Inhibitory Gating of Input Comparison in the CA1 Microcircuit
Inhibitory Gating of Input Comparison in the CA1 Microcircuit
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DOI：
10.1016/j.neuron.2015.08.025
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发表时间：
2015-09-23
期刊：
影响因子：
16.2
通讯作者：
Magee, Jeffrey C.
中科院分区：
文献类型：
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作者：
Milstein, Aaron D.;Bloss, Erik B.;Magee, Jeffrey C.
突触输入的空间和时间特征涉及多个尺度的整合机制，包括突触前释放位点、突触后树突和抑制性中间神经元网络。在这里，我们研究这些机制如何合作过滤海马 CA1 区的突触输入。来自 CA1 锥体神经元的树突记录显示，由于前馈抑制，来自 CA3 的近端输入以及来自内嗅皮层 III 层 (ECIII) 的远端输入在低放电率下亚线性或线性求和，但由于突触促进在高放电率下超线性求和，产生高通滤波器。然而，在 ECIII 和 CA3 输入比较期间，超线性树突整合通过前馈和反馈抑制动态平衡，从而抑制树突复合体尖峰。我们发现表达神经肽 Y (NPY) 的 CA1 中间神经元的特定亚群通过整合 ECIII 和 CA3 输入通路并有效抑制 CA1 锥体神经元树突，对这种动态过滤器做出了显着贡献。
Spatial and temporal features of synaptic inputs engage integration mechanisms on multiple scales, including presynaptic release sites, postsynaptic dendrites, and networks of inhibitory interneurons. Here we investigate how these mechanisms cooperate to filter synaptic input in hippocampal area CA1. Dendritic recordings from CA1 pyramidal neurons reveal that proximal inputs from CA3 as well as distal inputs from entorhinal cortex layer III (ECIII) sum sublinearly or linearly at low firing rates due to feedforward inhibition, but sum supralinearly at high firing rates due to synaptic facilitation, producing a high-pass filter. However, during ECIII and CA3 input comparison, supralinear dendritic integration is dynamically balanced by feedforward and feedback inhibition, resulting in suppression of dendritic complex spiking. We find that a particular subpopulation of CA1 interneurons expressing neuropeptide Y (NPY) contributes prominently to this dynamic filter by integrating both ECIII and CA3 input pathways and potently inhibiting CA1 pyramidal neuron dendrites.