Optogenetic and Chemogenetic Dissection of Cell Transplants

据估计，帕金森氏症(PD)导致100万美国人残疾，其特征是 起源于黑质致密部的多巴胺能神经元的进行性丢失及其 轴突。需要某种形式的左旋多巴(LD)来控制绝大多数患者的帕金森病症状，但其 使用会导致药物引起的运动障碍(DID)、运动和非运动波动，使 仍然是当代帕金森病管理中的一个主要问题。间歇性大剂量LD治疗，损失 持续的多巴胺能刺激(CDS)和多巴胺受体的超敏感性是假设的 作为DID和波动的致病因素。人们也很好地接受了从马达传输的信息 帕金森病患者皮质至基底节及背部异常与电生理异常的矫正 可能对缓解晚期帕金森病患者的症状至关重要。我们的研究表明， 帕金森氏症引起的基底节的电生理变化仍然很大程度上仍然存在 尽管帕金森病患者的行为得到了极好的改善，但全天候LD治疗仍未缓解。在……里面 相比之下，多巴胺能细胞移植到纹状体使基底节神经生理学和 帕金森病患者的行为异常。我们发现移植物和宿主之间的突触连接是 对调解这些影响是至关重要和必要的。这些发现表明，突触前因子，如 黑质纹状体突触的存在，使多巴胺能够集中释放，其重新摄取和调节通过 突触前受体对于减少帕金森病的运动并发症可能都很重要。最近的研究表明 表明多巴胺能细胞移植治疗帕金森病是成功的，而且没有不良反应。 为患者提供长达20年的有效抗帕金森病的益处。这导致了 暂停临床细胞移植治疗帕金森病。然而，细胞移植技术的优化 包括从外部控制移植物的功能及其新形成的突触连接的能力 与宿主的关系是确保此类移植物未来临床移植安全的关键。因此，我们寻求 综合评估基底节电生理“正常化”假说- 皮质回路是减轻或消除DID和PD波动所必需的。使用高度可重复性的大鼠 表现为DID的PD模型以及移植物的波动、光发生和化学发生调节 它们可以被关闭和打开，觉醒的基底节单细胞记录，LFP记录，脑电和活体 微渗析结合高效液相色谱-质谱仪，我们计划研究脑出血患者的生化和电异常。 基底节和皮质与DID和PD的波动相关。基底神经节的多个核团 它已知的联系将被探测。还将进行广泛的组织学研究。这项研究 将为DID、运动和非DID伴发的电生理异常提供机制基础。 帕金森病中的运动波动，有助于发现纠正它们的方法。

Parkinson's disease (PD) causes disability in an estimated 1 million Americans and is characterized by progressive loss of dopaminergic neurons that originate in the substantia nigra pars compacta (SNpc) and their axons. Levodopa (LD) in some form is required to control symptoms of PD in vast majority of patients, but its use causes drug-induced dyskinesias (DID), motor and non motor fluctuations, disabling complications that remains a major problem in contemporary management of PD. Intermittent high dose LD treatments, loss of continuous dopaminergic stimulation (CDS) along with dopamine receptor super sensitivity are hypothesized as causative factors for DID and fluctuations. It is also well accepted that information transfer from the motor cortex to the basal ganglia and back is abnormal in PD and correction of electrophysiological abnormalities may be critical to provide symptomatic relief to patients with advanced PD. Our studies show that the electrophysiological changes that occur in the basal ganglia as result of parkinsonism remain largely unmitigated with round the clock LD treatments despite excellent amelioration of parkinsonian behavior. In contrast, dopaminergic cell transplants into the striatum “normalize” basal ganglia neurophysiology and parkinsonian behavioral abnormalities. We show that synaptic connectivity between the graft and the host is critical and necessary to mediate these effects. These findings suggest that pre-synaptic factors such as the presence of nigrostriatal synapses that enables focused release of dopamine, its reuptake and regulation via pre-synaptic receptors may all be important to minimize the motor complications of PD. Recent studies have shown that dopaminergic cell transplantation for PD can be successful and without deleterious side effects providing >2 decades of effective anti-parkinsonian benefits to patients. This has led to the lifting of the moratorium on clinical cell transplantation for PD. However, optimization of cell transplantation techniques including the ability to externally control the functioning of the grafts and its newly formed synaptic connections with the host is critical to ensure safety of future clinical translation of such grafts. Therefore, we seek to comprehensively evaluate the hypothesis that electrophysiological “normalization” in the basal ganglia – cortical circuit is necessary to mitigate or eliminate DID and fluctuations in PD. Using a highly reproducible rat model of PD that exhibit DID and fluctuations, optogenetic and chemogenetic modulation of grafts such that they can be turned “off” and “on”, awake basal ganglia single cell recordings, LFP recordings, EEG and in vivo microdialysis combined with HPLC-Ms/Ms we plan to study the biochemical and electrical abnormalities in the basal ganglia and the cortex associated with DID and fluctuations in PD. Multiple nuclei in the basal ganglia and its known connections will be probed. Extensive histological studies will also be performed. This research will provide mechanistic basis for the electrophysiological abnormalities that accompany DID, motor and non- motor fluctuations in PD and help discover methods to correct them.