Principles of long-term dynamics of dendritic spines.
Principles of long-term dynamics of dendritic spines.
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DOI：
10.1523/jneurosci.0603-08.2008
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发表时间：
2008-12-10
期刊：
影响因子：
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通讯作者：
Kasai H
中科院分区：
文献类型：
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作者：
Yasumatsu N;Matsuzaki M;Miyazaki T;Noguchi J;Kasai H
突触强度的长时程增强（LTP）需要大脑锥体神经元上树突棘的扩大。长期抑郁症（LTD）与脊柱萎缩有关。事实上，脊柱是动态结构：它们形成，改变其形状和体积，或者可以在几个小时内消失。所有这些变化都是由突触活动引起的，还是有些变化是由内在过程引起的？脊柱的扩大和收缩与脊柱的消除和生成有何关系？这些过程如何影响脊柱体积的稳定分布？为了回答这些问题，我们记录了许多个人的脊柱，每天数天，使用双光子成像的CA1锥体神经元在培养的大鼠海马切片出生后第17天至23天。在正常的突触传递中，棘通常会改变体积或产生或消除，从而显示出活动依赖的可塑性。然而，我们发现，即使在我们阻断突触活动之后，棘的体积也会发生变化，这反映了这些小结构在长期内的天然不稳定性。这种“内在波动”表现出独特的依赖脊柱体积。根据这些数据和随机波动理论建立的数学模型解释了棘的种群行为，如消除和生成速率，体积的稳定分布和大棘的长期持续性。我们的研究发现，脊柱的产生和消除比以前认为的更普遍，脊柱体积与其年龄和预期寿命显着相关。棘突的种群动态也可以预测记忆的关键心理特征。
Long-term potentiation (LTP) of synapse strength requires enlargement of dendritic spines on cerebral pyramidal neurons. Long-term depression (LTD) is linked to spine shrinkage. Indeed, spines are dynamic structures: they form, change their shapes and volumes or can disappear in the space of hours. Do all such changes result from synaptic activity, or do some changes result from intrinsic processes? How do enlargement and shrinkage of spines relate to elimination and generation of spines, and how do these processes contribute to the stationary distribution of spine volumes? To answer these questions, we recorded the volumes of many individual spines daily for several days using two-photon imaging of CA1 pyramidal neurons in cultured slices of rat hippocampus between postnatal day 17 to 23. With normal synaptic transmission, spines often changed volume or were created or eliminated, thereby showing activity-dependent plasticity. However, we found that spines changed volume even after we blocked synaptic activity, reflecting a native instability of these small structures over the long term. Such “intrinsic fluctuations” showed unique dependence on spine volume. A mathematical model constructed from these data and the theory of random fluctuations explains population behaviors of spines, such as rates of elimination and generation, stationary distribution of volumes and the long-term persistence of large spines. Our study finds that generation and elimination of spines are more prevalent than previously believed, and spine volume shows significant correlation with its age and life expectancy. The population dynamics of spines also predict key psychological features of memory.