Populations of hippocampal inhibitory neurons express different levels of cytochrome c
Populations of hippocampal inhibitory neurons express different levels of cytochrome c
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DOI：
10.1111/j.1460-9568.2006.04814.x
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发表时间：
2006-05-01
影响因子：
3.4
通讯作者：
Hirase, Hajime
中科院分区：
文献类型：
--
作者：
Gulyas, Attila I.;Buzsaki, Gyorgy;Hirase, Hajime
细胞色素c （CC）免疫反应性定量在功能不同的大鼠海马抑制性神经元群体使用双免疫细胞化学和激光扫描共聚焦显微镜来测量CC表达水平以及细胞内线粒体的数量，这是神经元活动的一个标志。CC信号与细胞色素c氧化酶组织化学染色相似。体、树突和轴突末端云在低强度的神经pil染色上分散。染色呈颗粒状，电镜检查证实信号定位于线粒体。密集标记神经元主要分布在主细胞层、CA1-3区的东方层、透明层和门部，表现出抑制性细胞的形态特征。这些神经元不仅线粒体数量比主细胞多，而且线粒体染色强度也明显增强。在检测的神经元间群中，细小蛋白免疫反应神经元被密集地标记为CC， Calbindin D28k- (CB)、生长抑素和胆囊收缩素标记的细胞显示出不同的CC水平，而calretinin免疫反应细胞从未显示出强烈的CC信号。取向层和肺泡层、透明体和肺门的CB细胞被强烈标记为CC，已知这些区域的CB细胞投射到内侧隔膜并含有生长抑素。我们已经证明，投射到中隔的CA1中间神经元（海马-间隔神经元）表达高水平的CC，因此，与含有小蛋白的篮细胞和轴突-轴突细胞相似，海马-间隔神经元可能具有高的平均活动水平。
Cytochrome c (CC) immunoreactivity was quantified in functionally distinct rat hippocampal inhibitory neuron populations using double immunocytochemistry and laser scanning confocal microscopy to measure the CC expression level as well as the amount of mitochondria within the cells, which is a sign of neuronal activity. The CC signal showed a similar distribution to cytochrome c oxidase histochemical staining. Strongly stained somata, dendrites and axon terminal clouds were dispersed over the low intensity neuropil staining. The staining was granular and electron microscopic investigation confirmed that the signal was localized in mitochondria. Intensively labeled neurons, showing the morphological features of inhibitory cells, were most frequently found in the principal cell layers, stratum oriens of the CA1-3 areas, stratum lucidum and hilus. These neurons contained not only a higher number of mitochondria than the principal cells but the intensity of the mitochondrial staining was evidently stronger. Among the examined interneuronal populations, parvalbumin-immunoreactive neurons were intensively labeled for CC. Calbindin D28k- (CB), somatostatin- and cholecystokinin-labeled cells showed heterogeneous CC levels, whereas calretinin-immunoreactive cells never showed a strong CC signal. CB cells in stratum oriens and alveus layers, lucidum and the hilus were strongly labeled for CC. CB cells in such regions are known to project to the medial septum and contain somatostatin. We have demonstrated that the CA1 interneurons that project to the medial septum (hippocampo-septal neurons) express a high level of CC. Thus, similar to the parvalbumin-containing basket and axo-axonic cells, the hippocampo-septal neurons potentially have a high average activity level.