A functional circuit underlying male sexual behaviour in the female mouse brain

In mice, pheromone detection is mediated by the vomeronasal organ and the main olfactory epithelium. Male mice that are deficient for Trpc2, an ion channel specifically expressed in VNO neurons and essential for VNO sensory transduction, are impaired in sex discrimination and male-male aggression. We report here that Trpc2-/- female mice show a reduction in female-specific behaviour, including maternal aggression and lactating behaviour. Strikingly, mutant females display unique characteristics of male sexual and courtship behaviours such as mounting, pelvic thrust, solicitation, anogenital olfactory investigation, and emission of complex ultrasonic vocalizations towards male and female conspecific mice. The same behavioural phenotype is observed after VNO surgical removal in adult animals, and is not accompanied by disruption of the oestrous cycle and sex hormone levels. These findings suggest that VNO-mediated pheromone inputs act in wild-type females to repress male behaviour and activate female behaviours. Moreover, they imply that functional neuronal circuits underlying male-specific behaviours exist in the normal female mouse brain.     

Vasopressin alters female sexual behaviour by acting on the brain independently of alterations in blood pressure

Subcutaneous (s.c.) administration of Arg-vasopressin (AVP) prolongs retention of a learned behaviour and elevates arterial blood pressure. Intracerebroventricular (i.c.v.) injection of a thousandfold lower dose of AVP than needed with s.c. injection produces the same behavioural effect, suggesting that AVP acts on the brain to control behaviour. However, as i.c.v. injection of AVP also elevates arterial blood pressure, it was suggested that AVP, and perhaps other peptides as well, influences behaviour indirectly by eliciting a peripheral response, for example blood pressure changes, rather than by acting directly on the brain. The suprachiasmatic nuclei (SCN) of the hypothalamus, a source of vasopressin production, inhibit sexual receptivity in oestradiol-17 beta-treated ovariectomized rats during the light phase of the daily lighting cycle, leading to speculation that vasopressin might inhibit sexual behaviour. Here we report that i.c.v. injections of AVP (1, 4 or 10 ng) inhibit sexual behaviour in receptive rats. This behavioural response is prevented by i.c.v. injection of an antiserum to AVP 30 min before AVP injection. Subcutaneous injection of a high dose of AVP (1 microgram) has no behavioural effect but elevates arterial blood pressure within 30 min of administration. Intracerebroventricular injection of a behaviourally effective dose of AVP (1 ng) has no effect on blood pressure. The results provide direct evidence that AVP can alter behaviour by an action on the brain and independently of its effect on blood pressure.     

Ultrasonic frogs show hyperacute phonotaxis to female courtship calls

Sound communication plays a vital role in frog reproduction, in which vocal advertisement is generally the domain of males. Females are typically silent, but in a few anuran species they can produce a feeble reciprocal call or rapping sounds during courtship. Males of concave-eared torrent frogs (Odorrana tormota) have demonstrated ultrasonic communication capacity. Although females of O. tormota have an unusually well-developed vocal production system, it is unclear whether or not they produce calls or are only passive partners in a communication system dominated by males. Here we show that before ovulation, gravid females of O. tormota emit calls that are distinct from males' advertisement calls, having higher fundamental frequencies and harmonics and shorter call duration. In the field and in a quiet, darkened indoor arena, these female calls evoke vocalizations and extraordinarily precise positive phonotaxis (a localization error of <1 degrees ), rivalling that of vertebrates with the highest localization acuity (barn owls, dolphins, elephants and humans). The localization accuracy of O. tormota is remarkable in light of their small head size (interaural distance of <1 cm), and suggests an additional selective advantage of high-frequency hearing beyond the ability to avoid masking by low-frequency background noise.     

子宫切除术后妇女性生活分析与健康教育

目的了解妇女子宫切除术后性生活情况.方法选取我院2003年1月～2004年12月诊治285例子宫切除术后的妇女,采用调查问卷方式逐一面对面调查,比较术后性生活的情况,结果285例患者有115例(40.7%)术后有性生活,其中60.7%(70/116)表现为性欲下降.手术方式、手术范围在性生活恢复时间、性生活频度、性生活满意度等方面无显著差异(p＞0.05).患者对性方面的问题的处理,有53人(185%)咨询过医护人员,250例(87.7%)患者希望医护人员在性问题上给予帮助,并希望开设此类门诊.结论心理的压抑与恐惧常常是导致术后性功能障碍的重要方面,因此重视子宫切除术后妇女的心理状态,对患者实施性健康教育,将对改善这些妇女术后性功能异常有重要帮助.     

