Functional selectivity and specific connectivity of inhibitory neurons in primary visual cortex
Functional selectivity and specific connectivity of inhibitory neurons in primary visual cortex
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初级视觉皮层抑制性神经元的功能选择性和特异性连接
DOI：
10.1101/294835
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
T. Mrsic
中科院分区：
文献类型：
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作者：
Petr Znamenskiy;Mean;D. Muir;M. Iacaruso;S. Hofer;T. Mrsic
在大脑皮层中，兴奋性和抑制性突触输入的相互作用塑造了神经元对感觉刺激的反应，稳定了网络动态1并提高了神经代码的效率和鲁棒性2 -4。兴奋性神经元接收跟踪兴奋的抑制性输入5 -8。然而，这种兴奋和抑制的协同调节是如何通过皮层回路实现的尚不清楚，因为抑制性中间神经元被认为汇集了附近兴奋性细胞的输入，并为它们提供与局部网络活动成比例的非特异性抑制9 -13。在这里，我们表明，虽然小白蛋白表达（PV）抑制细胞在小鼠初级视觉皮层与附近的锥体细胞的大多数连接，其突触连接的强度是根据细胞的反应的相似性。单个PV细胞强烈抑制那些为它们提供强烈兴奋并分享它们的视觉选择性的锥体细胞。突触权重的这种微调支持对个体锥体细胞的抑制性和兴奋性输入的共调谐，尽管抑制性和兴奋性神经元之间存在密集连接。我们的研究结果表明，个别光伏电池优先集成到子网络的相互连接，共同调整的锥体细胞，稳定其经常性的动态。相反，子网络之间弱但密集的抑制连接足以支持它们之间的竞争，使它们的输出去相关。我们认为，历史和结构的相关发射调整的重量抑制性和兴奋性连接，支持稳定的放大和选择性招聘的皮层子网络。
In the cerebral cortex, the interaction of excitatory and inhibitory synaptic inputs shapes the responses of neurons to sensory stimuli, stabilizes network dynamics1 and improves the efficiency and robustness of the neural code2–4. Excitatory neurons receive inhibitory inputs that track excitation5–8. However, how this co-tuning of excitation and inhibition is achieved by cortical circuits is unclear, since inhibitory interneurons are thought to pool the inputs of nearby excitatory cells and provide them with non-specific inhibition proportional to the activity of the local network9–13. Here we show that although parvalbumin-expressing (PV) inhibitory cells in mouse primary visual cortex make connections with the majority of nearby pyramidal cells, the strength of their synaptic connections is structured according to the similarity of the cells’ responses. Individual PV cells strongly inhibit those pyramidal cells that provide them with strong excitation and share their visual selectivity. This fine-tuning of synaptic weights supports co-tuning of inhibitory and excitatory inputs onto individual pyramidal cells despite dense connectivity between inhibitory and excitatory neurons. Our results indicate that individual PV cells are preferentially integrated into subnetworks of inter-connected, co-tuned pyramidal cells, stabilising their recurrent dynamics. Conversely, weak but dense inhibitory connectivity between subnetworks is sufficient to support competition between them, de-correlating their output. We suggest that the history and structure of correlated firing adjusts the weights of both inhibitory and excitatory connections, supporting stable amplification and selective recruitment of cortical subnetworks.