Expression and function of kainate receptors in the rat olfactory bulb.
Expression and function of kainate receptors in the rat olfactory bulb.
复制标题
大鼠嗅球中红藻氨酸受体的表达和功能。
DOI：
10.1002/syn.20376
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Trombley,PaulQ
中科院分区：
文献类型：
--
作者：
Davila,NestorG;Houpt,ThomasA;Trombley,PaulQ
虽然最近的研究结果表明NMDA和AMPA受体在气味编码中起作用，但对嗅球(OB)中的海人酸受体(KARs)知之甚少。分子、免疫学和电生理学技术被用来提供OB中KARs的功能分析。逆转录聚合酶链式反应显示KAR亚基的相对表达水平为GluR5、≈、GluR6、≈、Ka2&Gt；KA1、≫、GluR7。原位杂交结果表明，二尖瓣/簇状细胞主要表达GluR5和Ka2，而中间神经元主要表达GluR6和Ka2。免疫组织化学双标记实验(GluR5/6/7或GluR5+突触素)表明，Kars在突触和突触外的位置都有表达。KAR亚基的这种异质性表达表明，KAR可能在气味处理中扮演多种角色，每个角色都根据特定的OB回路的功能而定制。使用全细胞电生理学的功能分析表明，其中一个作用是增加谷氨酸传递的频率，同时减弱个别事件的幅度，可能是通过突触前去极化机制。这种影响对气味处理很重要，特别是对OB肾小球的影响。在这些高度区域化的结构中，谷氨酸释放频率的增加和由溢出激活的高密度突触外KARs可以增强肾小球的同步性，从而将更具体的感觉信息转移到皮质结构。Synapse 61：320-334,2007。©2007 Wiley-Liss Inc.
Although recent results suggest roles for NMDA and AMPA receptors in odor encoding, little is known about kainate receptors (KARs) in the olfactory bulb (OB). Molecular, immunological, and electrophysiological techniques were used to provide a functional analysis of KARs in the OB. Reverse transcriptase‐polymerase chain reaction revealed that the relative level of expression of KAR subunits was GluR5 ≈ GluR6 ≈ KA2 > KA1 ≫ GluR7. In situ hybridization data imply that mitral/tufted cells express mostly GluR5 and KA2, whereas interneurons express mostly GluR6 and KA2. Immunohistochemical double‐labeling experiments (GluR5/6/7 or GluR5 + synapsin) suggest that KARs are expressed at both synaptic and extrasynaptic loci. This heterogeneous expression of KAR subunits suggests that KARs may play a multitude of roles in odor processing, each tailored to the function of specific OB circuits. A functional analysis, using whole‐cell electrophysiology, suggests that one such role is to increase the frequency of glutamate transmission while attenuating the amplitude of individual events, likely via a presynaptic depolarizing mechanism. Such effects would be important to odor processing particularly by OB glomeruli. In these highly compartmentalized structures, an increase in the frequency of glutamate release and the high density of extrasynaptic KARs, activated by spillover, could enhance glomerular synchronization and thus the transfer of more specific sensory information to cortical structures. Synapse 61:320–334, 2007. © 2007 Wiley‐Liss, Inc.