SGER: Biophotonics: Study of Transcorneal Electrical Stimulation in Subjects with Retinitis Pigmentosa

[09:1745 . 58]眼睛捕捉光线，但大脑才是体验视觉的地方。在视网膜水平上，视网膜假体恢复盲人视力的能力已经得到证实，但在视网膜退行性疾病导致的长时间视觉剥夺后，大脑如何接受新的神经信息尚不清楚。视网膜退行性疾病中发生的神经重塑会影响视网膜假体在视力恢复中的有效性。哺乳动物视网膜变性是由视杆细胞、视锥细胞或视网膜色素上皮的基因缺陷引起的，通常会引起光感受器的丧失；因此，有效地离开了没有感觉输入的神经视网膜。神经视网膜通过重塑来应对这种挑战，首先是神经元结构的细微变化，然后是大规模的重组。这种类型的视网膜重塑可以改变视网膜正常的光传输途径，并导致光和电刺激之间不同神经节细胞群的激活。在这个建议中，PI建议使用经角膜电刺激（TcES），通过通过角膜的电流直接刺激视网膜神经节细胞来探测视网膜和视觉皮层之间的神经连接。通过使用正电子发射断层扫描（PET）和18f -氟脱氧葡萄糖（FDG）来比较视网膜光刺激和电刺激对RP患者的大脑激活，我们将增加我们对视网膜重塑如何在视觉皮层中反映的理解。这项研究可以帮助我们深入了解视网膜退行性过程导致的皮层重组。

0917458TsangThe eye captures light but the brain is where vision is experienced. The capacity of retinal prostheses to restore some vision in blind individuals has been demonstrated at the retinal level, but it is unknown how the brain will be receptive to the new neural message after a prolonged period of visual deprivation resulting from retinal degenerative diseases. Neural remodeling that occurs in retinal degenerative diseases can have an impact on the usefulness of retinal prostheses in visual restoration. Mammalian retinal degenerations, initiated by gene defects in rods, cones or the retinal pigmented epithelium, often trigger loss of the photoreceptors; thus, effectively leaving the neural retina without sensory input. The neural retina responds to this challenge by remodeling, first by subtle changes in neuronal structure and later by large-scale reorganization. This type of retinal remodeling can alter normal light transmission pathway in the retina and result in activation of different ganglion cell groups between light and electrical stimulation.In this proposal, the PI proposes to use transcorneal electrical stimulation (TcES) to probe the neural connection between the retina and the visual cortex via direct stimulation of the retinal ganglion cells from a current passing through the cornea. By using positron emission tomography (PET) and 18F-fluorodeoxyglucose (FDG) to compare brain activation between light stimulation and electrical stimulation of the retina in patients with RP, we will be increase our understanding how retinal remodeling is reflected in the visual cortex. The study can then help us gain insight into cortical reorganization resulting from the retinal degenerative process.