EphA4 Signaling in Juveniles Establishes Topographic Specificity of Structural Plasticity in the Hippocampus
EphA4 Signaling in Juveniles Establishes Topographic Specificity of Structural Plasticity in the Hippocampus
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DOI：
10.1016/j.neuron.2010.02.016
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发表时间：
2010-03-11
期刊：
影响因子：
16.2
通讯作者：
Caroni, Pico
中科院分区：
文献类型：
--
作者：
Galimberti, Ivan;Bednarek, Ewa;Caroni, Pico
突触的形成和丧失与学习和记忆有关。成人大脑中共存着不同的永久性突触和可塑性突触亚群，但建立这些区别的原理和机制尚不清楚。在这里，我们显示在海马体中，具有高可塑性的终末分支(TA)在幼年阶段被指定，并解释了成年苔藓纤维的大部分突触更新。在沿着CA3的9-12个巨型终末中，由小鼠报告线显示的不同的颗粒神经元亚群显示为0、1或>；2Tas。TA规范涉及基于细胞体位置和EphA4信号的地形规则。当幼年回路中的EphA4信号或PSA-NCAM中断时，单TA苔藓纤维形成>；2 TA，提示轴突内竞争影响可塑性部位的选择。因此，青少年的可塑性突触规范定义了成年突触重塑的位置，而海马回路的可塑性遵循意想不到的地形图原理。
The formation and loss of synapses is involved in learning and memory. Distinct subpopulations of permanent and plastic synapses coexist in the adult brain, but the principles and mechanisms underlying the establishment of these distinctions remain unclear. Here we show that in the hippocampus, terminal arborizations (TAs) with high plasticity properties are specified at juvenile stages, and account for most synapse turnover of adult mossy fibers. Out of 9-12 giant terminals along CA3, distinct subpopulations of granule neurons revealed by mouse reporter lines exhibit 0, 1, or >2 TAs. TA specification involves a topographic rule based on cell body position and EphA4 signaling. Upon disruption of EphA4 signaling or PSA-NCAM in juvenile circuits, single-TA mossy fibers establish >2 TAs, suggesting that intraaxonal competition influences plasticity site selection. Therefore, plastic synapse specification in juveniles defines sites of synaptic remodeling in the adult, and hippocampal circuit plasticity follows unexpected topographic principles.