Department of Physiology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan.
Annu Rev Neurosci. 2011;34:467-99. doi: 10.1146/annurev-neuro-112210-112917.
Odor signals received by odorant receptors (ORs) expressed by olfactory sensory neurons (OSNs) in the olfactory epithelium (OE) are represented as an odor map in the olfactory bulb (OB). In the mouse, there are ~1,000 different OR species, and each OSN expresses only one functional OR gene in a monoallelic manner. Furthermore, OSN axons expressing the same type of OR converge on a specific target site in the OB, forming a glomerular structure. Because each glomerulus represents a single OR species, and a single odorant can interact with multiple OR species, odor signals received in the OE are converted into a topographic map of multiple glomeruli activated with varying magnitudes. Here we review recent progress in the study of the mammalian olfactory system, focusing on the formation of the olfactory map and the transmission of topographical information in the OB to the olfactory cortex to elicit various behaviors.
气味信号由嗅上皮（OE）中的嗅觉感觉神经元（OSN）表达的气味受体（OR）接收，这些信号在嗅球（OB）中表现为气味图谱。在小鼠中，有约 1000 种不同的 OR 物种，每个 OSN 以单等位基因的方式仅表达一种功能性 OR 基因。此外，表达相同类型 OR 的 OSN 轴突在 OB 中汇聚到特定的靶位，形成一个肾小球结构。由于每个肾小球代表一种单一的 OR 物种，并且一种气味可以与多种 OR 物种相互作用，因此 OE 中接收到的气味信号被转换为多个以不同强度激活的肾小球的拓扑图谱。在这里，我们综述了哺乳动物嗅觉系统研究的最新进展，重点介绍了嗅觉图谱的形成以及 OB 中拓扑信息向嗅觉皮层的传递，以引发各种行为。
