NMDA spikes enhance action potential generation during sensory input
NMDA spikes enhance action potential generation during sensory input
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DOI：
10.1038/nn.3646
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发表时间：
2014-03-01
影响因子：
25
通讯作者：
Larkum, Matthew E.
中科院分区：
文献类型：
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作者：
Palmer, Lucy M.;Shai, Adam S.;Larkum, Matthew E.
最近的体外实验表明，锥体神经元的簇状树突能够引起局部NMDA受体依赖的电发生，即所谓的NMDA峰。然而，到目前为止，证明它们在体内的存在是困难的。此外，NMDA锋电位是否与锥体神经元的输出有关尚不清楚。我们发现，在自发和感觉输入后，第2/3层锥体神经元簇状树突中均出现局部NMDA锋电位，并对输出动作电位的数量有很大影响。使用双光子激活的细胞内笼状NMDA受体拮抗剂（TC-MK 801），我们发现，孤立的NMDA尖峰通常发生在多个分支同时和感觉刺激大大增加其概率。我们的研究结果表明，NMDA受体在耦合2/3层锥体神经元的簇区域的细胞体，增强第1层输入的有效性具有重要的作用。
Recent evidence in vitro suggests that the tuft dendrites of pyramidal neurons are capable of evoking local NMDA receptor-dependent electrogenesis, so-called NMDA spikes. However, it has so far proved difficult to demonstrate their existence in vivo. Moreover, it is not clear whether NMDA spikes are relevant to the output of pyramidal neurons. We found that local NMDA spikes occurred in tuft dendrites of layer 2/3 pyramidal neurons both spontaneously and following sensory input, and had a large influence on the number of output action potentials. Using two-photon activation of an intracellular caged NMDA receptor antagonist (tc-MK801), we found that isolated NMDA spikes typically occurred in multiple branches simultaneously and that sensory stimulation substantially increased their probability. Our results demonstrate that NMDA receptors have a vital role in coupling the tuft region of the layer 2/3 pyramidal neuron to the cell body, enhancing the effectiveness of layer 1 input.