Regulation of dendritic spine motility in cultured hippocampal neurons
Regulation of dendritic spine motility in cultured hippocampal neurons
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DOI：
10.1523/jneurosci.21-16-06115.2001
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发表时间：
2001-08-15
影响因子：
5.3
通讯作者：
Segal, M
中科院分区：
文献类型：
--
作者：
Korkotian, E;Segal, M
使用绿色荧光蛋白标记的神经元或负载钙敏感染料 Oregon Green-1 的神经元，在大鼠和小鼠海马体的分离培养物中研究树突棘运动的调节。在共焦激光扫描显微镜上以高分辨率对细胞进行延时拍摄，以检测树突棘中的运动以及细胞内钙浓度的自发波动。附着在棘上的活跃突触前末梢被标记为 FM4-64，它标志着突触素标记末梢的一个子集。树突棘在 4 至 7 日龄的年轻细胞中具有高度活动性。在这个年龄，神经元几乎没有自发的钙波动或 FM4-64 标记。在培养 2-3 周内，树突棘的活动性大大降低，它们与活跃的突触前末梢相关，并且表达自发钙波动率很高。无论年龄如何，即使在相同的树突上，脊柱运动性与与成像脊柱接触的 FM4-64 标记终端的存在之间也存在反比关系。脊柱运动被 latrunculin 阻断，它可以防止肌动蛋白聚合，并且通过河豚毒素阻断动作电位放电来解除抑制。有人提出，活跃的突触前末梢限制了树突棘的运动。
Regulation of dendritic spine motility was studied in dissociated cultures of the rat and mouse hippocampus, using green fluorescent protein-labeled neurons or neurons loaded with the calcium-sensitive dye Oregon Green-1. Cells were time-lapse-photographed on a confocal laser-scanning microscope at high resolution to detect movements as well as spontaneous fluctuations of intracellular calcium concentrations in their dendritic spines. Active presynaptic terminals attached to the spines were labeled with FM4-64, which marks a subset of synaptophysin-labeled terminals. Dendritic spines were highly motile in young, 4- to 7-d-old cells. At this age, neurons had little spontaneous calcium fluctuation or FM4-64 labeling. Within 2-3 weeks in culture, dendritic spines were much less motile, they were associated with active presynaptic terminals, and they expressed high rates of spontaneous calcium fluctuations. Irrespective of age, and even on the same dendrite, there was an inverse relationship between spine motility and presence of FM4-64-labeled terminals in contact with the imaged spines. Spine motility was blocked by latrunculin, which prevents actin polymerization, and was disinhibited by blockade of action potential discharges with tetrodotoxin. It is proposed that an active presynaptic terminal restricts motility of dendritic spines.