Odor information arrives first in the main olfactory bulb and is then broadcasted to the olfactory cortices and striatum. Downstream regions have unique cellular and connectivity architectures that may generate different coding patterns to the same odors. To reveal region-specific response features, tuning and decoding of single-unit populations, we recorded responses to the same odors under the same conditions across regions, namely, the main olfactory bulb (MOB), the anterior olfactory nucleus (AON), the anterior piriform cortex (aPC), and the olfactory tubercle of the ventral striatum (OT), of awake male mice. We focused on chemically closely related aldehydes that still create distinct percepts. The MOB had the highest decoding accuracy for aldehydes and was the only region encoding chemical similarity. The MOB had the highest fraction of inhibited responses and narrowly tuned odor-excited responses in terms of timing and odor selectivity. Downstream, the interconnected AON and aPC differed in their response patterns to the same stimuli. While odor-excited responses dominated the AON, the aPC had a comparably high fraction of odor-inhibited responses. Both cortices share a main output target that is the MOB. This prompted us to test if the two regions convey also different net outputs. Aldehydes activated AON terminals in the MOB as a bulk signal but inhibited those from the aPC. The differential cortical projection responses generalized to complex odors. In summary, olfactory regions reveal specialized features in their encoding with AON and aPC differing in their local computations, thereby generating inverse net centrifugal and intercortical outputs.

气味信息首先到达主嗅球，然后广播到嗅皮层和纹状体。下游区域具有独特的蜂窝和连接架构，可能会对相同的气味产生不同的编码模式。为了揭示区域特异性反应特征、单单位种群的调整和解码，我们记录了在相同条件下跨区域对相同气味的反应，即主嗅球 （MOB）、前嗅核 （AON）、前梨状皮层 （aPC） 和腹侧纹状体 （OT） 的嗅结节，清醒的雄性小鼠。我们专注于化学上密切相关的醛类，这些醛类仍然会产生不同的感知。MOB 对醛类的解码精度最高，并且是唯一编码化学相似性的区域。MOB 在时间和气味选择性方面具有最高比例的抑制反应和狭隘调谐的气味激发反应。在下游，互连的 AON 和 aPC 对相同刺激的反应模式不同。虽然气味激发反应在 AON 中占主导地位，但 aPC 的气味抑制反应的比例相对较高。两个 cortice 共享一个主输出目标，即 MOB。这促使我们测试这两个地区是否也传达不同的净输出。醛激活了 MOB 中的 AON 末端作为体信号，但抑制了来自 aPC 的 AON 末端。差异皮层投射反应普遍性为复杂的气味。总之，嗅觉区域在编码中揭示了特殊特征，AON 和 aPC 的局部计算不同，从而产生逆净离心和皮层间输出。