Osmanski B F, Martin C, Montaldo G, Lanièce P, Pain F, Tanter M, Gurden H
Institut Langevin, ESPCI ParisTech, CNRS UMR7587, Inserm U979, Université Paris Diderot 7, 1 rue Jussieu, 75005 Paris, France.
Laboratoire d'Imagerie et Modélisation en Neurobiologie et Cancérologie, CNRS UMR8165, Université Paris Diderot 7 et Université Paris Sud, 91405 Orsay France.
Neuroimage. 2014 Jul 15;95:176-84. doi: 10.1016/j.neuroimage.2014.03.054. Epub 2014 Mar 24.
Topographic representation of the outside world is a key feature of sensory systems, but so far it has been difficult to define how the activity pattern of the olfactory information is distributed at successive stages in the olfactory system. We studied odor-evoked activation patterns in the main olfactory bulb and the anterior piriform cortex of rats using functional ultrasound (fUS) imaging. fUS imaging is based on the use of ultrafast ultrasound scanners and detects variations in the local blood volume during brain activation. It makes deep brain imaging of ventral structures, such as the piriform cortex, possible. Stimulation with two different odors (hexanal and pentylacetate) induced the activation of odor-specific zones that were spatially segregated in the main olfactory bulb. Interestingly, the same odorants triggered the activation of the entire anterior piriform cortex, in all layers, with no distinguishable odor-specific areas detected in the power Doppler images. These fUS imaging results confirm the spatial distribution of odor-evoked activity in the main olfactory bulb, and furthermore, they reveal the absence of such a distribution in the anterior piriform cortex at the macroscopic scale in vivo.
外界的地形表征是感觉系统的一个关键特征，但到目前为止，很难确定嗅觉信息的活动模式在嗅觉系统的连续阶段是如何分布的。我们使用功能超声（fUS）成像研究了大鼠主嗅球和前梨状皮质中气味诱发的激活模式。fUS成像基于超快超声扫描仪的使用，并在大脑激活期间检测局部血容量的变化。它使得对诸如梨状皮质等腹侧结构进行深部脑成像成为可能。用两种不同的气味（己醛和乙酸戊酯）进行刺激，诱导了在主嗅球中空间上分离的气味特异性区域的激活。有趣的是，相同的气味剂触发了整个前梨状皮质各层的激活，在功率多普勒图像中未检测到可区分的气味特异性区域。这些fUS成像结果证实了主嗅球中气味诱发活动的空间分布，此外，它们还揭示了在体内宏观尺度上前梨状皮质中不存在这种分布。
