光周期和气味信号对雄性布氏田鼠血浆睾酮含量的影响

Chemical signals provide important cues in social behavior of many mammalian speciesly, mediating sexual, aggressive, parental and spacing behavior, as well as influencing an animals internal hormonal milieu. Conspecific novel males substrate was given as individual odor stimulus to adult male Brandts voles(Microtus brandti) that left in individual cases in long\|photoperiod (LD) and short\|photoperiod (SD) resfectioely. The plasma testosterone of these male actors was mensurated by radioimmunoassay. The results indicated that plasma testosterone increased with the duration that the male vole was exposed to the odor of a novel male. Plasma testosterone concentration in LD males increased sigrificanily than those in SD males in 30 minutes.After 1 hour or 2 hours, exposed to the novel scents, the testosterone levels of LD males were higher than SD males, but didnt show significant difference. The results demonstrated that the chemical signals induced releasing of androgen and the increase of plasma testosterone of males voles exposed to novel conspecific odors was also influenced by the photoperiod. It suggest that the change of testosterone concentration would underlie the odor producing and odor preferences of Brandts vole.     

社会关系和性关系中的自我理毛行为

有很多观点解释了动物自我理毛的作用。例如,动物通过自我理毛可以清除在与附近的同种异性接触期间传播来的寄生虫,当嗅出同种异性的气味时也可能自我理毛,因为自我理毛是一种动物在逃避还是战斗之间所面临的进退两难选择时表现出来的改向行为。动物可以通过自我理毛缓解紧张,因而是一种缓解冲动的方式。在其它情况下,动物自我理毛可能表示对同种个体的反应,它们在不同场合下普遍存在自我理毛行为,表明这种行为有多种功能。因此,在这篇综述中,作者尽量避免自我理毛具有其它功能的争议,我们无意把自我理毛看成一种仅仅是对焦虑和紧张的反应、降低体温的机制,或者是一种护理体表的行为,我们也感到这种观点没有新意,这种有局限性的观点不支持自我理毛行为具有多种功能。我们在本文中更多关注的是自我理毛的特定背景,即当一个个体遇到同种个体的气味而出现的自我理毛行为[动物学报5l（5）：772-779,2005]。     

腋臭患者大汗腺中ApoD和AR的表达水平与气味强度间的关系

目的:明确大汗腺组织中ApoD和AR的表达水平与腋臭患者散发出气味间的关系,阐明两者在腋臭发病中的作用,为腋臭的临床治疗和干预奠定基础。方法:收集在我院整形外科就诊的腋臭病人腋下皮肤组织标本41例。手术前由3名医生共同判断患者腋下气味强度,按照能在≤1 m、≤3 m、≤5 m距离闻及气味把患者分为轻、中、重三组。随机抽取各组标本组织块进行RT-PCR检测,测定ApoD和AR在大汗腺组织中的含量。结果:根据气味强度判定标准,轻、中和重3组患者人数分别为:7人、11人和23人。按照AB 7500 Real-Time PCR系统分析结果所示ApoD相对表达量的等级与气味强度之间有线性关系(P0.05),ApoD相对表达量的等级随着气味强度的增加而升高;AR相对表达量的等级与气味强度之间有线性关系(P0.05),随着气味强度的增加而升高。结论:ApoD和AR的表达量与腋臭气味强度之间有着密切的联系。进一步证实AR可调节大汗腺组织ApoD的表达,为明确腋臭的发病机制提供了理论依据。     

食物种类对尖吻蝮幼蛇开口率的影响研究

目的观察投喂不同食物时尖吻蝮（Dienagkistrodon acutus）幼蛇的开口率,研究尖吻蝮幼蛇对食物的选择性,寻找最适宜的尖吻蝮幼蛇开口饵料;研究气味对尖吻蝮进食行为的影响,为人工配合饲料开发提供理论基础。方法将尖吻蝮幼蛇随机分组,在相同条件下对幼蛇进行饲养,分别使用泽蛙、幼体蟾蜍、SD大鼠的乳鼠、昆明种小鼠幼鼠、大麦虫、蚯蚓、中华蟋蟀、蟑螂对尖吻蝮幼蛇进行投喂,并统计开口率;在黑暗条件下投喂新鲜的死泽蛙和小鼠肉块,减少振感和食物与环境间温差对尖吻蝮的刺激,观察记录尖吻蝮的进食行为。结果尖吻蝮幼体开口率与食物种类有明显相关性,对蛙类和鼠类的开口率较高,而对昆虫类几乎无捕食。同时存在多种食物时尖吻蝮对食物有一定选择性,对运动较活跃和体温较高的食物选择性高。尖吻蝮可凭借气味寻找到食物并完成进食,对死食的进食率较活食低。结论 （1）泽蛙和幼鼠是尖吻蝮幼蛇的理想开口饵料;（2）尖吻蝮捕食过程中,除依赖视觉、震感、颊窝红外热感等感知食物外,还可通过气味来识别食物。     

