Yan Zhiqiang, Tan Jie, Qin Chang, Lu Yao, Ding Cheng, Luo Minmin
Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
Neuron. 2008 May 22;58(4):613-24. doi: 10.1016/j.neuron.2008.03.012.
Olfactory sensory neurons expressing a common receptor gene converge onto one or a few glomeruli with stereotyped positions within the mouse main olfactory bulb (MOB), producing a map of approximately 1800 olfactory columns representing approximately 1000 odorant receptors. Here, we report that this precise olfactory map is maintained over several synapses that ultimately cross MOB hemispheres to link bilateral isofunctional olfactory columns. Focal injection of tracer into genetically identified glomeruli revealed an exquisite topography that involves a bilateral connection via the anterior olfactory nucleus pars externa (AONpE) that links isofunctional olfactory columns in the contralateral MOB. Physiological and behavioral assays revealed an important role for the AONpE in bilateral exchange of odorant-specific information. These results indicate that the interbulbar link through the AONpE integrates bilateral olfactory sensory maps and exchanges olfactory information, positioning it as a unique model system for studying interhemispheric connections.
表达共同受体基因的嗅觉感觉神经元会汇聚到小鼠主嗅球（MOB）内具有固定位置的一个或几个肾小球上，形成一张由大约1800个嗅觉柱组成的图谱，代表大约1000种气味受体。在此，我们报告，这种精确的嗅觉图谱在多个突触中得以维持，这些突触最终穿过MOB半球，连接双侧同功能的嗅觉柱。将示踪剂局部注射到基因鉴定的肾小球中，揭示了一种精细的拓扑结构，该结构涉及通过外侧前嗅核（AONpE）的双侧连接，这种连接将对侧MOB中的同功能嗅觉柱联系起来。生理和行为分析揭示了AONpE在气味特异性信息的双侧交换中的重要作用。这些结果表明，通过AONpE的球间连接整合了双侧嗅觉感觉图谱并交换嗅觉信息，使其成为研究半球间连接的独特模型系统。
