Dalla Porta Leonardo, Matias Fernanda S, Dos Santos Alfredo J, Alonso Ana, Carelli Pedro V, Copelli Mauro, Mirasso Claudio R
System Neuroscience Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
Instituto de Física, Universidade Federal de Alagoas, Maceió, Brazil.
Front Syst Neurosci. 2019 Aug 21;13:41. doi: 10.3389/fnsys.2019.00041. eCollection 2019.
Synchronization is one of the brain mechanisms allowing the coordination of neuronal activity required in many cognitive tasks. Anticipated Synchronization (AS) is a specific type of out-of-phase synchronization that occurs when two systems are unidirectionally coupled and, consequently, the information is transmitted from the sender to the receiver, but the receiver leads the sender in time. It has been shown that the primate cortex could operate in a regime of AS as part of normal neurocognitive function. However it is still unclear what is the mechanism that gives rise to anticipated synchronization in neuronal motifs. Here, we investigate the synchronization properties of cortical motifs on multiple scales and show that the internal dynamics of the receiver, which is related to its free running frequency in the uncoupled situation, is the main ingredient for AS to occur. For biologically plausible parameters, including excitation/inhibition balance, we found that the phase difference between the sender and the receiver decreases when the free running frequency of the receiver increases. As a consequence, the system switches from the usual delayed synchronization (DS) regime to an AS regime. We show that at three different scales, neuronal microcircuits, spiking neuronal populations and neural mass models, both the inhibitory loop and the external current acting on the receiver mediate the DS-AS transition for the sender-receiver configuration by changing the free running frequency of the receiver. Therefore, we propose that a faster internal dynamics of the receiver system is the main mechanism underlying anticipated synchronization in brain circuits.
同步是一种大脑机制，可使许多认知任务所需的神经元活动实现协调。预期同步（AS）是一种特定类型的异相同步，当两个系统单向耦合时就会出现，因此信息从发送者传输到接收者，但接收者在时间上领先于发送者。研究表明，灵长类动物的皮层可以作为正常神经认知功能的一部分，在预期同步状态下运行。然而，目前仍不清楚在神经元基序中产生预期同步的机制是什么。在这里，我们研究了多个尺度上皮层基序的同步特性，并表明接收者的内部动力学，这与其在未耦合状态下的自由振荡频率有关，是预期同步发生的主要因素。对于包括兴奋/抑制平衡在内的生物学上合理的参数，我们发现当接收者的自由振荡频率增加时，发送者和接收者之间的相位差会减小。因此，系统从通常的延迟同步（DS）状态切换到预期同步状态。我们表明，在神经元微电路、发放神经元群体和神经质量模型这三个不同尺度上，作用于接收者的抑制回路和外部电流都通过改变接收者的自由振荡频率，介导了发送者 - 接收者配置的DS - AS转变。因此，我们提出，接收者系统更快的内部动力学是大脑回路中预期同步的主要潜在机制。
