DeLorenzo Robert J, Sun David A, Deshpande Laxmikant S
Department of Neurology, Virginia Commonwealth University, School of Medicine, Richmond, 23298-0599, USA.
Pharmacol Ther. 2006 Jul;111(1):288-325. doi: 10.1016/j.pharmthera.2004.10.015.
Epilepsy is one of the most common neurological disorders. Although epilepsy can be idiopathic, it is estimated that up to 50% of all epilepsy cases are initiated by neurological insults and are called acquired epilepsy (AE). AE develops in 3 phases: (1) the injury [central nervous system (CNS) insult]. (2) epileptogenesis (latency), and (3) the chronic epileptic (spontaneous recurrent seizure) phases. Status epilepticus (SE), stroke, and traumatic brain injury (TBI) are 3 major examples of common brain injuries that can lead to the development of AE. It is especially important to understand the molecular mechanisms that cause AE because it may lead to innovative strategies to prevent or cure this common condition. Recent studies have offered new insights into the cause of AE and indicate that injury-induced alterations in intracellular calcium concentration levels (Ca(2+)) and calcium homeostatic mechanisms play a role in the development and maintenance of AE. The injuries that cause AE are different, but the share a common molecular mechanism for producing brain damage--an increase in extracellular glutamate and are exposed to increased Ca(2+) are the cellular substrates to develop epilepsy because dead cells do not seize. The neurons that survive injury sustain permanent long-term plasticity changes in Ca(2+) and calcium homeostatic mechanisms that are permanent and are a prominent feature of the epileptic phenotype. In the last several years, evidence has accumulated indicating that the prolonged alteration in neuronal calcium dynamics plays an important role in the induction and maintenance of the prolonged neuroplasticity changes underlying the epileptic phenotype. Understanding the role of calcium as a second messenger in the induction and maintenance of epilepsy may provide novel insights into therapeutic advances that will prevent and even cure AE.
癫痫是最常见的神经系统疾病之一。尽管癫痫可能是特发性的,但据估计,所有癫痫病例中高达50%是由神经损伤引发的,被称为获得性癫痫(AE)。AE的发展分为三个阶段:(1)损伤[中枢神经系统(CNS)损伤];(2)癫痫发生(潜伏期);(3)慢性癫痫(自发性反复癫痫发作)阶段。癫痫持续状态(SE)、中风和创伤性脑损伤(TBI)是可导致AE发生的常见脑损伤的三个主要例子。了解导致AE的分子机制尤为重要,因为这可能会带来预防或治愈这种常见病症的创新策略。最近的研究为AE的病因提供了新的见解,并表明损伤诱导的细胞内钙浓度水平(Ca(2+))变化和钙稳态机制在AE的发展和维持中起作用。导致AE的损伤各不相同,但它们有一个共同的造成脑损伤的分子机制——细胞外谷氨酸增加,而暴露于升高的Ca(2+)是发生癫痫的细胞底物,因为死细胞不会发作。在损伤中存活下来的神经元在Ca(2+)和钙稳态机制方面维持着永久性的长期可塑性变化,这些变化是永久性的,并且是癫痫表型的一个显著特征。在过去几年中,越来越多的证据表明,神经元钙动力学的长期改变在癫痫表型所基于的长期神经可塑性变化的诱导和维持中起重要作用。了解钙作为第二信使在癫痫诱导和维持中的作用,可能会为预防甚至治愈AE的治疗进展提供新的见解。