Mossy Fiber-CA3 Synapses Mediate Homeostatic Plasticity in Mature Hippocampal Neurons
Mossy Fiber-CA3 Synapses Mediate Homeostatic Plasticity in Mature Hippocampal Neurons
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DOI：
10.1016/j.neuron.2012.10.033
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发表时间：
2013-01-09
期刊：
影响因子：
16.2
通讯作者：
Pak, Daniel T. S.
中科院分区：
文献类型：
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作者：
Lee, Kea Joo;Queenan, Bridget N.;Pak, Daniel T. S.
网络活动自稳地改变突触的效能，以限制神经元的输出。然而，目前还不清楚这种补偿性适应如何与突触信息存储共存，特别是在已建立的网络中。在此，我们报道了在体外成熟的海马神经元中，网络活动优先调节CA3神经元近端树突内的兴奋性突触。这些稳态突触表现出齿状颗粒细胞苔藓纤维和CA3锥体神经元的刺突(TES)之间的特殊接触的形态、功能和分子特征。在体内，TES也被慢性的活动改变选择性地和双向地改变。TE的形成需要突触前突触配基，并被活性诱导激酶PLK2抑制。这些结果暗示苔藓纤维-TE突触是一个独立可调的增益控制点，允许苔藓纤维-CA3突触有效的动态平衡调节，同时保留可能编码其他信息的突触重量-在成熟的海马体电路中。
Network activity homeostatically alters synaptic efficacy to constrain neuronal output. However, it is unclear how such compensatory adaptations coexist with synaptic information storage, especially in established networks. Here, we report that in mature hippocampal neurons in vitro, network activity preferentially regulated excitatory synapses within the proximal dendrites of CA3 neurons. These homeostatic synapses exhibited morphological, functional, and molecular signatures of the specialized contacts between mossy fibers of dentate granule cells and thorny excrescences (TEs) of CA3 pyramidal neurons. In vivo TEs were also selectively and bidi-rectionally altered by chronic,activity changes. TE formation required presynaptic synaptoporin and was suppressed by the activity-inducible kinase, Plk2. These results implicate the mossy fiber-TE synapse as an independently tunable gain control locus that permits efficacious homeostatic adjustment of mossy fiber-CA3 synapses, while preserving synaptic weights that may encode information else-where within the mature hippocampal circuit.