The representation of odors in the locust antennal lobe with its >2,000 glomeruli has long remained a perplexing puzzle. We employed the CRISPR-Cas9 system to generate transgenic locusts expressing the genetically encoded calcium indicator GCaMP in olfactory sensory neurons. Using two-photon functional imaging, we mapped the spatial activation patterns representing a wide range of ecologically relevant odors across all six developmental stages. Our findings reveal a functionally ring-shaped organization of the antennal lobe composed of specific glomerular clusters. This configuration establishes an odor-specific chemotopic representation by encoding different chemical classes and ecologically distinct odors in the form of glomerular rings. The ring-shaped glomerular arrangement, which we confirm by selective targeting of OR70a-expressing sensory neurons, occurs throughout development, and the odor-coding pattern within the glomerular population is consistent across developmental stages. Mechanistically, this unconventional spatial olfactory code reflects the locust-specific and multiplexed glomerular innervation pattern of the antennal lobe.

蝗虫触角叶及其超过 2,000 个肾小球的气味表征长期以来一直是一个令人困惑的谜题。我们利用 CRISPR-Cas9 系统生成转基因蝗虫，在嗅觉感觉神经元中表达基因编码的钙指示剂 GCaMP。使用双光子功能成像，我们绘制了代表所有六个发育阶段的各种生态相关气味的空间激活模式。我们的研究结果揭示了由特定肾小球簇组成的触角叶的功能性环形组织。这种配置通过以肾小球环的形式编码不同的化学类别和生态上不同的气味，建立了气味特异性的化学位表示。我们通过选择性靶向表达 OR70a 的感觉神经元来证实环形肾小球排列发生在整个发育过程中，并且肾小球群体内的气味编码模式在整个发育阶段是一致的。从机制上讲，这种非常规的空间嗅觉代码反映了蝗虫触角叶的特异性和多重肾小球神经支配模式。