Volatile exposure within the honeybee hive and its effect on olfactory discrimination

Honeybees of different ages and reproductive castes cohabit in the hive where they are exposed to many odors that might affect associative learning. Our aim was to analyze the role of odors pre-exposed as volatiles on appetitive learning in honeybees of different ages and search for their long-term effect both under natural and laboratory conditions. By evaluating memory acquisition and retention through a differential proboscis extension response conditioning, we found that hive-exposed odors offered as a reinforced conditioned stimulus during training promoted a learning-reduced effect [latent inhibition (LI)]. On the other hand, no effect was found when the non-reinforced conditioned stimulus was pre-exposed. The LI effect varied with the odor identity. However, only slight differences were found with the age of the bees. Exposure-conditioning intervals longer than 24 h did not show an LI effect unless the odor concentration was increased or exposure was prolonged. Our results show that pre-exposed volatiles could either reduce learning performance, if this odor is later associated with food, or be irrelevant in the case that alternative scented resources circulate within the colony. The differential effects found according to the olfactory exposure characteristics could strongly influence the propagation of chemosensory information within the hive.     

Linalool odor stimulation improves heat stress tolerance and decreases fat accumulation in nematodes

Aromatherapy uses plant essential oils and fragrant ingredients for relaxation, sleep assistance, and improvement of restlessness related to dementia. Certain aromatic substances increase the life span and stress tolerance of nematodes. We investigated effects of exposure to linalool, a linear chain monoterpenic alcohol that is present in the essential oils of many plants, and its optical isomer, l-linalool, in Caenorhabditis elegans. Nematodes were repelled by the odor of both linalool and l-linalool; however, linalool odor stimulation decreased fat accumulation and increased motility after thermal stress. Analysis of a gene-deficient mutant revealed that the DAF-16 insulin-signaling pathway, which is involved in heat stress tolerance, was enhanced by linalool treatment. Linalool stimulation increased the expression of downstream genes such as sod-3 and hsp-12.6 via DAF-16. We conclude that linalool odor induces a repelling behavior in nematodes, improves heat stress tolerance through the DAF-16 signaling pathway, and affects fat accumulation.     

哺乳动物嗅觉与母性识别

嗅觉通讯在陆生哺乳动物母性识别中具有重要作用。通过嗅觉信息,早熟性动物(有蹄类)产后早期能够迅速建立专一性的母性识别和母子联系,并具有母性识别的敏感期。在敏感期内,分娩经验、催产素及一氧化氮等神经递质的释放有助于这种识别和联系的形成。多项研究表明,晚熟性动物(如啮齿类)母性识别的形成主要基于断乳前母兽与幼仔共处获得的熟悉性,产后早期不能迅速形成专一性的母性识别和母子联系,母兽对亲生幼仔和非亲生幼仔的选择性哺育不完全取决于识别。实验方法及识别的判定标准对研究啮齿类的母性识别尤其重要。包括人类在内的灵长类母亲产后只通过嗅觉信息即可以对婴儿进行识别。在哺乳动物的母性识别中,妊娠和分娩过程会诱导嗅觉系统的高度可塑性,有利于促进母亲对幼体气味的学习,但硬连接(hard-wired)路径也可能参与母性识别。     

