Distinct deep short-axon cell subtypes of the main olfactory bulb provide novel intrabulbar and extrabulbar GABAergic connections.
Distinct deep short-axon cell subtypes of the main olfactory bulb provide novel intrabulbar and extrabulbar GABAergic connections.
复制标题
DOI：
10.1523/jneurosci.2490-08.2008
复制
发表时间：
2008-08-13
期刊：
影响因子：
--
通讯作者：
Nusser Z
中科院分区：
文献类型：
--
作者：
Eyre MD;Antal M;Nusser Z
神经元微回路的一个普遍特征是gaba能中间神经元的存在，这些中间神经元控制谷氨酸能主细胞的活动和彼此之间的活动。在大鼠主嗅球（MOB）中，gaba能颗粒和肾小球周围细胞支配二尖瓣细胞和簇状细胞，但其自身抑制的来源尚不清楚。在这里，我们使用结合电生理和形态学的方法来研究相当神秘的细胞群的MOB。二尖瓣下层的深短轴突细胞（dSACs）是gaba能细胞，在球茎的各个层中具有广泛和特征性的轴突分支，基于无监督聚类分析揭示了三种不同的亚型。每种dSAC亚型表现出不同的电学性质，但接受相似的gaba能和谷氨酸能输入。所有dSAC亚型的局部轴突末端选择性地支配GABAA能颗粒和肾小球周围细胞，并诱导GABAA受体介导的ipsc。dsac的一个亚群（GL-dSAC）产生了一种新颖的球内投影，从深部到浅层。另一个亚群（GCL-dSAC）通过注入高嗅觉区域的逆行运输荧光微球进行标记，构成了一种新的MOB投影细胞群。我们的研究结果揭示了多种dSAC亚型，每种亚型都通过选择性地支配gaba能中间神经元来影响MOB活动，并为新的球内和球外gaba能投射提供了直接证据。
A universal feature of neuronal microcircuits is the presence of GABAergic interneurons that control the activity of glutamatergic principal cells and each other. In the rat main olfactory bulb (MOB), GABAergic granule and periglomerular cells innervate mitral and tufted cells, but the source of their own inhibition remains elusive. Here we used a combined electrophysiological and morphological approach to investigate a rather mysterious cell population of the MOB. Deep short-axon cells (dSACs) of the infra-mitral layers are GABAergic and have extensive and characteristic axonal ramifications in various layers of the bulb, based on which unsupervised cluster analysis revealed three distinct subtypes. Each dSAC subtype exhibits different electrical properties, but receives similar GABAergic and glutamatergic inputs. The local axon terminals of all dSAC subtypes selectively innervate GABAergic granule and periglomerular cells and evoke GABAA receptor-mediated IPSCs. One subpopulation of dSACs (GL-dSAC) creates a novel intrabulbar projection from deep to superficial layers. Another subpopulation (GCL-dSAC) is labeled by retrogradely-transported fluorescent microspheres injected into higher olfactory areas, constituting a novel projection-cell population of the MOB. Our results reveal multiple dSAC subtypes, each specialized to influence MOB activity by selectively innervating GABAergic interneurons, and provide direct evidence for novel intra- and extrabulbar GABAergic projections.