Excitatory cortical neurons form fine-scale functional networks
Excitatory cortical neurons form fine-scale functional networks
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DOI：
10.1038/nature03252
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发表时间：
2005-02-24
期刊：
影响因子：
64.8
通讯作者：
Callaway, EM
中科院分区：
文献类型：
--
作者：
Yoshimura, Y;Dantzker, JLM;Callaway, EM
皮质神经元连接的特异性产生了从软脑膜到白质的功能相似的神经元柱(1-6)。在这里，我们调查是否有额外的，更精细的特异性水平，在功能柱内创建兴奋性神经元子网络。我们通过光刺激诱发的突触电流的互相关分析，测试了与大鼠视皮层第2/3层锥体神经元连接的细微尺度特异性。从相邻的2/3层锥体细胞同时记录，我们发现当它们相互连接时(占所有记录对的20%)，它们共享来自第4层和第2/3层的共同输入。当相邻的第2/3层神经元彼此不连接时，它们共享来自第4层和第2/3层的共同兴奋性输入(如果有的话)。相反，所有第2/3层神经元共享来自第5层的共同兴奋性输入和来自第2/3层和第4层的抑制输入，无论它们是否彼此连接。因此，从第4层到第2/3层和第2/3层内的兴奋性连接形成了选择性相互连接的神经元的精细组合；来自第5层的抑制性连接和兴奋性连接跨越这些细微规模的子网络链接神经元。因此，相对独立的兴奋性神经元的子网络嵌入到更大规模的功能结构中；这使得邻近的神经元能够比先前对皮质电路的描述所建议的更独立地传递信息。
The specificity of cortical neuron connections creates columns of functionally similar neurons spanning from the pia to the white matter(1-6). Here we investigate whether there is an additional, finer level of specificity that creates subnetworks of excitatory neurons within functional columns. We tested for fine-scale specificity of connections to cortical layer 2/3 pyramidal neurons in rat visual cortex by using cross-correlation analyses of synaptic currents evoked by photostimulation. Recording simultaneously from adjacent layer 2/3 pyramidal cells, we find that when they are connected to each other (20% of all recorded pairs) they share common input from layer 4 and within layer 2/3. When adjacent layer 2/3 neurons are not connected to each other, they share very little ( if any) common excitatory input from layers 4 and 2/3. In contrast, all layer 2/3 neurons share common excitatory input from layer 5 and inhibitory input from layers 2/3 and 4, regardless of whether they are connected to each other. Thus, excitatory connections from layer 4 to layer 2/3 and within layer 2/3 form fine-scale assemblies of selectively interconnected neurons; inhibitory connections and excitatory connections from layer 5 link neurons across these fine-scale subnetworks. Relatively independent subnetworks of excitatory neurons are therefore embedded within the larger-scale functional architecture; this allows neighbouring neurons to convey information more independently than suggested by previous descriptions of cortical circuitry.