GIGA Neurosciences, University of Liège, Belgium.
Brain Res. 2011 Jul 21;1402:20-9. doi: 10.1016/j.brainres.2011.05.035. Epub 2011 May 23.
Previous studies have shown that female preferences for male pheromones depend on the female's reproductive condition and the dominance status of the male. However, it is unknown which olfactory system detects the odors that result in a preference for a dominant male. Therefore, in the present study, we asked whether dominant versus subordinate male urinary odors differentially activate the main and accessory olfactory systems in female (C57Bl/6j) mice by monitoring the induction of the immediate early gene, c-fos. A more robust induction of Fos was observed in female mice which had direct nasal contact with dominant male urinary odors in four specific segments of the accessory olfactory system, i.e., the posteroventral part of the medial amygdala, the bed nucleus of the stria terminalis, the medial part of the preoptic nucleus and the ventrolateral part of the ventromedial hypothalamus, compared to females that were exposed to subordinate male urine. This greater activation of the accessory olfactory pathway by dominant male urine suggests that there are differences in the nonvolatile components of dominant versus subordinate male urine that are detected by the vomeronasal organ. By contrast, subordinate male urinary odors induced a greater activation in the piriform cortex which is part of the main olfactory system, suggesting that female mice discriminate between dominant and subordinate male urine using their main olfactory system as well.
先前的研究表明，女性对男性信息素的偏好取决于女性的生殖状况和男性的支配地位。然而，目前尚不清楚哪种嗅觉系统能够检测到导致对优势雄性偏好的气味。因此，在本研究中，我们通过监测即刻早期基因 c-fos 的诱导，询问优势雄性与从属雄性尿液气味是否会以不同的方式激活雌性（C57Bl/6j）小鼠的主要和辅助嗅觉系统。与接触从属雄性尿液的雌性相比，直接接触优势雄性尿液的雌性在辅助嗅觉系统的四个特定区域（即杏仁内侧后腹核、终纹床核、视前核的内侧部和腹内侧下丘脑的外侧部）中观察到 Fos 的诱导更强烈。与接触从属雄性尿液的雌性相比，优势雄性尿液对辅助嗅觉通路的更大激活表明，优势雄性尿液和从属雄性尿液的非挥发性成分存在差异，这些差异是由犁鼻器检测到的。相比之下，从属雄性尿液诱导了更多的梨状皮层的激活，而梨状皮层是主要嗅觉系统的一部分，这表明雌性小鼠也使用主要嗅觉系统来区分优势和从属雄性尿液。
