Gamma-Aminobuyric Acid (GABA)-Mediated Neural Connections in the Drosophila Antennal Lobe
Gamma-Aminobuyric Acid (GABA)-Mediated Neural Connections in the Drosophila Antennal Lobe
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DOI：
10.1002/cne.21971
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发表时间：
2009-05-01
影响因子：
2.5
通讯作者：
Ito, Kei
中科院分区：
文献类型：
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作者：
Okada, Ryuichi;Awasaki, Takeshi;Ito, Kei
由γ-氨基丁酸（GABA）介导的抑制性突触连接在脑的神经计算中起着重要作用。为了获得GABA信号介导的神经连接的详细概述，我们分析了果蝇成年大脑中产生和接收GABA的细胞的分布。相对少量的细胞在大脑的几个区域形成簇，表达GABA合成酶Gad 1。另一方面，散布在脑中的许多细胞表达离子型GABA（A）受体亚单位（Lcch 3和Rdl）和代谢型GABA（B）受体亚型（GABA-B-R1、-2和-3）。为了分析这些基因在不同的细胞类型中的表达，我们集中在触角叶，其中GABA能神经元在气味编码中起重要作用。通过结合荧光原位杂交和免疫标记对GFP表达与细胞类型特异性GAL 4驱动菌株，我们量化的百分比，产生或接收GABA的细胞为每种细胞类型。GABA的合成中触角脑束（mACT）投射神经元和两种类型的本地神经元。其中，mACT神经元在触角叶中几乎没有突触前位点，使得局部神经元基本上是GABA信号的唯一提供者。另一方面，不仅这些局部神经元，而且所有类型的投射神经元都表达亲离子型和亲代谢型GABA受体。因此，即使抑制信号仅从少数特定类型的局部神经元释放，信号也被触角叶神经回路中的大多数神经元读取。神经学比较杂志514：74-91，2009. (c)2009 Wiley-Liss，Inc.
Inhibitory synaptic connections mediated by gamma-aminobutyric acid (GABA) play important roles in the neural computation of the brain. To obtain a detailed overview of the neural connections mediated by GABA signals, we analyzed the distribution of the cells that produce and receive GABA in the Drosophila adult brain. Relatively small numbers of the cells, which form clusters in several areas of the brain, express the GABA synthesis enzyme Gad1. On the other hand, many cells scattered across the brain express ionotropic GABA(A) receptor subunits (Lcch3 and Rdl) and metabotropic GABA(B) receptor subtypes (GABA-B-R1, -2, and -3). To analyze the expression of these genes in distinct identified cell types, we focused on the antennal lobe, where GABAergic neurons play important roles in odor coding. By combining fluorescent in situ hybridization and immunolabeling against GFP expressed with cell-type-specific GAL4 driver strains, we quantified the percentage of the cells that produce or receive GABA for each cell type. GABA was synthesized in the middle antennocerebral tract (mACT) projection neurons and two types of local neurons. Among them, mACT neurons had few presynaptic sites in the antennal lobe, making the local neurons essentially the sole provider of GABA signals there. On the other hand, not only these local neurons but also all types of projection neurons expressed both ionotropic and metabotropic GABA receptors. Thus, even though inhibitory signals are released from only a few, specific types of local neurons, the signals are read by most of the neurons in the antennal lobe neural circuitry. J. Comp. Neurol. 514:74-91, 2009. (c) 2009 Wiley-Liss, Inc.