Kondo Kenji, Kikuta Shu, Ueha Rumi, Suzukawa Keigo, Yamasoba Tatsuya
Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
Front Aging Neurosci. 2020 Jul 7;12:208. doi: 10.3389/fnagi.2020.00208. eCollection 2020.
Like other sensory systems, olfactory function deteriorates with age. Epidemiological studies have revealed that the incidence of olfactory dysfunction increases at the age of 60 and older and males are more affected than females. Moreover, smoking, heavy alcohol use, sinonasal diseases, and Down's syndrome are associated with an increased incidence of olfactory dysfunction. Although the pathophysiology of olfactory dysfunction in humans remains largely unknown, studies in laboratory animals have demonstrated that both the peripheral and central olfactory nervous systems are affected by aging. Aged olfactory neuroepithelium in the nasal cavity shows the loss of mature olfactory neurons, replacement of olfactory neuroepithelium by respiratory epithelium, and a decrease in basal cell proliferation both in the normal state and after injury. In the central olfactory pathway, a decrease in the turnover of interneurons in the olfactory bulb (OB) and reduced activity in the olfactory cortex under olfactory stimulation is observed. Recently, the association between olfactory impairment and neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), has gained attention. Evidence-based pharmacotherapy to suppress or improve age-related olfactory dysfunction has not yet been established, but preliminary results suggest that olfactory training using odorants may be useful to improve some aspects of age-related olfactory impairment.
与其他感觉系统一样，嗅觉功能会随着年龄增长而衰退。流行病学研究表明，嗅觉功能障碍的发病率在60岁及以上人群中会增加，且男性比女性受影响更严重。此外，吸烟、大量饮酒、鼻鼻窦疾病和唐氏综合征都与嗅觉功能障碍发病率的增加有关。虽然人类嗅觉功能障碍的病理生理学在很大程度上仍不为人所知，但对实验动物的研究表明，外周和中枢嗅觉神经系统都会受到衰老的影响。鼻腔中老化的嗅觉神经上皮显示出成熟嗅觉神经元的丧失、呼吸上皮对嗅觉神经上皮的替代，以及在正常状态和损伤后基底细胞增殖的减少。在中枢嗅觉通路中，观察到嗅球（OB）中间神经元的更新减少以及嗅觉刺激下嗅觉皮质的活性降低。最近，嗅觉障碍与神经退行性疾病，如阿尔茨海默病（AD）和帕金森病（PD）之间的关联受到了关注。抑制或改善与年龄相关的嗅觉功能障碍的循证药物治疗尚未确立，但初步结果表明，使用气味剂进行嗅觉训练可能有助于改善与年龄相关的嗅觉障碍的某些方面。
