Centre de Recherche en Neurosciences de Lyon (CRNL) Equipe Olfaction: du codage à la mémoire, CNRS UMR 5292-INSERM U1028-Université Lyon 1, Lyon, France.
PLoS One. 2012;7(7):e40927. doi: 10.1371/journal.pone.0040927. Epub 2012 Jul 17.
A key feature of mammalian olfactory perception is that sensory input is intimately related to respiration. Different authors have considered respiratory dynamics not only as a simple vector for odor molecules but also as an integral part of olfactory perception. Thus, rats adapt their sniffing strategy, both in frequency and flow rate, when performing odor-related tasks. The question of how frequency and flow rate jointly impact the spatio-temporal representation of odor in the olfactory bulb (OB) has not yet been answered. In the present paper, we addressed this question using a simulated nasal airflow protocol on anesthetized rats combined with voltage-sensitive dye imaging (VSDi) of odor-evoked OB glomerular maps. Glomerular responses displayed a tonic component during odor stimulation with a superimposed phasic component phase-locked to the sampling pattern. We showed that a high sniffing frequency (10 Hz) retained the ability to shape OB activity and that the tonic and phasic components of the VSDi responses were dependent on flow rate and inspiration volume, respectively. Both sniffing parameters jointly affected OB responses to odor such that the reduced activity level induced by a frequency increase was compensated by an increased flow rate.
哺乳动物嗅觉感知的一个关键特征是感觉输入与呼吸密切相关。不同的作者不仅将呼吸动力学视为气味分子的简单载体，而且将其视为嗅觉感知的一个组成部分。因此，大鼠在执行与气味相关的任务时会调整其嗅探策略，包括频率和流速。频率和流速如何共同影响嗅球（OB）中气味的时空表示，这个问题尚未得到解答。在本文中，我们使用麻醉大鼠的模拟鼻气流方案和嗅球肾小球图的电压敏感染料成像（VSDi）来解决这个问题。肾小球反应在气味刺激期间显示出紧张成分，叠加了与采样模式锁相的相位性成分。我们表明，高嗅探频率（10 Hz）能够保持对 OB 活动的塑造能力，VSDi 反应的紧张和相位成分分别取决于流速和吸气量。这两个嗅探参数共同影响 OB 对气味的反应，使得增加频率引起的活动水平降低被增加的流速所补偿。
