哺乳動物中雄性與雌性行為之間的巨大差別是怎樣形成的？ 關(guān)于這個問題的主導(dǎo)理論是,，性腺激素在腦發(fā)育早期誘導(dǎo)神經(jīng)回路,，讓它們?nèi)フT導(dǎo)或抑制雄性或雌性特征。但新的研究工作表明,，雄性或雌性的交配偏好并不是在發(fā)育過程中確定的,。信息素感知已被發(fā)現(xiàn)能夠改變成年雌性實(shí)驗(yàn)鼠的性行為。這一現(xiàn)象的關(guān)鍵是“犁鼻器”（vomeronasal organ）,，一種功能未知的輔助嗅覺器官,，存在于鼻與嘴之間的犁骨（vomer bone）中。“犁鼻器”有缺陷的雌性會表現(xiàn)出雄性性行為,，說明雄性和雌性行為的促動回路都存在于每個性別的腦中,，是通過性別特異性的傳感調(diào)控機(jī)制打開或關(guān)閉的,。人類是在胎兒發(fā)育過程中失去“犁鼻器”的，但這一發(fā)現(xiàn)為研究人類的性別特異性行為開辟了新途徑,。
原始出處：
Nature 448, 1009-1014 (30 August 2007) | doi:10.1038/nature06089; Received 15 May 2007; Accepted 17 July 2007; Published online 5 August 2007
A functional circuit underlying male sexual behaviour in the female mouse brain
Tali Kimchi1, Jennings Xu1 & Catherine Dulac1
Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, Harvard University, Cambridge, Massachusetts 02138, USA
Correspondence to: Tali Kimchi1Catherine Dulac1 Correspondence and requests for materials should be addressed to C.D. (Email: [email protected]) or T.K. (Email: [email protected]).
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.
