Effects of pregabalin and thrombospondins on enhanced excitatory connectivity, new synapse formation and epileptogenesis after neocortical injury

描述(申请人提供)：加巴喷丁和血栓反应蛋白对新皮质损伤后增强的兴奋性连接、新的突触形成和癫痫发生的影响大脑皮层和海马神经元之间新的兴奋性连接的萌发、神经胶质细胞的变化和兴奋性突触的形成是脑损伤的后果，被认为是导致动物模型和人脑癫痫的原因。目前还没有有效的预防性治疗来防止脑损伤后癫痫的发生。计划中的实验将重点放在一种新的方法上，以限制皮质损伤后兴奋性连接增加和癫痫的发展。星形胶质细胞分泌的血栓反应蛋白(TSP)参与发育过程中和皮质损伤后新的兴奋性突触的形成。实验将验证这样的假设，即普瑞巴林(PGB)(Lyrica)是一种被批准的药物，它干扰TSP与其Alpha2Delta-1受体的结合，将减少兴奋性突触的形成和萌发，并限制癫痫样活动的发展。PGB和TSP的作用将在NA�Ve小鼠致痫新皮质损伤的部分皮质隔离(“UnderCut”，UC)模型、TSP“基因敲除”小鼠和高表达α2Delta-1的癫痫小鼠中进行探讨。体外皮层记录的癫痫样活动的发生率 损伤后的脑片、轴突发芽、兴奋性突触密度和网络连接将使用电生理和解剖学技术进行测量。笼养谷氨酸的激光扫描光刺激将与全细胞记录相结合，以绘制大脑皮层切片中的兴奋性连接。在NA�Ve或损伤的皮质中，将研究神经元过度活动与TSP、α2β-1受体和新突触形成之间的可能联系。将评估体内皮质损伤后PGB治疗对这些措施的影响，以检验该药物将减少脑损伤后的结构和功能异常并导致癫痫发展的假设。。相关：创伤后癫痫是严重的新皮质或海马区损伤的显著后果，它改变了神经元和神经胶质的结构和功能，并导致皮质回路的过度兴奋。不幸的是，一旦癫痫发作发生，治疗往往无效，而且没有任何药物可以阻止导致创伤后癫痫的致痫过程。这些实验结果将有助于理解皮质损伤的细胞和电路效应，并为加巴喷丁和普瑞巴林预防脑损伤后癫痫的发展提供新的信息。

DESCRIPTION (provided by applicant): The effects of gabapentin and thrombospondins on enhanced excitatory connectivity, new synapse formation and epileptogenesis after neocortical injury sprouting of new excitatory wiring between neurons in cerebral cortex and hippocampus, changes in glial cells and formation of excitatory synapses are consequences of brain injury that are thought to contribute to epilepsy in animal models and human brain. There is no effective prophylactic treatment available to prevent epileptogenesis after brain injury. The planned experiments focus on a new approach for limiting the development of the increased excitatory connections and epilepsy after cortical trauma. Astrocyte-secreted thrombospondins (TSPs) are involved in new excitatory synapse formation during development and after cortical injury. Experiments will test the hypothesis that pregabalin (PGB) (Lyrica), an approved drug that interferes with the binding of TSPs to their alpha2delta-1 receptor, will decrease excitatory synapse formation and sprouting and limit development of epileptiform activity. The effects of PGB and TSPs will be explored in the partial cortical isolation ("undercut", UC) model of epileptogenic neocortical injury in na�ve mice, in TSP "knockout" mice and alpha2delta-1 overexpressing epileptic mice. The incidence of epileptiform activity recorded in in vitro cortical slices after injury, sprouting of axons, density of excitatory synapses and network connectivity will be measured using electrophysiological and anatomical techniques. Laser scanning photostimulation of caged glutamate will be used in conjunction with whole cell recordings to map excitatory connections in cortical slices. A possible link between excessive neuronal activity and increases in TSPs, the alpha2delta-1 receptor and new synapse formation will be studied in na�ve or injured cortex. The effects of PGB treatment after cortical injury in vivo on these measures will be assessed to test the hypothesis that the drug will decrease the structural and functional abnormalities that follow brain trauma and lead to the development of epilepsy. . Relevance: Posttraumatic epilepsy is a prominent consequence of serious neocortical or hippocampal injury that alters neuronal and glial structure and function and induces hyperexcitability in cortical circuits. Unfortunately, treatment is often ineffective at relieving seizures once they occur and no drug is available that will prevent the epileptogenic processes that lead to posttraumatic epilepsy. Results of these experiments will contribute to understanding cellular and circuit effects of cortical injury, and provide new information about a potential role for gabapentin and pregabalin to prevent development of epilepsy after brain injury.