The main reason is the complicated anatomic structure of the nasal cavity and the special physiological location of the olfactoryregion, which has caused much trouble in direct experiment studies.
这主要是由于鼻腔的复杂结构及嗅区的特殊生理位置，为直接的嗅觉实验研究带来了不少困难。
2
In this review, we unraveled coding patterns of two olfactory systems for information recognition at three levels: olfactory receptor, olfactory bulb and higher brain region beyond the olfactory bulb.