Weiler Elke, Deutsch Swetlana, Apfelbach Raimund
Department of Neurophysiology, Faculty of Medicine, Institute of Physiology, Ruhr-University Bochum, D-44780 Bochum, Germany.
Chem Senses. 2006 Sep;31(7):641-7. doi: 10.1093/chemse/bjl004. Epub 2006 Jun 27.
Salt, known as taste quality, is generally neglected in olfaction, although the olfactory sensory neurons stretch into the salty nasal mucus covering the olfactory epithelium (OE). Using a psychophysical approach, we directly and functionally demonstrate in the awake rat for a variety of structurally diverse odorants that sodium is a critical factor for olfactory perception and sensitivity, both very important components of mammalian communication and sexual behavior. Bathing the olfactory mucus with an iso-osmotic sodium-free buffer solution results in severe deficits in odorant detection. However, sensitivity returns fully within a few hours, indicating continuous mucus production. In the presence of sodium in the mucus covering the OE, all odorants induce odorant-specific c-Fos expression in the olfactory bulb. Yet, if sodium is absent in the mucus, no c-Fos expression is induced as demonstrated for n-octanal. Our noninvasive approach to induce anosmia in mammals here presented--which is fully reversible within hours--opens new possibilities to study the functions of olfactory communication in awake animals.
盐，作为一种味觉特质，在嗅觉中通常被忽视，尽管嗅觉感觉神经元延伸到覆盖嗅上皮（OE）的含盐鼻黏液中。我们采用心理物理学方法，在清醒的大鼠中直接且功能性地证明，对于多种结构各异的气味剂而言，钠是嗅觉感知和灵敏度的关键因素，而嗅觉感知和灵敏度是哺乳动物交流及性行为的两个非常重要的组成部分。用等渗无钠缓冲溶液冲洗嗅黏液会导致气味剂检测出现严重缺陷。然而，灵敏度会在数小时内完全恢复，这表明黏液在持续产生。在覆盖OE的黏液中存在钠的情况下，所有气味剂都会在嗅球中诱导出气味剂特异性的c-Fos表达。然而，如果黏液中不存在钠，就不会诱导出c-Fos表达，正辛醛的情况就是如此。我们在此提出的在哺乳动物中诱导嗅觉缺失的非侵入性方法——数小时内完全可逆——为研究清醒动物中嗅觉交流的功能开辟了新的可能性。
