2010年12月8日,，我所羅敏敏實(shí)驗(yàn)室在The Journal of Neuroscience 雜志發(fā)表題為“Diverse Patterns of Odor Representation by Neurons in the Anterior Piriform Cortex of Awake Mice”的文章,。 該文首次描述了清醒小鼠的嗅皮層神經(jīng)元對(duì)氣味信息是如何反應(yīng)和編碼的。
哺乳動(dòng)物的嗅皮層直接接受來(lái)之嗅球的信息,，并被認(rèn)為是形成氣味感知的重要部位,，但現(xiàn)在還不清楚嗅皮層神經(jīng)元是如何編碼和表征氣味信息的。本文通過(guò)對(duì)清醒動(dòng)物的嗅皮層神經(jīng)元進(jìn)行細(xì)胞外記錄,，研究了嗅皮層中單個(gè)神經(jīng)元對(duì)氣味是如何反應(yīng)的,。記錄完成后標(biāo)記出神經(jīng)元，并通過(guò)所標(biāo)記細(xì)胞的形態(tài),，以及神經(jīng)遞質(zhì)特性把記錄的細(xì)胞分為主神經(jīng)元以及不同類(lèi)型的中間神經(jīng)元,。本文作者發(fā)現(xiàn)嗅皮層神經(jīng)元對(duì)氣味信息有著非常不同的選擇性和反應(yīng)調(diào)諧特性,。在嗅皮層上,，大約有1/4的主神經(jīng)元可以被分子結(jié)構(gòu)不同的氣味廣泛激活，有1/4的主神經(jīng)元被分子結(jié)構(gòu)不同的氣味廣泛抑制,，而其他約1/2的主神經(jīng)元對(duì)實(shí)驗(yàn)中用到的大部分氣味沒(méi)有任何反應(yīng),，有非常高的氣味選擇性。我們還發(fā)現(xiàn)GABA神經(jīng)元對(duì)實(shí)驗(yàn)中用到的氣味選擇性較低,，且很少會(huì)被氣味抑制,。其他非GABA的中間神經(jīng)元?jiǎng)t被許多氣味強(qiáng)烈抑制?？偟膩?lái)說(shuō),，這些數(shù)據(jù)顯示在清醒小鼠的嗅皮層上氣味信息是被眾多選擇性不同的神經(jīng)元表征和編碼的，這些反應(yīng)調(diào)諧曲線不同的神經(jīng)元也許在氣味感知和編碼中發(fā)揮著不同的作用,。
本文的第一作者為占成,，通訊作者為羅敏敏。此項(xiàng)研究由科技部863及973計(jì)劃及北京市科委資助,，在北京生命科學(xué)研究所完成,。（生物谷Bioon.com）
生物谷推薦原文出處：
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: [email protected]
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.
