Persistence of excitatory shaft synapses adjacent to newly emerged dendritic protrusions.
Persistence of excitatory shaft synapses adjacent to newly emerged dendritic protrusions.
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DOI：
10.1016/j.mcn.2011.06.014
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发表时间：
2011-10
影响因子：
3.5
通讯作者：
Phillips, Greg R.
中科院分区：
文献类型：
--
作者：
Reilly, James E.;Hanson, Hugo H.;Phillips, Greg R.
关键词：
在出生后早期的海马中，兴奋性锥体神经元上出现的第一个突触直接在树突轴上形成。在这个时期，很少有树突棘。然而，到了成年期，绝大多数突触都位于树突棘的尖端。已经提出了几种模型来解释从主要是轴突触到主要是棘突触的过渡，但没有一个得到最终证明。为了研究轴-棘突触转换的细胞机制，我们设计了实时成像实验，直接观察发育树突上的轴和棘突触的动态。免疫荧光突触标记的GFP填充的神经元显示，在解离的培养镜像，在体内的轴到棘突触的过渡。沿着电子显微镜，荧光标记也显示，真正的轴突触是丰富的解离培养和轴突触经常邻近棘或其他树突状突起，以前在体内观察到的配置由他人。我们使用GFP填充的树突和VAMP 2-DsRed标记的终扣的实时长期延时共聚焦显微镜来记录轴突触和相关树突突起和终扣的命运，每小时拍摄图像长达31个连续小时。对延时成像系列的检查显示，轴突触可以持续存在于现有或新生长的树突状突起附近。或者，轴突触终接可以重新分布以接触相邻的树突突起。然而，我们从来没有观察到轴突触转化为棘或任何类型的树突突起。我们的结论是，反复迭代的树突突起或脊柱生长邻近轴突触是很可能是一个关键组成部分的轴到棘突触过渡在中枢神经系统的发展。
In the early postnatal hippocampus, the first synapses to appear on excitatory pyramidal neurons are formed directly on dendritic shafts. Very few dendritic spines are present at this time. By adulthood, however, the overwhelming majority of synapses are located at the tips of dendritic spines. Several models have been proposed to account for the transition from mostly shaft to mostly spinous synapses but none have been demonstrated conclusively. To investigate the cellular mechanism underlying the shaft-to-spinous synapse transition, we designed live imaging experiments to directly observe the dynamics of shaft and spinous synapses on developing dendrites. Immunofluorescent synaptic labeling of GFP-filled neurons showed that the shaft-to-spinous synapse transition in dissociated culture mirrors that in vivo. Along with electron microscopy, the fluorescent labeling also showed that veritable shaft synapses are abundant in dissociated culture and that shaft synapses are frequently adjacent to spines or other dendritic protrusions, a configuration previously observed in vivo by others. We used live long term time lapse confocal microscopy of GFP-filled dendrites and VAMP2-DsRed-labeled boutons to record the fate of shaft synapses and associated dendritic protrusions and boutons with images taken hourly for up to 31 continuous hours. Inspection of the time lapse imaging series revealed that shaft synapses can persist adjacent to either existing or newly grown dendritic protrusions. Alternatively, a shaft synapse bouton can redistribute to contact an adjacent dendritic protrusion. However, we never observed shaft synapses transforming themselves into spines or any type of dendritic protrusions. We conclude that repeated iterations of dendritic protrusion or spine outgrowth adjacent to shaft synapses is very likely to be a critical component of the shaft-to-spinous synapse transition during CNS development.
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DOI：
10.1111/j.1460-9568.2010.07386.x
发表时间：
2010-09
期刊：
The European journal of neuroscience
影响因子：
--
作者：
Fernández-Monreal M;Oung T;Hanson HH;O'Leary R;Janssen WG;Dolios G;Wang R;Phillips GR
通讯作者：
Phillips GR
影响因子：
5.3
作者：
Boyer, C;Schikorski, T;Stevens, CF
通讯作者：
Stevens, CF
影响因子：
64.8
作者：
Engert, F;Bonhoeffer, T
通讯作者：
Bonhoeffer, T
影响因子：
9.8
作者：
Lee WC;Huang H;Feng G;Sanes JR;Brown EN;So PT;Nedivi E
通讯作者：
Nedivi E
影响因子：
2.8
作者：
Hanson, Hugo H.;Reilly, James E.;Phillips, Greg R.
通讯作者：
Phillips, Greg R.