Institut de Neurobiologie de la Méditerranée INSERM U901, Universitéde la Méditerranée, Parc Scientifique de Luminy, Boîte Postale 13, 13273 Marseille Cedex 9, France.
Science. 2009 Dec 4;326(5958):1419-24. doi: 10.1126/science.1175509.
Brain function operates through the coordinated activation of neuronal assemblies. Graph theory predicts that scale-free topologies, which include "hubs" (superconnected nodes), are an effective design to orchestrate synchronization. Whether hubs are present in neuronal assemblies and coordinate network activity remains unknown. Using network dynamics imaging, online reconstruction of functional connectivity, and targeted whole-cell recordings in rats and mice, we found that developing hippocampal networks follow a scale-free topology, and we demonstrated the existence of functional hubs. Perturbation of a single hub influenced the entire network dynamics. Morphophysiological analysis revealed that hub cells are a subpopulation of gamma-aminobutyric acid-releasing (GABAergic) interneurons possessing widespread axonal arborizations. These findings establish a central role for GABAergic interneurons in shaping developing networks and help provide a conceptual framework for studying neuronal synchrony.
大脑功能通过神经元集合的协调激活来运作。图论预测，包括“枢纽”（超级连接节点）在内的无标度拓扑结构是协调同步的有效设计。神经元集合中是否存在枢纽以及协调网络活动仍然未知。使用网络动力学成像、功能连接的在线重建以及大鼠和小鼠的靶向全细胞记录，我们发现发育中的海马网络遵循无标度拓扑结构，并且我们证明了功能枢纽的存在。单个枢纽的干扰会影响整个网络动力学。形态生理学分析表明，枢纽细胞是释放γ-氨基丁酸的（GABAergic）中间神经元的一个亚群，具有广泛的轴突分支。这些发现确立了 GABAergic 中间神经元在塑造发育中的网络中的核心作用，并有助于为研究神经元同步提供一个概念框架。
