Bharmauria Vishal, Bachatene Lyes, Cattan Sarah, Chanauria Nayan, Rouat Jean, Molotchnikoff Stéphane
Neurophysiology of Visual System, Département de Sciences Biologiques, Université de Montréal, Succ. centre-ville, CP 6128, Montreal, QC, H3C 3J7, Canada.
Neurosciences Computationnelles et Traitement Intelligent des Signaux (NECOTIS), Sherbrooke, QC, Canada.
Exp Brain Res. 2016 Feb;234(2):523-32. doi: 10.1007/s00221-015-4482-7. Epub 2015 Nov 2.
Neural correlations (noise correlations and cross-correlograms) are widely studied to infer functional connectivity between neurons. High noise correlations between neurons have been reported to increase the encoding accuracy of a neuronal population; however, low noise correlations have also been documented to play a critical role in cortical microcircuits. Therefore, the role of noise correlations in neural encoding is highly debated. To this aim, through multi-electrodes, we recorded neuronal ensembles in the primary visual cortex of anaesthetized cats. By computing cross-correlograms, we divulged the functional network (microcircuit) between neurons within an ensemble in relation to a specific orientation. We show that functionally connected neurons systematically exhibit higher noise correlations than functionally unconnected neurons in a microcircuit that is activated in response to a particular orientation. Furthermore, the mean strength of noise correlations for the connected neurons increases steeply than the unconnected neurons as a function of the resolution window used to calculate noise correlations. We suggest that neurons that display high noise correlations in emergent microcircuits feature functional connections which are inevitable for information encoding in the primary visual cortex.
神经相关性（噪声相关性和互相关图）被广泛研究以推断神经元之间的功能连接。据报道，神经元之间的高噪声相关性会提高神经元群体的编码准确性；然而，低噪声相关性在皮质微电路中也被证明起着关键作用。因此，噪声相关性在神经编码中的作用备受争议。为此，我们通过多电极记录了麻醉猫初级视觉皮层中的神经元集群。通过计算互相关图，我们揭示了与特定方向相关的集群内神经元之间的功能网络（微电路）。我们表明，在响应特定方向而激活的微电路中，功能连接的神经元系统地表现出比功能未连接的神经元更高的噪声相关性。此外，随着用于计算噪声相关性的分辨率窗口的变化，连接神经元的噪声相关性平均强度比未连接神经元急剧增加。我们认为，在新兴微电路中表现出高噪声相关性的神经元具有功能连接，这对于初级视觉皮层中的信息编码是必不可少的。
