论文标题
评估人癫痫皮质的塞氏塞前单神经元活性
Assessing criticality in pre-seizure single-neuron activity of human epileptic cortex
论文作者
论文摘要
癫痫发作的特征是异常和过度的神经活动,在这些神经活动中,皮质网络动态似乎变得不稳定。但是,在大多数情况下,在无癫痫发作期间,癫痫患者的皮层表现出完全稳定的动力学。这就提出了一个问题,即根据这种稳定的默认状态,如何出现反复不稳定。在这项工作中,我们研究了癫痫发作的两种潜在情况:(i)癫痫皮质区域通常可能更接近不稳定性,这会使癫痫患者通常更容易受到癫痫发作,或者(ii)癫痫皮质区域可能会在癫痫发作之前系统地倾向于系统地漂移不稳定。我们分析了20名癫痫患者的癫痫病(局灶性)和非邻核皮质半球的单单元尖峰记录。我们使用一种新型估计量量化了关键框架中不稳定性的距离,该估计量可以从一组记录的神经元组中进行公正的推理。令人惊讶的是,我们没有发现任何两种情况的证据:焦点区域通常都没有更接近不稳定,也没有癫痫发作之前的癫痫发作。实际上,我们来自塞兹前和无癫痫发作间隔的结果表明,尽管癫痫病,人类皮质在稳定的,略微临界的状态下运作,就像其他健康哺乳动物的皮质一样。
Epileptic seizures are characterized by abnormal and excessive neural activity, where cortical network dynamics seem to become unstable. However, most of the time, during seizure-free periods, cortex of epilepsy patients shows perfectly stable dynamics. This raises the question of how recurring instability can arise in the light of this stable default state. In this work, we examine two potential scenarios of seizure generation: (i) epileptic cortical areas might generally operate closer to instability, which would make epilepsy patients generally more susceptible to seizures, or (ii) epileptic cortical areas might drift systematically towards instability before seizure onset. We analyzed single-unit spike recordings from both the epileptogenic (focal) and the nonfocal cortical hemispheres of 20 epilepsy patients. We quantified the distance to instability in the framework of criticality, using a novel estimator, which enables an unbiased inference from a small set of recorded neurons. Surprisingly, we found no evidence for either scenario: Neither did focal areas generally operate closer to instability, nor were seizures preceded by a drift towards instability. In fact, our results from both pre-seizure and seizure-free intervals suggest that despite epilepsy, human cortex operates in the stable, slightly subcritical regime, just like cortex of other healthy mammalians.