2010年12月8日，我所罗敏敏实验室在The Journal of Neuroscience 杂志发表题为“Diverse Patterns of Odor Representation by Neurons in the Anterior Piriform Cortex of Awake Mice”的文章。 该文首次描述了清醒小鼠的嗅皮层神经元对气味信息是如何反应和编码的。
哺乳动物的嗅皮层直接接受来之嗅球的信息，并被认为是形成气味感知的重要部位，但现在还不清楚嗅皮层神经元是如何编码和表征气味信息的。本文通过对清醒动物的嗅皮层神经元进行细胞外记录，研究了嗅皮层中单个神经元对气味是如何反应的。记录完成后标记出神经元，并通过所标记细胞的形态，以及神经递质特性把记录的细胞分为主神经元以及不同类型的中间神经元。本文作者发现嗅皮层神经元对气味信息有着非常不同的选择性和反应调谐特性。在嗅皮层上，大约有1/4的主神经元可以被分子结构不同的气味广泛激活，有1/4的主神经元被分子结构不同的气味广泛抑制，而其他约1/2的主神经元对实验中用到的大部分气味没有任何反应，有非常高的气味选择性。我们还发现GABA神经元对实验中用到的气味选择性较低，且很少会被气味抑制。其他非GABA的中间神经元则被许多气味强烈抑制。总的来说，这些数据显示在清醒小鼠的嗅皮层上气味信息是被众多选择性不同的神经元表征和编码的，这些反应调谐曲线不同的神经元也许在气味感知和编码中发挥着不同的作用。
本文的第一作者为占成，通讯作者为罗敏敏。此项研究由科技部863及973计划及北京市科委资助，在北京生命科学研究所完成。（生物谷Bioon.com）
生物谷推荐原文出处：
The Journal of Neuroscience doi:10.1523/JNEUROSCI.4400-10.2010
Diverse Patterns of Odor Representation by Neurons in the Anterior Piriform Cortex of Awake Mice
Cheng Zhan1,2 and Minmin Luo2,3
1Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics–Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China, 2National Institute of Biological Sciences, Beijing 102206, China, and 3School of Life Sciences, Tsinghua University, Beijing 100084, China
Correspondence should be addressed to Minmin Luo, National Institute of Biological Sciences, 7 Science Park Road, Zhongguancun Life Science Park, Beijing 102206, China. Email: luominmin@nibs.ac.cn
The mammalian piriform cortex receives direct synaptic input from the olfactory bulb and is likely the locus for the formation of odor percept. It remains unclear how individual cortical neurons encode olfactory information in unanesthetized animals. By single-cell recordings from head-restrained awake mice, we studied the odor response profiles of individual neurons in the anterior piriform cortex (aPCX). Neurons were juxtacellularly labeled, and their cell types were determined by their morphology and neurotransmitter phenotypes. We found a considerable level of variability in selectivity patterns among pyramidal neurons (PNs). Approximately one-quarter of PNs were broadly activated by structurally dissimilar odorants, whereas the excitations to the rest of PNs were highly selective. Broad inhibition was only observed from a subpopulation of PNs. GABAergic neurons displayed nonselective excitatory responses to test odorants and rarely exhibited inhibition. In contrast, non-GABAergic nonpyramidal neurons in the deep layer tended to be strongly inhibited by multiple different odorants. Our findings suggest that odor representation is accomplished by both broadly tuned and narrow-tuned PNs in the aPCX of awake animals. In addition, various types of interneurons may play different roles in the intracortical processing of olfactory information.