子宫切除术后妇女性生活分析与健康教育

目的了解妇女子宫切除术后性生活情况.方法选取我院2003年1月～2004年12月诊治285例子宫切除术后的妇女,采用调查问卷方式逐一面对面调查,比较术后性生活的情况,结果285例患者有115例(40.7%)术后有性生活,其中60.7%(70/116)表现为性欲下降.手术方式、手术范围在性生活恢复时间、性生活频度、性生活满意度等方面无显著差异(p＞0.05).患者对性方面的问题的处理,有53人(185%)咨询过医护人员,250例(87.7%)患者希望医护人员在性问题上给予帮助,并希望开设此类门诊.结论心理的压抑与恐惧常常是导致术后性功能障碍的重要方面,因此重视子宫切除术后妇女的心理状态,对患者实施性健康教育,将对改善这些妇女术后性功能异常有重要帮助.     

Corticotropin-releasing factor is a potent inhibitor of sexual receptivity in the female rat

Corticotropin-releasing factor (CRF), the recently characterized and synthesized 41-amino acid polypeptide isolated from ovine hypothalami, has been shown to be a potent stimulator of adenohypophyseal beta-endorphin and corticotropin (ACTH) secretion both in vitro and in vivo. In common with other regulatory peptides, CRF has also been demonstrated to possess extra-hypophysiotropic roles. Indeed, intracerebroventricularly (i.c.v.) administered CRF elicits several endocrine and behavioural responses compatible with the concept that this peptide could be a key signal in coordinating the organism's endocrine and behavioural responses to stressful and other adaptive stimuli. We now provide the first evidence for neurally placed CRF in the control of a specific hormone-dependent behavioural response and unequivocally demonstrate an extremely potent suppressive effect of CRF on sexual behaviour in the female rat when microinfused into the arcuate-ventromedial area of the hypothalamus (ARC-VMH) and the mesencephalic central grey (MCG).     

中国林蛙幼蛙性别诱导后性腺的组织学观察

对中国林蛙幼蛙性别诱导后的性腺进行了组织学观察,结果发现,诱导后雌性幼蛙性腺的组织学特征与自然分化的雌蛙幼蛙性腺组织结构没有明显差异.这些结果为中国林蛙养殖和性别诱导提供了必要的组织学证据.     

海洛因对母鼠体重、行为及肺中相关活性物质表达的影响

为探讨海洛因对母鼠体重、行为及肺中Bax蛋白、c-Fos蛋白和KGF表达的影响,对48例受孕小鼠(第8天开始)每天早晚分别注射0.2mL浓度为1.0、1.5和2.0g.L-1的海洛因溶液和等量生理盐水直到小鼠分娩,观察测量其体重和行为变化,采用免疫组织化学染色和体视学半定量方法检测胚胎15d、分娩1d、7d、15d的母鼠肺中Bax蛋白、c-Fos蛋白和KGF的表达情况.结果表明:注射海洛因后母鼠出现竖尾兴奋跑圈、四肢离地蹿起、腹泻等依赖症状;分娩后母鼠出现明显的烦躁不安、高度激怒、肌颤、扭体、饮食次数减少等症状,海洛因对母鼠行为的影响在一定范围内存在剂量效应和长时程效应.实验组各期母鼠的体重明显低于对照组,母鼠肺中Bax蛋白、c-Fos蛋白和KGF的表达强度与对照组相比显著增强(P0.01或P0.05),且随海洛因浓度的增大表达增强,但随着发育的进行,海洛因组母鼠肺中Bax蛋白、c-Fos蛋白和KGF的阳性表达逐渐减弱.海洛因影响母鼠的体重和行为及肺中Bax蛋白、c-Fos蛋白及KGF的表达.     

Effects of isolation after sexual experience on anxiety-like,depressive-like behaviors and affective states in male rats

Studies on social isolation have provided evidence for an enhanced anxiety-like phenotype, depressive-like symptoms and higher levels of 22-kHz ultrasonic vocalizations (USVs); whereas sexual experience could induce significant changes in affective states, decrease anxiety- and depressive-like responses. However, the behavioral and emotional alterations in male rats exposed to isolation after sexual experience remain poorly understood. Therefore, the present study examined anxiety- and depressive-like parameters, as well as USV emissions in male rats isolated for 1, 2, or 7 d following 1-week sexual (male-female paired housing) or social (male-male paired housing) interaction. Isolation for 1 d resulted in increased depressive-like symptoms, and 2-d isolation induced elevated anxiety-like behavior in sexually inexperienced rats, while rats with sexual experience exhibited comparable levels of emotionality at each isolation time. Moreover, isolated rats without sexual experience emitted less 22- and 50-kHz USVs, but sexually experienced rats exhibited similar affective states compared with control ones. These results suggested that prior sexual experience could have a modulatory effect on experimental rat emotional responses to isolation.     

超声显微镜的应用

用超声显微镜可测视金属和非金属材料的表面及表面层下附近的组织与缺陷，根据测视结果判定材料的弹性值，断裂韧性值等，它具有很重要的开发应用价值。