Department Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
J Neurosci. 2012 Feb 1;32(5):1653-9. doi: 10.1523/JNEUROSCI.4395-11.2012.
Sniffing, a high-frequency, highly rhythmic inhalation and exhalation of air through the nose, plays an important role in rodent olfaction. Similarly, whisking, the active rhythmic movement of whiskers, plays an important role in rodent tactile sensation. Rodents whisk and sniff during exploratory behavior to sample odorants and surfaces. Whisking is thought to be coordinated with sniffing and normal respiratory behavior, but the precise temporal relationships between these movements are not known. Here, using direct measurements of whisking and respiratory movements, we examined the strength and temporal dynamics of the correlation between large-amplitude whisker movements and respiratory rhythm in mice. Whisking movements were detected using an optical sensor, and respiration was monitored with a thermistor placed close to the nostril. Our measurements revealed that breathing and whisking movements were significantly correlated only when the whisking rhythm was <5 Hz. Only a fraction (~13%) of all large-amplitude whisker movements occurred during episodes of high-frequency (>5 Hz) respiration typically associated with sniffing. Our results show that that the rhythms of respiratory and whisking movements are correlated only during low-frequency whisking and respiration. High-frequency whisking and sniffing behaviors are not correlated. We conclude that whisking and respiratory rhythms are generated by independent pattern-generating mechanisms.
嗅探，即通过鼻子高频、高节奏地吸入和呼出空气，在啮齿动物嗅觉中起着重要作用。同样，胡须的主动有节奏运动——刷动，在啮齿动物触觉中也起着重要作用。啮齿动物在探索行为中会刷动和嗅探，以采样气味和表面。人们认为刷动与嗅探和正常呼吸行为协调一致，但这些运动之间的确切时间关系尚不清楚。在这里，我们使用对胡须和呼吸运动的直接测量，研究了在小鼠中大振幅胡须运动与呼吸节律之间的相关性的强度和时间动态。我们使用光学传感器检测胡须运动，并用靠近鼻孔的热敏电阻监测呼吸。我们的测量结果表明，只有当刷动节律<5 Hz 时，呼吸和刷动运动才具有显著相关性。只有一小部分（约 13%）的大振幅胡须运动发生在与嗅探相关的高频（>5 Hz）呼吸期。我们的结果表明，呼吸和胡须运动的节律仅在低频胡须和呼吸时相关。高频刷动和嗅探行为不相关。我们得出结论，胡须和呼吸节律是由独立的模式生成机制产生的。
