Gene-based Neuromodulation: A New Paradigm for Functional Neurosurgery

描述（由申请人提供）：目前的提案将继续Boulis博士作为功能神经外科领域的临床医生和科学家的职业发展，专注于现有神经调节策略的替代方案。神经调节是解剖学上离散目标内神经活动的操纵，是功能神经外科的主要工具，在运动障碍、疼痛、痉挛、癫痫和精神疾病的治疗中得到应用。它已经在很大程度上取代了神经组织的破坏，成为治疗难治性功能障碍的一种手段。然而，电流的集中传递不具备药理学特异性，需要电子神经假体，这有很大的并发症率。在治疗功能性神经疾病方面，病毒基因疗法比植入装置有几个优点。神经元基因表达可以通过微创立体定向注射实现。此外，可以通过操纵病毒表面来设计病毒载体的趋向性，使其靶向单个细胞类型，并限制和指导基因表达的传播。最后，病毒基因表达可以在不破坏神经元结构或突触结构的情况下以持续的方式实现。因此，基因转移可用于以当前外科手术无法实现的方式操纵功能神经结构，提供药理学和解剖学特异性的双重优势。下面的提案探讨了载体的发展，以实现控制突触功能的调节，利用现有的最佳诱导基因表达系统，以调节释放破伤风梭菌毒素光（LC）基因和内校正钾通道（Kir2.1）基因。本研究的目的是验证以下假设：1)AAV介导的LC突触抑制比腺病毒介导的传递更持久，免疫原性更低，并且持久的表达可以由Tet-on系统调节。2)表达盒修饰，将表达靶向运动神经元，并将转基因传递到轴突，可以提高LC基因神经抑制的效力和特异性。3) Rheoswitch(r)诱导表达系统将改善可控LC传递。4)神经元Kir2.1基因表达可安全抑制神经元活性，其抑制效力超过LC介导的突触抑制。

DESCRIPTION (provided by applicant): The present proposal will continue the career development of Dr. Boulis as a clinician-scientist in the field of Functional Neurosurgery, focusing on an alternative to existing strategies for Neuromodulation. Neuromodulation, the manipulation of neural activity within anatomically discrete targets, is the principle tool of Functional Neurosurgery, finding application in the treatment of movement disorders, pain, spasticity, epilepsy and psychiatric disease. It has largely replaced the destruction of neural tissue as a means to treat refractory functional disorders. Nonetheless, the focused delivery of electric current is incapable of pharmacological specificity and requires electronic neural prostheses that carry a significant complication rate. Viral gene therapy has several advantages over implanted devices for the treatment of functional neural disorders. Neuronal gene expression can be achieved through minimally invasive stereotactic injection. Moreover, the tropism of viral vectors can be engineered through manipulation of the virus surface to target the vectors to individual cell types as well as limit and direct the spread of gene expression. Finally, viral gene expression can be achieved in a sustained fashion in neurons without disrupting their architecture or synaptic structure. Thus, gene transfer can be used to manipulate functioning neural structures in a fashion that current surgical procedures cannot achieve, providing the dual advantage of both pharmacologic and anatomic specificities. The following proposal explores the development of vectors to achieve controlled modulation of synaptic function using the best available inducible gene expression systems for regulated release of the clostridial tetanus toxin light (LC) gene and the inwardly rectifying potassium channel (Kir2.1) gene. Aims of the current proposal will test the following hypotheses: 1) AAV mediated LC synaptic inhibition is durable and less immunogenic than delivery mediated by Adenovirus, and that durable expression can be regulated by the Tet-on system. 2) Expression cassette modification, targeting expression to motor neurons and transgene delivery to axons, can improve the potency and specificity of LC gene-based neural inhibition. 3) The Rheoswitch(r) inducible expression system will improve controlled LC delivery. 4) Neuronal Kir2.1 gene expression can safely inhibit neuronal activity with potency exceeding that of LC mediated synaptic inhibition.