Circuit topology for synchronizing neurons in spontaneously active networks
Circuit topology for synchronizing neurons in spontaneously active networks
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DOI：
10.1073/pnas.0914594107
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发表时间：
2010-06-01
影响因子：
11.1
通讯作者：
Ikegaya, Yuji
中科院分区：
文献类型：
--
作者：
Takahashi, Naoya;Sasaki, Takuya;Ikegaya, Yuji
尖峰同步是大脑信息处理和存储的基础。但是神经元如何在嘈杂的网络中同步呢？通过利用高速（500- 2，000 fps）多神经元成像技术和大规模突触映射方法，我们直接比较了海马CA 3网络的自发活动模式和解剖连接。与未连接的神经元对相比，突触耦合的神经元共享更常见的突触前神经元，接收更多相关的兴奋性突触输入，并以大约107倍的概率发出同步尖峰。重要的是，共同的突触前父母本身同步比非共享上游神经元。与此一致，动态钳刺激显示，共同的输入单独不能占现实程度的同步，除非突触前尖峰之间的共同父母同步。在宏观尺度上，网络活动是由同步的幂律缩放来协调的，它涉及不同的密集互连（因此高度同步）的神经元组。因此，局部相干活动收敛于特定的细胞组件，从而产生复杂的系综动力学。这些分段同步的脉冲分组可以用作在关联并行网络信道中流动的信息模块。
Spike synchronization underlies information processing and storage in the brain. But how can neurons synchronize in a noisy network? By exploiting a high-speed (500-2,000 fps) multineuron imaging technique and a large-scale synapse mapping method, we directly compared spontaneous activity patterns and anatomical connectivity in hippocampal CA3 networks ex vivo. As compared to unconnected pairs, synaptically coupled neurons shared more common presynaptic neurons, received more correlated excitatory synaptic inputs, and emitted synchronized spikes with approximately 107 times higher probability. Importantly, common presynaptic parents per se synchronized more than unshared upstream neurons. Consistent with this, dynamic-clamp stimulation revealed that common inputs alone could not account for the realistic degree of synchronization unless presynaptic spikes synchronized among common parents. On a macroscopic scale, network activity was coordinated by a power-law scaling of synchronization, which engaged varying sets of densely interwired (thus highly synchronized) neuron groups. Thus, locally coherent activity converges on specific cell assemblies, thereby yielding complex ensemble dynamics. These segmentally synchronized pulse packets may serve as information modules that flow in associatively parallel network channels.