Kikuta Shu, Han Bing, Yamasoba Tatsuya
Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, Nihon University, 30-1, Oyaguchi Kami-cho, Itabashi-ku, Tokyo 173-8610, Japan.
Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
J Clin Med. 2023 Jul 29;12(15):5007. doi: 10.3390/jcm12155007.
Post-viral olfactory dysfunction (PVOD) is a neurogenic disorder caused by a common cold virus. Based on the homology of deduced amino acid sequences, olfactory sensory neurons (OSNs) in both mice and humans express either class I or class II odorant receptor genes encoding class I and class II OSNs. The purpose of this study was to determine whether OSN damage in PVOD occurs uniformly in both neuron types.
The characteristics of PVOD patients were compared with those of patients with chronic rhinosinusitis (CRS) or post-traumatic olfactory dysfunction (PTOD). Briefly, subjects underwent orthonasal olfaction tests using five different odors (T&T odors) and a retronasal olfaction test using a single odor (IVO odor). The regions in the mouse olfactory bulb (OB) activated by the T&T and the IVO odors were also examined.
Multivariate analysis of 307 cases of olfactory dysfunction (PVOD, 118 cases; CRS, 161 cases; and PTOD, 28 cases) revealed that a combination of responses to the IVO odor, but not to the T&T odors, is characteristic of PVOD, with high specificity ( < 0.001). Imaging analysis of GCaMP3 mice showed that the IVO odor selectively activated the OB region in which the axons of class I OSNs converged, whereas the T&T odors broadly activated the OB region in which axons of class I and class II OSNs converged.
A response to T&T odors, but not IVO odor, in PVOD suggests that class I OSNs are injured preferentially, and that OSN damage in PVOD may occur heterogeneously in a neuron-type-dependent manner.
病毒感染后嗅觉功能障碍（PVOD）是一种由普通感冒病毒引起的神经源性疾病。基于推导的氨基酸序列同源性，小鼠和人类的嗅觉感觉神经元（OSN）均表达编码I类和II类OSN的I类或II类气味受体基因。本研究的目的是确定PVOD中OSN损伤在两种神经元类型中是否均一发生。
将PVOD患者的特征与慢性鼻窦炎（CRS）或创伤后嗅觉功能障碍（PTOD）患者的特征进行比较。简要地说，受试者使用五种不同气味（T&T气味）进行经鼻嗅觉测试，并使用单一气味（IVO气味）进行鼻后嗅觉测试。还检查了T&T和IVO气味激活的小鼠嗅球（OB）区域。
对307例嗅觉功能障碍患者（PVOD 118例、CRS 161例、PTOD 28例）进行多变量分析发现，对IVO气味而非T&T气味的反应组合是PVOD的特征，特异性高（<0.001）。对GCaMP3小鼠的成像分析表明，IVO气味选择性激活I类OSN轴突汇聚的OB区域，而T&T气味广泛激活I类和II类OSN轴突汇聚的OB区域。
PVOD中对T&T气味而非IVO气味的反应表明I类OSN优先受损，且PVOD中的OSN损伤可能以神经元类型依赖的方式异质性发生。
