Cortical tuber and epilepsy

 描述（由申请人提供）：多发性硬化症（TSC）是一种常染色体显性遗传疾病，发生于1/6，000的个体中，TSC 1或TSC 2突变导致mTOR活性增加。大约80- 90%的TSC患者会经历不同类型的癫痫发作。大多数类型的癫痫发作是难治性的治疗，需要侵入性手术切除，导致只有50%的情况下可管理的癫痫发作。因此，迫切需要改善TSC中的癫痫治疗。为了开发这种治疗方法，我们需要更好地了解癫痫发作的机制。众所周知，局灶性皮质畸形（TSC中称为皮质结节）与癫痫相关，但由于缺乏局灶性皮质畸形相关癫痫的实验模型，因此了解结节如何产生癫痫发作是有限的。在这里，我们已经产生了一个新的模型，局灶性结节相关的癫痫发作，我们建议进一步表征它，并解决一些可能的癫痫发生/癫痫发作的机制。在人类中，我们发现，实验皮质块茎的特点是皮质层的损失，存在异位，细胞肥大的神经元与肥大的树突，和胶质细胞增生。我们的总体假设是，阻止其中一种改变可能足以阻止癫痫发作。在这里，由于R21的探索性质和短持续时间，我们专注于两个特定的改变，与电路紊乱相关的神经元错位，以及mTORC 1诱导的生物物理特性变化（即，起搏器通道异常采集）。我们更具体的假设是，防止神经元错位或生物物理特性的特定改变可以防止癫痫发作。为了解决这个假设，我们有两个目标，一个集中在神经元错位和其他一个生物物理特性的块茎神经元。我们将使用多种方法的组合，包括子宫内电穿孔以增加发育中的皮层神经元中的mTOR活性，然后通过切片中的膜片钳记录和脑电图（EEG）/行为记录来监测体内癫痫样放电。此外，我们将使用条件方法以及工程受体来沉默体内神经元。这种方法的结合是创新的，我们处于完成拟议工作的独特地位。最后，TSC是mTOR依赖性局灶性皮质畸形相关癫痫的示例性病症。另一种疾病是局灶性皮质发育不良（FCD）II型，其具有相似的分子和细胞改变。因此，我们的模型适用于FCD II型。这两种疾病都是局灶性畸形相关的难治性癫痫的主要原因。

 DESCRIPTION (provided by applicant): Tuberous sclerosis complex (TSC) is an autosomal dominant disorder occurring in 1/6,000 individuals with mutations in TSC1 or TSC2 leading to increased mTOR activity. About 80- 90% of the TSC individuals will experience seizures of different types. Most types of seizures are refractory to treatment and require invasive surgical resection leading to manageable seizures in only 50% of the cases. There is thus a serious need to improve epilepsy treatment in TSC. To develop such treatment, we need to better understand the mechanisms of seizure generation. It is known that focal cortical malformations, called cortical tubers in TSC are associated with epilepsy, but understanding how tubers generate seizures is limited because of the lack of an experimental model of focal cortical malformation-associated epilepsy. Here, we have generated a novel model of focal tuber-associated seizures, and we propose to further characterize it and address some of the possible mechanisms of epileptogenesis/seizures. As in humans, we found that experimental cortical tubers are characterized by loss of cortical lamination, the presence of ectopic, cytomegalic neurons with hypertrophic dendrites, and gliosis. Our overarching hypothesis is preventing one of the alterations may be sufficient to prevent seizure generation. Here, due to the exploratory nature and the short duration of a R21, we focused on two specific alterations, neuronal misplacement which is associated with circuit disorganization, and mTORC1-induced changes in biophysical properties (i.e., abnormal acquisition of pacemaker channel). Our more specific hypothesis is that preventing neuronal misplacement or specific alterations in biophysical properties prevents seizures. To address this hypothesis, we have two aims, one focused on neuronal misplacement and the other one on the biophysical properties of tuber neurons. We will use a combination of approaches including in utero electroporation to increase mTOR activity in developing cortical neurons followed by patch clamp recordings in slices and electroencephalogram (EEG)/behavior recordings to monitor epileptiform discharges in vivo. In addition, we will use conditional approaches as well as engineered receptors to silence neurons in vivo. This combination of approaches is innovative and we are in a unique position to accomplish the proposed work. Finally, TSC is an exemplary disorder of mTOR-dependent focal cortical malformation-associated epilepsy. The other disorder is focal cortical dysplasia (FCD) type II, which share similar molecular and cellular alterations. Our model is thus applicable to FCD type II. Both disorders are the leading cause of focal malformation-associated refractory epilepsy.s