Testosterone and chemosensory detection in male Syrian hamster

Gonadal steroids stimulate both sexual motivation and performance. However, steroid facilitation of appetitive sexual behavior is poorly understood. The present study determined if castration impairs chemosensory detection in male hamsters. Chemosensory cues are the principal sensory modality to initiate mating in this species. We compared LiCl-induced conditioned taste avoidance to female hamster vaginal secretion (FHVS) in gonad-intact and castrated males. Following overnight water deprivation, males received FHVS for 15 min, followed by LiCl (2 ml of 0.15 M) or saline ip. The next day, fluid consumption in a two-bottle choice test was recorded for 5.5 h. Pairings were repeated 4×. Initially, discrimination of FHVS from estrous females (10 or 100 μg/ml) was compared with plain water. Subsequently, we determined if males could distinguish FHVS from Syrian vs. Djungarian females or from estrous vs. anestrous females. When 100 μg/ml FHVS was paired with saline, all gonad-intact and 86% of castrated males preferred FHVS over water. However, when 100 μg/ml FHVS was paired with LiCl, the preference was reversed: 12.5% of intact males and 25% of castrates preferred FHVS (P < 0.05 vs. saline pairing). When exposed to 10 μg/ml FHVS, neither gonad-intact nor castrated males expressed conditioned taste avoidance, suggesting that 10 μg/ml FHVS is below the threshold for detection. Comparing discrimination of FHVS from Syrian and Djungarian females, only castrated males developed a significant conditioned taste avoidance to Syrian FHVS paired with LiCl. While 71% of castrated males preferred Syrian FHVS after saline pairing, only 12.5% of castrates preferred Syrian FHVS after pairing with LiCl (P < 0.05). In gonad-intact males, 57% preferred Syrian FHVS after saline pairing, while 14% preferred Syrian FHVS following LiCl pairing (P > 0.05). Neither gonad-intact nor castrated males successfully discriminated between FHVS from estrous and anestrous females. These data demonstrate that castrated males perform as well as gonad-intact males in a test of LiCl-induced conditioned taste avoidance. Therefore, it is unlikely that steroids enhance detection of sexually relevant chemosensory cues.     

Mice (Mus musculus) lacking a vomeronasal organ can discriminate MHC-determined odortypes

Major histocompatibility complex (MHC) genes in mammals (H-2 in mice) play a major role in regulating immune function. They also bestow individuality in the form of a chemical signature or odortype. At present, the respective contributions of the olfactory epithelium and the vomeronasal organ (VNO) in the recognition of individual odortypes are not well defined. We examined a possible role for the VNO in the recognition of MHC odortypes in mice by first removing the organ (VNX) and then training the mice to distinguish the odors of two congenic strains of mice that differed only in their MHC type. C57BL/6J mice (bb at H-2) and C57BL/6J-H-2(k) (kk at H-2) provided urine for sensory testing. Eight VNX and six sham-operated mice were trained to make the discrimination. Neither the number of training trials-to-criterion nor the rate of learning differed significantly for VNX and sham-operated mice. We conclude that the VNO is not necessary for learning to discriminate between MHC odortypes.     

Electrophysiological evidence for detection and discrimination of pheromonal bile acids by the olfactory epithelium of female sea lampreys (<Emphasis Type="Italic">Petromyzon marinus</Emphasis>)

Electro-olfactograms were used to determine sensitivity and specificity of olfactory organs of female sea lampreys (Petromyzon marinus) to four bile acids: 3-keto petromyzonol sulfate and 3-keto allocholic acid from spermiating males and petromyzonol sulfate and allocholic acid from larvae. Spermiating male bile acids are thought to function as a mating pheromone and larval bile acids as a migratory pheromone. The response threshold was 10^–12 mol l^–1 for 3-keto petromyzonol sulfate and 10^–10 mol l^–1 for the other bile acids. At concentrations above 10^–9 mol l^–1, the sulfated bile acids showed almost identical potency, as did the non-sulfated bile acids. The two sulfated bile acids were more potent than the two non-sulfated ones. In addition, 3-keto petromyzonol sulfate and water conditioned with spermiating males induced similar concentration-response curves and response thresholds. Cross-adaptation experiments demonstrated that the sulfated and non-sulfated bile acids represent different odors to the olfactory epithelium of females. Further exploration revealed that 3-keto petromyzonol sulfate represents a different odor than petromyzonol sulfate, while 3-keto allocholic acid and allocholic acid represent the same odor. Results indicate that male-specific bile acids are potent and specific stimulants to the female olfactory organ, supporting the previous hypothesis that these bile acids function as a pheromone.Abbreviations 3kACA 3-keto allocholic acid - 3kPZS 3-keto petromyzonol sulfate - ACA allocholic acid - ANOVA analysis of variance - ELISA enzyme-linked immunosorbent assay - EOG electro-olfactogram - PIR percent initial response - PZS petromyzonol sulfate - SMW spermiating male washings