The olfactory bulb (OB) is the first relay station in the olfactory system and functions as a crucial hub. It can represent odor information precisely and accurately in an ever-changing environment. As the only output neurons in the OB, mitral/tufted cells encode information such as odor identity and concentration. Recently, the neural strategies and mechanisms underlying odor representation and encoding in the OB have been investigated extensively. Here we review the main progress on this topic. We first review the neurons and circuits involved in odor representation, including the different cell types in the OB and the neural circuits within and beyond the OB. We will then discuss how two different coding strategies-spatial coding and temporal coding-work in the rodent OB. Finally, we discuss potential future directions for this research topic. Overall, this review provides a comprehensive description of our current understanding of how odor information is represented and encoded by mitral/tufted cells in the OB.
嗅球是嗅觉系统中的第一个中继站，起着关键的枢纽作用，能在不断变化的环境中精确地表征气味信息。作为嗅球中唯一的输出神经元，僧帽细胞/簇状细胞编码诸如气味类型和浓度等信息。近年来，针对嗅球中气味表征和编码的潜在神经策略和机制已开展了广泛的研究。本文对该领域的主要进展进行了综述，首先回顾了涉及气味表征的神经元和相关环路，包括嗅球中的不同细胞类型以及嗅球内部和外部的神经回路；随后讨论了两种不同的编码策略（空间编码和时间编码）在啮齿动物嗅球中的工作原理；最后，对该研究领域的潜在未来方向展开讨论。综上，本文就目前僧帽细胞/簇状细胞在嗅球中如何表征和编码气味信息进行了全面总结。.
嗅球是嗅觉系统中的第一个中继站，起着关键的枢纽作用，能在不断变化的环境中精确地表征气味信息。作为嗅球中唯一的输出神经元，僧帽细胞/簇状细胞编码诸如气味类型和浓度等信息。近年来，针对嗅球中气味表征和编码的潜在神经策略和机制已开展了广泛的研究。本文对该领域的主要进展进行了综述，首先回顾了涉及气味表征的神经元和相关环路，包括嗅球中的不同细胞类型以及嗅球内部和外部的神经回路；随后讨论了两种不同的编码策略（空间编码和时间编码）在啮齿动物嗅球中的工作原理；最后，对该研究领域的潜在未来方向展开讨论。综上，本文就目前僧帽细胞/簇状细胞在嗅球中如何表征和编码气味信息进行了全面总结。
Keywords: Information encoding; Mitral/tufted cells; Neural representation; Odor identity; Olfactory bulb.