The contribution of plasticity to the recovery of retinal function following gene therapy

项目摘要/摘要 遗传性视网膜变性的基因替代疗法改善了动物模型的视觉功能， 这为治愈人类失明积累了动力。最佳治疗方法是恢复正常的视觉功能， 然而，目前的临床试验面临着与恢复的可变性和持久性相关的挑战，这是由于 缺乏对视网膜回路对治疗的反应和任何潜在的机制的严格了解 完全恢复的障碍。为了恢复视力，了解存活的视网膜神经元是如何修改的是至关重要的 视力恢复治疗中的突触连接以及如何利用视网膜的可塑性来改善 视觉功能。我们的长期目标是阐明使视网膜能够建立 基因治疗后的功能联系。拟议工作的目标是确定潜在的 利用色盲小鼠模型在细胞和电路分辨率下的功能恢复机制， 它恢复了基因治疗后选择性丧失的锥体介导的功能。在目标1中，我们将确定 基因治疗后On和Off通路的空间和时间处理的恢复。我们将衡量 特定神经节细胞类型的时空感受野。在目标2中，我们将确定 突触重构和递质释放锥体双极细胞结构和功能的动态平衡 在基因治疗之后。要实现强大和持久的治疗，需要了解基因治疗是如何 恢复一级和二级突触的重新连接和神经递质释放。成像和 电生理学将使我们能够确定视网膜外部和内部的连接模式，以及视锥细胞和 双极细胞的释放率可能会适应输入的变化，以达到内稳态。这种方法是创新的 为了在视网膜可塑性的背景下恢复视力的新视角，研究基因的影响 在视网膜回路的单细胞水平上的连接模式和功能特性的治疗。结果是 将对(1)揭示视网膜可塑性是否有助于恢复视觉功能具有重要意义，(2) 确定允许剩余视网膜神经元重新建立功能连接的机制 新挽救的视锥细胞，以及(3)提供光感受器后最大化功能所必需的知识 恢复。

PROJECT SUMMARY/ABSTRACT Gene replacement therapy for inherited retinal degenerations has improved visual function in animal models, which has built momentum to curing blindness in humans. Optimal therapy is the return of normal visual function, however, current clinical trials face challenges associated with variability and durability of recovery due to the lack of rigorous mechanistic understanding of the retinal circuit's reaction to the therapies and any potential hinderance to full recovery. To restore vision, it is essential to understand how surviving retinal neurons modify synaptic connections upon vision restoration treatment and how retinal plasticity can be leveraged to improve visual function. Our long-term goal is to elucidate fundamental mechanisms that enable the retina to establish functional connections following gene therapy. The objectives of the proposed work are to determine underlying mechanisms of functional recovery at cellular and circuit resolution using a mouse model of achromatopsia, which restores selective loss of cone-mediated function after gene therapy. In Aim 1, we will determine the recovery of spatial and temporal processing in ON and OFF pathways after gene therapy. We will measure spatio-temporal receptive fields of specific ganglion cell types. In Aim 2, we will determine the contribution of synaptic remodeling and transmitter release homeostasis to the structure and function of cone bipolar cells following gene therapy. Achieving robust and sustained therapies require understanding of how gene therapy restores rewiring and neurotransmitter release from first- and second-order synapses. Imaging and electrophysiology will allow us to determine the wiring patterns of outer and inner retina, and how cones and bipolar cell release rates potentially adapt to changes in inputs to reach homeostasis. The approach is innovative for a new perspective on restoring vision in the context of the retinal plasticity investigating the effects of gene therapy on connectivity patterns and functional properties at the single-cell level of the retinal circuit. The results will be significant for (1) revealing whether retinal plasticity is constructive toward restoring visual function, (2) determining mechanisms that allow the remaining retinal neurons to re-establish functional connections with newly rescued cones, and (3) providing knowledge essential for maximizing function after photoreceptor recovery.