Dehghani Nima, Peyrache Adrien, Telenczuk Bartosz, Le Van Quyen Michel, Halgren Eric, Cash Sydney S, Hatsopoulos Nicholas G, Destexhe Alain
Wyss Institute for Biologically-Inspired Engineering, Harvard University, Boston, MA, USA.
New England Complex Systems Institute, Cambridge, MA, USA.
Sci Rep. 2016 Mar 16;6:23176. doi: 10.1038/srep23176.
Balance of excitation and inhibition is a fundamental feature of in vivo network activity and is important for its computations. However, its presence in the neocortex of higher mammals is not well established. We investigated the dynamics of excitation and inhibition using dense multielectrode recordings in humans and monkeys. We found that in all states of the wake-sleep cycle, excitatory and inhibitory ensembles are well balanced, and co-fluctuate with slight instantaneous deviations from perfect balance, mostly in slow-wave sleep. Remarkably, these correlated fluctuations are seen for many different temporal scales. The similarity of these computational features with a network model of self-generated balanced states suggests that such balanced activity is essentially generated by recurrent activity in the local network and is not due to external inputs. Finally, we find that this balance breaks down during seizures, where the temporal correlation of excitatory and inhibitory populations is disrupted. These results show that balanced activity is a feature of normal brain activity, and break down of the balance could be an important factor to define pathological states.
兴奋与抑制的平衡是体内网络活动的一个基本特征，对其计算功能很重要。然而，它在高等哺乳动物新皮层中的存在尚未得到充分证实。我们使用人类和猴子的密集多电极记录来研究兴奋与抑制的动态变化。我们发现，在清醒 - 睡眠周期的所有状态下，兴奋性和抑制性集合都保持良好平衡，并伴随着与完美平衡的轻微瞬时偏差共同波动，这种情况大多出现在慢波睡眠中。值得注意的是，这些相关波动在许多不同的时间尺度上都能观察到。这些计算特征与自生成平衡状态的网络模型的相似性表明，这种平衡活动本质上是由局部网络中的循环活动产生的，而非外部输入所致。最后，我们发现这种平衡在癫痫发作期间会被打破，此时兴奋性和抑制性群体的时间相关性会受到干扰。这些结果表明，平衡活动是正常脑活动的一个特征，而平衡的打破可能是定义病理状态的一个重要因素。
