The mouse motor cortex exhibits spontaneous activity in the form of temporal sequences of neuronal ensembles in vitro without the need of tissue stimulation. These neuronal ensembles are defined as groups of neurons with a strong correlation between its firing patterns, generating what appears to be a predetermined neural conduction mode that needs study. Each ensemble is commonly accompanied by one or more parvalbumin expressing neurons (PV+) or fast spiking interneurons. Many of these interneurons have functional connections between them, helping to form a circuit configuration similar to a small-world network. However, rich club metrics show that most connected neurons are neurons not expressing parvalbumin, mainly pyramidal neurons (PV−) suggesting feed-forward propagation through pyramidal cells. Ensembles with PV+ neurons are connected to these hubs. When ligand-gated fast GABAergic transmission is blocked, temporal sequences of ensembles collapse into a unique synchronous and recurrent ensemble, showing the need of inhibition for coding cortical spontaneous activity. This new ensemble has a duration and electrophysiological characteristics of brief recurrent interictal epileptiform discharges (IEDs) composed by the coactivity of both PV− and PV+ neurons, demonstrating that GABA transmission impedes its occurrence. Synchronous ensembles are clearly divided into two clusters one of them lasting longer and mainly composed by PV+ neurons. Because an ictal-like event was not recorded after several minutes of IEDs recording, it is inferred that an external stimulus and/or fast GABA transmission are necessary for its appearance, making this preparation ideal to study both the neuronal machinery to encode cortical spontaneous activity and its transformation into brief non-ictal epileptiform discharges.

小鼠运动皮层以神经元集成体的时间序列形式表现出自发活动无需组织刺激。这些神经元集合被定义为在其放电模式之间具有很强相关性的神经元组，从而产生似乎是需要研究的预定神经传导模式。每个集合通常都伴随着一个或多个表达小白蛋白的神经元（PV +）或快速突触的中间神经元。这些中子中的许多在它们之间具有功能连接，有助于形成类似于小型世界网络的电路配置。但是，丰富的俱乐部度量标准表明，大多数连接的神经元是不表达小白蛋白的神经元，主要是锥体神经元（PV-），提示通过锥体细胞进行前馈传播。具有PV +神经元的集合连接到这些集线器。当配体选通的快速GABA能传递被阻断时，合奏的时间序列崩溃成独特的同步和循环合奏，表明需要抑制编码皮层自发活动。这种新的合奏具有短暂的反复发作的发作性发作间期癫痫样放电（IED）的持续时间和电生理特性，这些发作由PV-和PV +神经元两者的相互作用组成，表明GABA传播阻碍了它的发生。同步合奏清楚地分为两个簇，其中一个簇持续时间更长，并且主要由PV +神经元组成。由于在记录IED数分钟后未记录到类似发作的事件，因此可以推断，外部刺激和/或快速GABA传递是其出现所必需的，