Properties of external plexiform layer interneurons in mouse olfactory bulb slices
Properties of external plexiform layer interneurons in mouse olfactory bulb slices
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DOI：
10.1016/j.neuroscience.2005.03.008
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发表时间：
2005-01-01
期刊：
影响因子：
3.3
通讯作者：
Hayar, A
中科院分区：
文献类型：
--
作者：
Hamilton, KA;Heinbockel, T;Hayar, A
在主嗅球的外丛状层（EPL）中，抑制颗粒细胞的顶端树突与二尖瓣细胞和簇状细胞（M/T）形成大量的突触，这些突触调节着活性沿M/T细胞树突的传播。EPL还包含内在的中间神经元，其功能尚不清楚。本研究对小鼠嗅球切片EPL的细胞体进行了记录。生物细胞素填充证实记录的细胞包括中间神经元、簇状细胞和星形胶质细胞。中间的神经元有细小的、静脉曲张的树突，位于几个相邻肾小球下面的浅表的树突桥接EPL间隙。神经元间活动以高频自发兴奋突触后电位/电流为特征，这些电位/电流被α -氨基-3-羟基-5-甲基异恶唑-4-丙酸(AMPA)/海苷酸受体拮抗剂6-氰基-7-硝基喹啉-2,3-二酮阻断，并被电压敏感的Na+通道阻滞剂河蟹毒素消除。神经元间活动与簇状细胞明显不同，簇状细胞通常表现出自发的动作电位爆发。中间神经元自发产生的动作电位很少，但经常在去极化和/或嗅神经（ON）刺激下产生动作电位。去极化的反应类似于在其他皮质区域发现的晚期和快速尖峰中间神经元的反应。on诱发反应的潜伏期和变异性表明存在多突触输入。在小鼠谷氨酸脱羧酶65启动子控制下，表达绿色荧光蛋白的中间神经元表现出相同的特性，证明EPL中间神经元具有gaba能。总之，这些结果表明EPL中间神经元通过AMPA/kainate受体被M/T细胞激活，并可能反过来抑制与几个相邻肾小球在地形上相关的空间域内的M/T细胞。(c) 2005年由Elsevier Ltd代表IBRO出版。
In the external plexiform layer (EPL) of the main olfactory bulb, apical dendrites of inhibitory granule cells form large numbers of synapses with mitral and tufted (M/T) cells, which regulate the spread of activity along the M/T cell dendrites. The EPL also contains intrinsic interneurons, the functions of which are unknown. In the present study, recordings were obtained from cell bodies in the EPL of mouse olfactory bulb slices. Biocytin-filling confirmed that the recorded cells included interneurons, tufted cells, and astrocytes. The interneurons had fine, varicose dendrites, and those located superficially bridged the EPL space below several adjacent glomeruli. Interneuron activity was characterized by high frequency spontaneous excitatory postsynaptic potential/currents that were blocked by the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione and largely eliminated by the voltage-sensitive Na+ channel blocker, tetrodotoxin. Interneuron activity differed markedly from that of tufted cells, which usually exhibited spontaneous action potential bursts. The interneurons produced few action potentials spontaneously, but often produced them in response to depolarization and/or olfactory nerve (ON) stimulation. The responses to depolarization resembled responses of late- and fast-spiking interneurons found in other cortical regions. The latency and variability of the ON-evoked responses were indicative of polysynaptic input. Interneurons expressing green fluorescent protein under control of the mouse glutamic acid decarboxylase 65 promoter exhibited identical properties, providing evidence that the EPL interneurons are GABAergic. Together, these results suggest that EPL interneurons are excited by M/T cells via AMPA/kainate receptors and may in turn inhibit M/T cells within spatial domains that are topographically related to several adjacent glomeruli. (c) 2005 Published by Elsevier Ltd on behalf of IBRO.