本期Nature Communications上发表的一项研究表明，移植了视网膜假体的大鼠对光有视觉反应。当该假体被光刺激时，大鼠会在脑部负责视觉处理的区域诱发反应。
近年来，对有可能恢复盲人视力的光电池视觉假体的研究工作加快了步伐；与此同时，虽然它们已被发现能够刺激视网膜组织，但它们是否能恢复视力却没有被评估过。Yossi Mandel及其同事向视网膜退化的大鼠植入视觉假体，然后记录来自其脑中视皮层的神经反应，将这种反应作为视力恢复程度的一个度量。他们发现，视皮层反应可响应于光刺激被诱发。这里所用的光刺激与早先研究中所用的刺激相似，后者研究的是这些装置刺激视网膜组织的有效性。作者承认，还需要更多研究来确定这些装置在恢复全部视力上到底有多成功，但他们希望，这些研究将使人们对光电池方法用于视网膜假体的可行性更加有信心。
“色素性视网膜炎”和与年龄相关的黄斑部退化是西方两个最大的失明原因。虽然一些治疗方法对某些个体能延缓这些疾病的病情发展，但目前还没有已知的治愈手段。（生物谷Bioon.com）
生物谷推荐英文摘要：
Nature Communications DOI:10.1038/ncomms2980
Cortical responses elicited by photovoltaic subretinal prostheses exhibit similarities to visually evoked potentials
Yossi Mandel, Georges Goetz, Daniel Lavinsky, Philip Huie, Keith Mathieson, Lele Wang, Theodore Kamins, Ludwig Galambos, Richard Manivanh, James Harris & Daniel Palanker
We have previously developed a wireless photovoltaic retinal prosthesis, in which camera-captured images are projected onto the retina using pulsed near-IR light. Each pixel in the subretinal implant directly converts pulsed light into local electric current to stimulate the nearby inner retinal neurons. Here we report that implants having pixel sizes of 280, 140 and 70?μm implanted in the subretinal space in rats with normal and degenerate retina elicit robust cortical responses upon stimulation with pulsed near-IR light. Implant-induced eVEP has shorter latency than visible light-induced VEP, its amplitude increases with peak irradiance and pulse duration, and decreases with frequency in the range of 2–20?Hz, similar to the visible light response. Modular design of the arrays allows scalability to a large number of pixels, and combined with the ease of implantation, offers a promising approach to restoration of sight in patients blinded by retinal degenerative diseases.
