Department of Translational Neuroscience, Cajal Institute, CSIC, Av. Doctor Arce 37, Madrid 28002, Spain.
Department of Applied Mathematics, Institute for Interdisciplinary Mathematics, Universidad Complutense of Madrid, Av. Paraninfo s/n, Madrid 28040, Spain.
Cereb Cortex. 2023 Mar 21;33(7):3636-3650. doi: 10.1093/cercor/bhac297.
The activity of neuron populations gives rise to field potentials (FPs) that extend beyond the sources. Their mixing in the volume dilutes the original temporal motifs in a site-dependent manner, a fact that has received little attention. And yet, it potentially rids of physiological significance the time-frequency parameters of individual waves (amplitude, phase, duration). This is most likely to happen when a single source or a local origin is erroneously assumed. Recent studies using spatial treatment of these signals and anatomically realistic modeling of neuron aggregates provide convincing evidence for the multisource origin and site-dependent blend of FPs. Thus, FPs generated in primary structures like the neocortex and hippocampus reach far and cross-contaminate each other but also, they add and even impose their temporal traits on distant regions. Furthermore, both structures house neurons that act as spatially distinct (but overlapped) FP sources whose activation is state, region, and time dependent, making the composition of so-called local FPs highly volatile and strongly site dependent. Since the spatial reach cannot be predicted without source geometry, it is important to assess whether waveforms and temporal motifs arise from a single source; otherwise, those from each of the co-active sources should be sought.
神经元群体的活动产生了在源之外延伸的场电位 (FPs)。它们在体积中的混合以依赖于位置的方式稀释了原始的时间图案，这一事实很少受到关注。然而，它可能会消除个体波的时间-频率参数的生理意义（幅度、相位、持续时间）。当错误地假设单个源或局部起源时，最有可能发生这种情况。最近使用这些信号的空间处理和神经元群体的解剖现实建模的研究为 FPs 的多源起源和位置依赖混合提供了令人信服的证据。因此，在新皮层和海马体等主要结构中产生的 FPs 传播很远，相互交叉污染，但它们也会添加甚至将其时间特征强加给遥远的区域。此外，这两个结构都包含作为空间上不同（但重叠）FP 源的神经元，其激活状态、区域和时间依赖性，使得所谓的局部 FPs 的组成高度不稳定且强烈依赖于位置。由于没有源几何形状就无法预测空间范围，因此评估波形和时间图案是否来自单个源很重要；否则，应该寻找来自每个共同激活源的那些。
