Institute for Advanced Simulation (IAS-6), Jülich Research Centre, Wilhelm-Johnen-Str., 52428 Jülich, Germany.
Sussex AI, School of Engineering and Informatics, University of Sussex, Chichester, Falmer, Brighton BN1 9QJ, United Kingdom.
Cereb Cortex. 2024 Oct 3;34(10). doi: 10.1093/cercor/bhae405.
Multi-electrode arrays covering several square millimeters of neural tissue provide simultaneous access to population signals such as extracellular potentials and spiking activity of one hundred or more individual neurons. The interpretation of the recorded data calls for multiscale computational models with corresponding spatial dimensions and signal predictions. Multi-layer spiking neuron network models of local cortical circuits covering about $1,{\text{mm}^{2}}$ have been developed, integrating experimentally obtained neuron-type-specific connectivity data and reproducing features of observed in-vivo spiking statistics. Local field potentials can be computed from the simulated spiking activity. We here extend a local network and local field potential model to an area of $4\times 4,{\text{mm}^{2}}$, preserving the neuron density and introducing distance-dependent connection probabilities and conduction delays. We find that the upscaling procedure preserves the overall spiking statistics of the original model and reproduces asynchronous irregular spiking across populations and weak pairwise spike-train correlations in agreement with experimental recordings from sensory cortex. Also compatible with experimental observations, the correlation of local field potential signals is strong and decays over a distance of several hundred micrometers. Enhanced spatial coherence in the low-gamma band around $50,\text{Hz}$ may explain the recent report of an apparent band-pass filter effect in the spatial reach of the local field potential.
多电极阵列覆盖几平方毫米的神经组织，可同时获取群体信号，如 100 个或更多单个神经元的细胞外电势和尖峰活动。记录数据的解释需要具有相应空间维度和信号预测的多尺度计算模型。已经开发出了覆盖约 $1,{\text{mm}^{2}}$ 的局部皮质电路的多层尖峰神经元网络模型，整合了实验获得的神经元类型特异性连接数据，并再现了体内观察到的尖峰统计特征。可以从模拟的尖峰活动中计算局部场电位。我们在这里将局部网络和局部场电位模型扩展到 $4\times 4,{\text{mm}^{2}}$ 的区域，保持神经元密度，并引入距离相关的连接概率和传导延迟。我们发现，扩展过程保留了原始模型的整体尖峰统计特性，并再现了群体间异步不规则尖峰和弱成对尖峰序列相关性，与感觉皮层的实验记录一致。与实验观察结果一致的是，局部场电位信号的相关性很强，并在几百微米的距离上衰减。在约 $50,\text{Hz}$ 的低伽马频段的空间相干性增强，可能解释了局部场电位空间范围中明显的带通滤波器效应的最近报道。
