ORGANIZATION OF MITOCHONDRIA IN OLFACTORY-BULB GRANULE CELL DENDRITIC SPINES
ORGANIZATION OF MITOCHONDRIA IN OLFACTORY-BULB GRANULE CELL DENDRITIC SPINES
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DOI：
10.1002/syn.890080205
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发表时间：
1991-06-01
期刊：
影响因子：
2.3
通讯作者：
GREER, CA
中科院分区：
文献类型：
--
作者：
CAMERON, HA;KALISZEWSKI, CK;GREER, CA
与只具有突触后功能的树突棘相反，嗅球颗粒细胞的棘同时具有突触前和突触后的作用。 在单个切片中，这些棘先前被发现含有线粒体，很可能需要为突触前功能提供能量，但它们的频率和分布尚不清楚。 为了了解这些专门的树突状附属物的线粒体的组织，我们研究了颗粒细胞棘的几何形状和细胞质组织与计算机辅助重建的系列电子显微照片。 棘头呈椭圆形，凹面上有一对相互突触，与二尖瓣/簇状细胞树突并列。 线粒体被发现位于脊柱颈部和脊柱头部，并且通常在两个隔室之间延伸。 基于它们的可变分布，似乎合理地表明这些线粒体是能动的，并且从母体树突移入和移出棘隔室。 棘器在大多数棘中是明显的，因为膜结合的滑面内质网位于线粒体附近。 在没有微管的情况下，棘器在促进颗粒细胞棘的颈部和头部的线粒体的运动中可能起的作用进行了讨论。
In contrast to dendritic spines with only postsynaptic functions, the spines of olfactory bulb granule cells subserve both pre- and postsynaptic roles. In single sections these spines were previously seen to contain mitochondria, most likely needed to provide energy for presynaptic functions, but their frequency and distribution were unknown. In order to understand the organization of mitochondria in these specialized dendritic appendages, we have studied the geometry and cytoplasmic organization of granule cell spines with computer-assisted reconstructions of serial electron micrographs. The spine heads were seen to be elliptical in shape with a single pair of reciprocal synapses on the concave face apposed to the mitral/tufted cell dendrite. Mitochondria were found localized in the spine neck as well as the spine head and often extended between the two compartments. Based on their variable distribution it seems reasonable to suggest that these mitochondria are motile and move in and out of spine compartments from the parent dendrite. Spine apparatus was apparent in most of the spines as membrane bound cisterns of smooth endoplasmic reticulum located close to mitochondria. The possible role of spine apparatus in facilitating the movement of mitochondria in the necks and heads of granule cell spines in the absence of microtubules is discussed.