male is present, males cease both aggression and courtship. These data suggest that males are keenly aware of their social environment and modulate their aggressive and courtship behaviors strategically for reproductive and social advantage.     

Differential Responses to Same and Opposite Sex Odors by Adult House Mice Are Associated with Anogenital Distance

Intrauterine position (IUP) of female and male fetuses in litter-bearing mammals can affect their physiology, morphology and behavior. The relationship between anogenital distance (AGD) and IUP was used as a bioassay for the degree of exposure of female and male fetuses to hormones in utero . Based on laboratory work in several rodent species, the following predictions were made for house mice ( Mus musculus domesticus ): (1) female mice should prefer odors from males with larger AGDs because such males are more aggressive, could protect more resources, and are better parents than males with smaller AGDs; (2) male mice should prefer odors from females with smaller AGDs because these females produce more offspring and are better parents than females with larger AGDs. We also tested the prediction that within sexes, mice should avoid odors from mice with larger AGDs because such mice are more aggressive. Responses to odors in traps were used to test these predictions for house mice living in outdoor enclosures using odor-baited traps. Both predictions were confirmed. Furthermore, mice of both sexes tended to avoid odor cues from individuals of the same sex that had larger AGDs, probably to decrease chances of an aggressive encounter that could result in injury.     

Behavioral coping strategies in a cichlid fish: the role of social status and acute stress response in direct and displaced aggression

The African cichlid fish, Astatotilapia burtoni, has a complex social system with a sophisticated social hierarchy that offers unique opportunities to understand how social rank and its physiological substrates relate to behavioral strategies. In A. burtoni, a small fraction of the males are dominant (T, territorial), as distinguished by being large, brightly colored, reproductively active, and aggressively defending territories. In contrast, the majority of males are non-dominant (NT, non-territorial), being smaller, drably colored, sexually immature, and typically schooling with females. The social system is regulated by aggressive interactions between males and behavioral responses to aggression can be direct or displaced with respect to the animal that acts. To determine whether direct and displaced behaviors are differentially exhibited by T and NT males, individuals were shown a video presentation of a dominant male displaying aggressively. Analysis of aggressive acts toward the video display and displaced activity toward a tank mate revealed that T males exhibited more direct behavior (toward the video display), while NT males engaged in more displaced behavior (toward tank mates). Because similar experiments with primates suggest that shifts in behavioral strategies are linked to changes in the stress response (as measured by circulating cortisol levels), we measured cortisol levels of T and NT males following exposure to the aggressive stimulus. Although in some animals subordinate males are reported to have higher cortisol levels, here we show that in A. burtoni the endocrine response to specific situations can vary considerably even among animals of the same status. Interestingly, NT males with intermediate cortisol levels showed more directed behavior while NT males with both high and low cortisol levels showed more displaced. This suggests an optimal physiological stress response in NT males that predisposes them to challenge aggressors perhaps making it more likely for them to ascend in status.     

黄山雄性短尾猴的拥抱行为

拥抱是非人灵长类动物特殊且重要的问候方式,常用于修复冲突后的个体间关系,但拥抱行为的影响因素及其社会功能仍需进一步阐明。本研究以栖息于安徽黄山的野生雄性短尾猴为研究对象,通过系统描述拥抱行为的类型、年龄组分布,分析拥抱行为的主要影响因素,并进一步探讨该行为的社会功能。结果显示：短尾猴的拥抱行为可分为无触摸生殖器、触摸生殖器和舔生殖器3种类型,其中无触摸生殖器和触摸生殖器类型最常见;3种类型的拥抱行为主要发生在非冲突环境下;随着年龄增加,拥抱行为的无触摸生殖器类型减少,触摸生殖器类型增加;成年个体的顺位越高,则接受拥抱越多,顺位提升会使个体接受拥抱的频次显著增加,顺位接近的个体拥抱发生频繁;拥抱发起的频次也与社会联系强度有正相关关系。本研究结果证实雄性短尾猴的拥抱行为具有表达顺位认知和增强社会联系的功能。     

Sex differences and similarities in the neuroendocrine regulation of social behavior in an African cichlid fish

