Maldonado P E, Friedman-Hill S, Gray C M
The Center for Neuroscience, University of California, 1544 Newton Ct, Davis, CA 95616, USA.
Cereb Cortex. 2000 Nov;10(11):1117-31. doi: 10.1093/cercor/10.11.1117.
Synchronous neuronal activity with millisecond precision has been postulated to contribute to the process of visual perceptual grouping. We have performed multineuron recordings in striate cortex of two alert macaque monkeys to determine if the occurrence and properties of this form of activity are consistent with the minimal requirements of this theory. We find that neuronal synchronization with millisecond precision is a prevalent and robust feature of stimulus-evoked activity in striate cortex. It occurs among adjacent cells recorded by the same electrode (<120 microm), among cells recorded at separate but nearby sites (300-400 microm) and between cells recorded at locations separated by 3-4 mm. The magnitude and probability of synchronous firing is inversely related to the spatial separation between the cells and it occurs within and between groups of cells that are both tuned and untuned for stimulus orientation and direction. Among those tuned for orientation, cell pairs separated by <400 microm showed no clear dependence of correlated firing on orientation preference. The occurrence of gamma-band (20-70 Hz) oscillations in the cellular firing patterns was a strong predictor of synchronous firing at each of the spatial scales. Nearly 90% of the cell pairs showing significant correlation also showed oscillatory firing in one or both cells of the pair. These results are consistent with some, but not all, of the previous reports of synchronous activity in striate cortex of both cat and primates. The similarities in the properties of synchronous oscillations in the monkey and cat suggest that this form of neuronal activity is a general property of mammalian striate cortex. The relation between correlation and oscillation suggests that neuronal rhythmicity is an important mechanism contributing to synchronization.
毫秒级精度的同步神经元活动被认为有助于视觉感知分组过程。我们在两只警觉的猕猴的纹状皮层中进行了多神经元记录，以确定这种活动形式的发生和特性是否符合该理论的最低要求。我们发现，毫秒级精度的神经元同步是纹状皮层中刺激诱发活动的一个普遍且稳健的特征。它发生在同一电极记录的相邻细胞之间（<120微米）、在分开但相邻位置记录的细胞之间（300 - 400微米）以及在相隔3 - 4毫米的位置记录的细胞之间。同步放电的幅度和概率与细胞之间的空间距离成反比，并且它发生在对刺激方向和取向进行调谐和未调谐的细胞组内和组间。在那些对取向进行调谐的细胞中，相隔<400微米的细胞对显示出相关放电对取向偏好没有明显依赖性。细胞放电模式中γ波段（20 - 70赫兹）振荡的出现是每个空间尺度上同步放电的有力预测指标。近90%显示出显著相关性的细胞对在该对中的一个或两个细胞中也显示出振荡放电。这些结果与之前关于猫和灵长类动物纹状皮层同步活动的部分但并非全部报告一致。猴子和猫中同步振荡特性的相似性表明，这种神经元活动形式是哺乳动物纹状皮层的一个普遍特性。相关性与振荡之间的关系表明，神经元节律性是有助于同步的一个重要机制。
