Activity maintains structural plasticity of mossy fiber terminals in the hippocampus
Activity maintains structural plasticity of mossy fiber terminals in the hippocampus
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DOI：
10.1016/j.mcn.2012.05.004
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发表时间：
2012-07-01
影响因子：
3.5
通讯作者：
Murai, Keith K.
中科院分区：
文献类型：
--
作者：
Chierzi, Sabrina;Stachniak, Tevye J.;Murai, Keith K.
神经活动在组织和优化发育期间和成熟神经系统中的神经回路方面起着重要作用。然而，这一过程背后的细胞事件仍有待完全理解。在这项研究中，我们调查的作用，神经活动在调节结构可塑性的突触前末梢在海马结构。我们设计了一种病毒来驱动果蝇Allatostatin受体在个别齿状颗粒神经元，以抑制活动的复杂苔藓纤维终端的器官型切片的“按需”，并使用延时共聚焦成像，以确定突触前重塑的影响。我们发现，活动发挥了重要作用，在维持苔藓纤维终端（MFT）的核心区域的结构可塑性，突触到CA3锥体细胞多刺的赘生物，但不是必不可少的终端丝状伪足的延伸，接触当地的抑制性神经元的运动。活动的短期抑制对MFT的大小没有影响，但是，长期抑制降低了MFT的总体大小。值得注意的是，河豚毒素（TTX）的活动的全球封锁干扰单细胞活动剥夺的能力，以减缓终端动态表明，在相邻的突触之间的活动水平的差异，促进突触重塑事件。我们的研究结果表明，神经活动在维持中枢神经系统突触前区室的结构可塑性方面起着重要作用，并为活动影响突触连接形态的时间框架提供了新的见解。(c)2012 Elsevier Inc. All rights reserved.
Neural activity plays an important role in organizing and optimizing neural circuits during development and in the mature nervous system. However, the cellular events that underlie this process still remain to be fully understood. In this study, we investigated the role of neural activity in regulating the structural plasticity of presynaptic terminals in the hippocampal formation. We designed a virus to drive the Drosophila Allatostatin receptor in individual dentate granule neurons to suppress activity of complex mossy fiber terminals 'on-demand' in organotypic slices and used time-lapse confocal imaging to determine the impact on presynaptic remodeling. We found that activity played an important role in maintaining the structural plasticity of the core region of the mossy fiber terminal (MFT) that synapses onto CA3 pyramidal cell thorny excrescences but was not essential for the motility of terminal filopodial extensions that contact local inhibitory neurons. Short-term suppression of activity did not have an impact on the size of the MFT, however, longer-term suppression reduced the overall size of the MFT. Remarkably, global blockade of activity with tetrodotoxin (TTX) interfered with the ability of single cell activity deprivation to slow down terminal dynamics suggesting that differences in activity levels among neighboring synapses promote synaptic remodeling events. The results from our studies indicate that neural activity plays an important role in maintaining structural plasticity of presynaptic compartments in the central nervous system and provide new insight into the time-frame during which activity can affect the morphology of synaptic connections. (c) 2012 Elsevier Inc. All rights reserved.