An individual's position in a social hierarchy profoundly affects behavior and physiology through interactions with community members, yet little is known about how the brain contributes to status differences between and within the social states or sexes. We aimed to determine sex-specific attributes of social status by comparing circulating sex steroid hormones and neural gene expression of sex steroid receptors in dominant and subordinate male and female Astatotilapia burtoni, a highly social African cichlid fish. We found that testosterone and 17β-estradiol levels are higher in males regardless of status and dominant individuals regardless of sex. Progesterone was found to be higher in dominant individuals regardless of sex. Based on pharmacological manipulations in males and females, progesterone appears to be a common mechanism for promoting courtship in dominant individuals. We also examined expression of androgen receptors, estrogen receptor α, and the progesterone receptor in five brain regions that are important for social behavior. Most of the differences in brain sex steroid receptor expression were due to sex rather than status. Our results suggest that the parvocellular preoptic area is a core region for mediating sex differences through androgen and estrogen receptor expression, whereas the progesterone receptor may mediate sex and status behaviors in the putative homologs of the nucleus accumbens and ventromedial hypothalamus. Overall our results suggest sex differences and similarities in the regulation of social dominance by gonadal hormones and their receptors in the brain.     

Oxytocin and estrogen receptor alpha and beta knockout mice provide discriminably different odor cues in behavioral assays

Social behavior involves both the recognition and production of social cues. Mice with selective deletion (knockout) of either the gene for oxytocin (OT) or genes for the estrogen receptor (ER) -α or -β display impaired social recognition. In this study we demonstrate that these gene knockout mice also provide discriminably different social stimuli in behavioral assays. In an odor choice test, which is a measure of social interest and discrimination, outbred female Swiss-Webster mice discriminated the urine odors of male knockouts (KO: OTKO, αERKO, βERKO) from the odors of their wildtype littermates (WT: OTWT, αERWT, βERWT). Females showed marked initial choices of the urine odors of OTWT and βERWT males over those of OTKO and βERKO males, and αERKO males over αERWT males. The odors of OTKO and βERKO males also induced aversive, analgesic responses, with the odors of WTs having no significant effects. Odors of both the αERWT and αERKO males induced aversive, analgesic responses, with the odors of the WT inducing significantly greater analgesia. The odors of restraint stressed WT and KO males also elicited analgesia with, again, females displaying significantly greater responses to the odors of stressed OTKO and βERKO males than their WTs, and significantly lower analgesia to the odors of stressed αERKO than αERWT males. These findings show that the KO mice are discriminated from their WTs on the basis of odor and that the various KOs differ in the relative attractiveness/aversiveness of their odors. Therefore, in behavioral assays one causal route by which gene inactivation alters the social behavior of knockout mice may be mediated through the partners' modified responses to their odors.     

Social behavior of water bats (Myotis daubentonii, Chiroptera) in an open-air cage

The social behavior of Myotis daubentonii bats was studied in experimental groups kept in an openair cage. The repertoire of identification, aggressive, and friendly (integration) behaviors was described. Analysis of their frequencies showed that interactions between the animals were for the most part friendly (61.6%), while aggressive displays were rare (4.6%). Differences in behavior depending on sex and age were revealed: avoidance of contact and aggressive vocalization were observed significantly more frequently in young and adult males than in females. The bats in the experimental groups personally distinguished each other; in group 4, a two-level hierarchy was established (a dominant male vs. all other bats), which could be explained by specific conditions in the open-air cage.     

Sex-specific interactions between aggressive and sexual behavior in the rat: Effects of testosterone and progesterone

The influence of progesterone on sexual and aggressive behaviors during aggressive encounters was investigated in pairs of TP-treated male and female rats. Gonadectomized females, chronically injected with testosterone propionate (TP), showed low but consistent levels of feminine sexual behavior which alternated with aggression. Progesterone when given in addition to TP facilitated receptive and proceptive behaviors, but reduced levels of aggression. In TP-treated males, levels of aggression were the same as observed in TP-treated females. However, TP-treated males seldomly showed sexual behavior during aggressive encounters and additional treatment with progesterone did not affect their behavior. After the aggression tests, animals were tested in a social preference test in which an ovariectomized female cage mate and the opponent from the aggressive encounter served as incentives. Positive correlations between levels of aggression and social preference for an opponent were found in both sexes, although correlations only reached statistical significance when progesterone was given in addition to TP. These correlations were found in both sexes, despite the fact that group analysis revealed pronounced sex differences in social preference: males preferred to spend their time near ovariectomized female cage mates, whereas females divided their time equally among female cage mates and opponents.