Department of Molecular and Cellular Biology, Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA.
Proc Natl Acad Sci U S A. 2010 Mar 16;107(11):5172-7. doi: 10.1073/pnas.0915147107. Epub 2010 Mar 1.
The rodent vomeronasal system plays a critical role in mediating pheromone-evoked social and sexual behaviors. Recent studies of the anatomical and molecular architecture of the vomeronasal organ (VNO) and of its synaptic target, the accessory olfactory bulb (AOB), have suggested that unique features underlie vomeronasal sensory processing. However, the neuronal representation of pheromonal information leading to specific behavioral and endocrine responses has remained largely unexplored due to the experimental difficulty of precise stimulus delivery to the VNO. To determine the basic rules of information processing in the vomeronasal system, we developed a unique preparation that allows controlled and repeated stimulus delivery to the VNO and combined this approach with multisite recordings of neuronal activity in the AOB. We found that urine, a well-characterized pheromone source in mammals, as well as saliva, activates AOB neurons in a manner that reliably encodes the donor animal's sexual and genetic status. We also identified a significant fraction of AOB neurons that respond robustly and selectively to predator cues, suggesting an expanded role for the vomeronasal system in both conspecific and interspecific recognition. Further analysis reveals that mixed stimuli from distinct sources evoke synergistic responses in AOB neurons, thereby supporting the notion of integrative processing of chemosensory information.
啮齿动物的犁鼻器系统在介导信息素引发的社交和性行为方面起着关键作用。最近对犁鼻器（VNO）及其突触靶标副嗅球（AOB）的解剖结构和分子结构的研究表明，犁鼻器感觉处理的基础是独特的特征。然而，由于向 VNO 精确传递刺激的实验难度，导致信息导致特定行为和内分泌反应的信息仍在很大程度上未被探索。为了确定犁鼻器系统中的信息处理基本规则，我们开发了一种独特的制剂，允许对 VNO 进行受控和重复的刺激传递，并将这种方法与 AOB 中的神经元活动的多部位记录相结合。我们发现，尿液（哺乳动物中一种特征明确的信息素来源）以及唾液以可靠地编码供体动物的性和遗传状态的方式激活 AOB 神经元。我们还发现了相当一部分 AOB 神经元对捕食者线索有强烈而选择性的反应，这表明犁鼻器系统在同种和种间识别中具有扩展的作用。进一步的分析表明，来自不同来源的混合刺激在 AOB 神经元中引发协同反应，从而支持对化学感觉信息进行综合处理的概念。
