Mitral cells in the olfactory bulb are mainly excited through a multistep signaling path.
Mitral cells in the olfactory bulb are mainly excited through a multistep signaling path.
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嗅球中的二尖瓣细胞主要通过多步信号通路被激发。
DOI：
10.1523/jneurosci.5580-11.2012
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发表时间：
2012-02-29
期刊：
影响因子：
--
通讯作者：
Schoppa NE
中科院分区：
文献类型：
--
作者：
Gire DH;Franks KM;Zak JD;Tanaka KF;Whitesell JD;Mulligan AA;Hen R;Schoppa NE
在嗅觉系统中，信息从外周流向嗅球(OB)的输出二尖瓣细胞(MC)被认为是由来自嗅觉神经元(OSN)的直接突触输入所介导的。在这里，我们在大鼠和小鼠的OB切片上进行了膜片钳测量，以研究OSN向MC传递信号的机制，包括使用电和光遗传刺激方法选择性激活OSN的直接途径的假设。我们发现，MC实际上通常不是由直接的OSN输入激活的，而是需要一种涉及另一种谷氨酸能细胞类型--簇状细胞的多步骤扩散机制。对多步骤机制的偏好反映了这样一个事实，即来自直接OSN输入的信号被连接蛋白36介导的MC上的缝隙连接而不是丛生细胞显著地分流。在OSN和MC之间有簇状细胞的OB回路表明，嗅觉信息在到达MC之前进行了相当大的处理。
Within the olfactory system, information flow from the periphery onto output mitral cells (MCs) of the olfactory bulb (OB) has been thought to be mediated by direct synaptic inputs from olfactory sensory neurons (OSNs). Here, we performed patch-clamp measurements in rat and mouse OB slices to investigate mechanisms of OSN signaling onto MCs, including the assumption of a direct path, using electrical and optogenetic stimulation methods that selectively activated OSNs. We found that MCs are in fact not typically activated by direct OSN inputs and instead require a multistep, diffuse mechanism involving another glutamatergic cell-type, the tufted cells. The preference for a multi-step mechanism reflects the fact that signals arising from direct OSN inputs are drastically shunted by connexin 36-mediated gap junctions on MCs, but not tufted cells. An OB circuit with tufted cells intermediate between OSNs and MCs suggests that considerable processing of olfactory information occurs prior to it reaching MCs.