Medeiros Daniel de Castro, Cota Vinícius Rosa, Oliveira Antonio Carlos P, Moreira Fabricio A, Moraes Márcio Flávio Dutra
Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Laboratório Interdisciplinar de Neuroengenharia e Neurociências, Departamento de Engenharia Elétrica, Universidade Federal de São João Del-Rei, São João Del-Rei, Brazil.
Front Behav Neurosci. 2020 Nov 13;14:603245. doi: 10.3389/fnbeh.2020.603245. eCollection 2020.
The understanding that hyper-excitability and hyper-synchronism in epilepsy are indissociably bound by a cause-consequence relation has only recently been challenged. Thus, therapeutic strategies for seizure suppression have often aimed at inhibiting excitatory circuits and/or activating inhibitory ones. However, new approaches that aim to desynchronize networks or compromise abnormal coupling between adjacent neural circuitry have been proven effective, even at the cost of enhancing local neuronal activation. Although most of these novel perspectives targeting circuitry desynchronization and network coupling have been implemented by non-pharmacological devices, we argue that there may be endogenous neurochemical systems that act primarily in the desynchronization component of network behavior rather than dampening excitability of individual neurons. This review explores the endocannabinoid system as one such possible pharmacological landmark for mimicking a form of "on-demand" desynchronization analogous to those proposed by deep brain stimulation in the treatment of epilepsy. This essay discusses the evidence supporting the role of the endocannabinoid system in modulating the synchronization and/or coupling of distinct local neural circuitry; which presents obvious implications on the physiological setting of proper sensory-motor integration. Accordingly, the process of ictogenesis involves pathological circuit coupling that could be avoided, or at least have its spread throughout the containment of other areas, if such endogenous mechanisms of control could be activated or potentiated by pharmacological intervention. In addition, we will discuss evidence that supports not only a weaker role played on neuronal excitability but the potential of the endocannabinoid system strengthening its modulatory effect, only when circuitry coupling surpasses a level of activation.
癫痫中的过度兴奋性和过度同步性通过因果关系紧密相连,这种认识直到最近才受到挑战。因此,抑制癫痫发作的治疗策略通常旨在抑制兴奋性回路和/或激活抑制性回路。然而,旨在使网络去同步或破坏相邻神经回路之间异常耦合的新方法已被证明是有效的,即使是以增强局部神经元激活为代价。尽管大多数针对回路去同步和网络耦合的新观点是通过非药物装置实现的,但我们认为可能存在内源性神经化学系统,其主要作用于网络行为的去同步成分,而不是抑制单个神经元的兴奋性。本综述探讨了内源性大麻素系统作为一种可能的药理学标志,用于模拟一种类似于深部脑刺激治疗癫痫时所提出的“按需”去同步形式。本文讨论了支持内源性大麻素系统在调节不同局部神经回路的同步和/或耦合中作用的证据;这对适当的感觉运动整合的生理环境具有明显的意义。因此,如果这种内源性控制机制可以通过药物干预激活或增强,那么癫痫发生过程涉及的病理性回路耦合就可以避免,或者至少可以将其传播限制在其他区域。此外,我们将讨论证据,这些证据不仅支持内源性大麻素系统对神经元兴奋性的作用较弱,而且支持只有当回路耦合超过一定激活水平时,内源性大麻素系统才会增强其调节作用的潜力。