ACTIVATION OF POSTSYNAPTICALLY SILENT SYNAPSES DURING PAIRING-INDUCED LTP IN CA1 REGION OF HIPPOCAMPAL SLICE
ACTIVATION OF POSTSYNAPTICALLY SILENT SYNAPSES DURING PAIRING-INDUCED LTP IN CA1 REGION OF HIPPOCAMPAL SLICE
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DOI：
10.1038/375400a0
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发表时间：
1995-06-01
期刊：
影响因子：
64.8
通讯作者：
MALINOW, R
中科院分区：
文献类型：
--
作者：
LIAO, DZ;HESSLER, NA;MALINOW, R
长期增强（LTP）是突触强度的增强，可通过突触前活动与突触后去极化配对产生（1）。海马中的LTP作为学习和记忆的细胞模型已被广泛研究，但潜在的突触修饰的性质仍然难以捉摸，部分原因是我们对中央突触的了解仍然有限（2，3）。一种观点认为这种修饰是突触后的，在增强作用之前只表达NMDA（N-甲基-D-天冬氨酸）受体的突触被LTP诱导表达功能性AMPA（α-氨基-3-羟基-5-甲基-4-异恶唑丙酸盐）受体。在这里，我们报告说，高比例的突触在海马区CAI传输与NMDA受体，但不AMPA受体，使这些突触有效地在正常的静息电位无功能。这些沉默突触在LTP诱导后获得AMPA型反应。我们的发现挑战了CA 1中LTP涉及突触前修饰的观点（6-10），并提出了LTP诱导和表达的简单突触后机制。
LONG-TERM potentiation (LTP) is an enhancement of synaptic strength that can be produced by pairing of presynaptic activity with postsynaptic depolarization(1). LTP in the hippocampus has been extensively studied as a cellular model of learning and memory, but the nature of the underlying synaptic modification remains elusive, partly because our knowledge of central synapses is still limited(2,3). One proposal(4,5) is that the modification is postsynaptic, and that synapses expressing only NMDA (N-methyl-D-aspartate) receptors before potentiation are induced by LTP to express functional AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionate) receptors. Here we report that a high proportion of synapses in hippocampal area CAI transmit with NMDA receptors but not AMPA receptors, making these synapses effectively non-functional at normal resting potentials. These silent synapses acquire AMPA-type responses following LTP induction, Our findings challenge the view(6-10) that LTP in CA1 involves a presynaptic modification, and suggest instead a simple postsynaptic mechanism for both induction and expression of LTP.