Mitral and tufted cells differ in the decoding manner of odor maps in the rat olfactory bulb
Mitral and tufted cells differ in the decoding manner of odor maps in the rat olfactory bulb
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DOI：
10.1152/jn.01266.2003
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发表时间：
2004-06-01
影响因子：
2.5
通讯作者：
Mori, K
中科院分区：
文献类型：
--
作者：
Nagayama, S;Takahashi, YK;Mori, K
哺乳动物嗅球中的僧帽细胞和簇状细胞是嗅球的主要神经元，每种细胞的树突和轴突的投射方式不同。形态上的差异表明，僧帽细胞和簇状细胞在功能上是不同的，可以处理不同方面的嗅觉信息。为了研究这种可能性，我们记录了气味诱发的尖峰反应，从二尖瓣和中间簇状细胞中的脂肪酸，并在大鼠嗅球的背内侧部分的反应簇。脂肪酸和醛的Homestrans系列用于气味刺激。在响应足够的气味，二尖瓣细胞表现出相对较低的放电率尖峰响应，而中间簇状细胞响应较高的放电率。检查的分子感受范围（MRR）表明，大多数二尖瓣细胞表现出强大的抑制MRR，而大多数的中间簇状细胞没有或只有弱的抑制MRR。此外，结构上不同的气味，激活相邻的集群抑制尖峰活动的二尖瓣细胞，而他们造成没有或只有微弱的抑制在中间簇状细胞。此外，二尖瓣细胞的反应，以足够的兴奋性气味剂大大抑制混合的气味剂与其他气味剂，激活邻近的肾小球。与此相反，气味剂，激活邻近肾小球没有显着抑制反应的中间簇状细胞足够的兴奋性气味。这些结果表明，在解码肾小球气味图的方式二尖瓣和中间簇状细胞之间有明显的差异。
Mitral and tufted cells in the mammalian olfactory bulb are principal neurons, each type having distinct projection pattern of their dendrites and axons. The morphological difference suggests that mitral and tufted cells are functionally distinct and may process different aspects of olfactory information. To examine this possibility, we recorded odorant-evoked spike responses from mitral and middle tufted cells in the aliphatic acid- and aldehyde-responsive cluster at the dorsomedial part of the rat olfactory bulb. Homologous series of aliphatic acids and aldehydes were used for odorant stimulation. In response to adequate odorants, mitral cells showed spike responses with relatively low firing rates, whereas middle tufted cells responded with higher firing rates. Examination of the molecular receptive range (MRR) indicated that most mitral cells exhibited a robust inhibitory MRR, whereas a majority of middle tufted cells showed no or only a weak inhibitory MRR. In addition, structurally different odorants that activated neighboring clusters inhibited the spike activity of mitral cells, whereas they caused no or only a weak inhibition in the middle tufted cells. Furthermore, responses of mitral cells to an adequate excitatory odorant were greatly inhibited by mixing the odorant with other odorants that activated neighboring glomeruli. In contrast, odorants that activated neighboring glomeruli did not significantly inhibit the responses of middle tufted cells to the adequate excitatory odorant. These results indicate a clear difference between mitral and middle tufted cells in the manner of decoding the glomerular odor maps.