Brain field potentials (FPs) can reach far from their sources, making difficult to know which waves come from where. We show that modern algorithms efficiently segregate the local and remote contributions to cortical FPs by recovering the generator-specific spatial voltage profiles. We investigated experimentally and numerically the local and remote origin of FPs in different cortical areas in anesthetized rats. All cortices examined show significant state, layer, and region dependent contribution of remote activity, while the voltage profiles help identify their subcortical or remote cortical origin. Co-activation of different cortical modules can be discriminated by the distinctive spatial features of the corresponding profiles. All frequency bands contain remote activity, thus influencing the FP time course, in cases drastically. The reach of different FP patterns is boosted by spatial coherence and curved geometry of the sources. For instance, slow cortical oscillations reached the entire brain, while hippocampal theta reached only some portions of the cortex. In anterior cortices, most alpha oscillations have a remote origin, while in the visual cortex the remote theta and gamma even surpass the local contribution. The quantitative approach to local and distant FP contributions helps to refine functional connectivity among cortical regions, and their relation to behavior.

中文翻译：

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皮质场电位的局部和体积传导贡献。

脑电势（FPs）可能无法到达其源头，因此很难知道哪些波从何而来。我们表明，现代算法通过恢复特定于发生器的空间电压分布图，有效地隔离了对皮质FP的本地和远程贡献。我们通过实验和数值研究了麻醉大鼠不同皮质区域中FPs的局部和远距离起源。所有检查的皮质均显示出远处活动的重要状态，层和区域依赖性，而电压分布有助于确定其皮层下或远处的皮质起源。不同皮质模块的共同激活可以通过相应轮廓的独特空间特征来区分。所有频段都包含远程活动，因此在严重的情况下会影响FP时程。源的空间连贯性和弯曲的几何形状提高了不同FP模式的覆盖范围。例如，缓慢的皮层振荡到达整个大脑，而海马体仅到达皮层的某些部分。在前皮质中，大多数α振荡起源很远，而在视觉皮层中，远侧θ和γ甚至超过了局部贡献。局部和远方FP贡献的定量方法有助于改善皮质区域之间的功能连通性，以及它们与行为的关系。而在视觉皮层中，远处的θ和γ甚至超过了局部贡献。局部和远方FP贡献的定量方法有助于改善皮质区域之间的功能连通性，以及它们与行为的关系。而在视觉皮层中，远处的θ和γ甚至超过了局部贡献。局部和远方FP贡献的定量方法有助于改善皮质区域之间的功能连通性，以及它们与行为的关系。