Salazar Ignacio, Sanchez-Quinteiro Pablo, Barrios Arthur W, López Amado Manuel, Vega José A
Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Unit of Anatomy and Embryology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain.
Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Unit of Anatomy and Embryology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain.
Handb Clin Neurol. 2019;164:47-65. doi: 10.1016/B978-0-444-63855-7.00004-6.
The classic notion that humans are microsmatic animals was born from comparative anatomy studies showing the reduction in the size of both the olfactory bulbs and the limbic brain relative to the whole brain. However, the human olfactory system contains a number of neurons comparable to that of most other mammals, and humans have exquisite olfactory abilities. Major advances in molecular and genetic research have resulted in the identification of extremely large gene families that express receptors for sensing odors. Such advances have led to a renaissance of studies focused on both human and nonhuman aspects of olfactory physiology and function. Evidence that olfactory dysfunction is among the earliest signs of a number of neurodegenerative and neuropsychiatric disorders has led to considerable interest in the use of olfactory epithelial biopsies for potentially identifying such disorders. Moreover, the unique features of the olfactory ensheathing cells have made the olfactory mucosa a promising and unexpected source of cells for treating spinal cord injuries and other neural injuries in which cell guidance is critical. The olfactory system of humans and other primates differs in many ways from that of other species. In this chapter we provide an overview of the anatomy of not only the human olfactory mucosa but of mucosae from a range of mammals from which more detailed information is available. Basic information regarding the general organization of the olfactory mucosa, including its receptor cells and the large number of other cell types critical for their maintenance and function, is provided. Cross-species comparisons are made when appropriate. The polemic issue of the human vomeronasal organ in both the adult and fetus is discussed, along with recent findings regarding olfactory subsystems within the nose of a number of mammals (e.g., the septal organ and Grüneberg ganglion).
人类是嗅觉不灵敏动物这一经典观念源于比较解剖学研究，该研究表明嗅球和边缘脑相对于全脑的体积减小。然而，人类嗅觉系统包含的神经元数量与大多数其他哺乳动物相当，而且人类具有敏锐的嗅觉能力。分子和遗传学研究的重大进展已导致识别出极大的基因家族，这些基因家族表达用于感知气味的受体。这些进展促使了对嗅觉生理学和功能的人类及非人类方面研究的复兴。嗅觉功能障碍是多种神经退行性和神经精神疾病最早症状之一的证据，引发了人们对使用嗅上皮活检来潜在识别此类疾病的浓厚兴趣。此外，嗅鞘细胞的独特特性使嗅黏膜成为治疗脊髓损伤和其他细胞导向至关重要的神经损伤的有前景且出人意料的细胞来源。人类和其他灵长类动物的嗅觉系统在许多方面与其他物种不同。在本章中，我们不仅概述了人类嗅黏膜的解剖结构，并概述了一系列有更详细信息的哺乳动物的黏膜解剖结构。提供了有关嗅黏膜总体组织结构的基本信息，包括其受体细胞以及对其维持和功能至关重要的大量其他细胞类型。在适当的时候进行跨物种比较。讨论了成人和胎儿中人类犁鼻器这一有争议的问题，以及关于一些哺乳动物鼻腔内嗅觉子系统（如鼻中隔器官和格伦贝格神经节）的最新发现。
