Lee Jae-Ik, Hadjinicolaou Alex E, Fried Shelley I
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:3533-3536. doi: 10.1109/EMBC44109.2020.9175373.
Microelectronic retinal prostheses electrically stimulate retinal neurons with the goal of restoring vision in patients blinded by outer retinal degeneration. Despite some success in clinical trials, the quality of vision elicited by these devices is still limited. To improve the performance of retinal prostheses, our group studied how retinal neurons respond to electric stimulation. Our previous work showed that responses of retinal ganglion cells (RGCs) are frequency-dependent and different types of RGCs can be preferentially activated with a specific frequency and current amplitude. In the present study, we systemically examined responses of RGCs to sinusoidal electric stimulation with varying frequencies and amplitudes. We found that ON sustained alpha RGCs show distinct stimulus-response relationships to low and high frequency stimulation. For example, RGCs showed monotonic response curves to 500 Hz sinusoidal stimulation, whereas they showed non-monotonic response curves to 2000 Hz stimulation. We also described how increasing stimulus frequency gradually changed the response curves of RGCs.
微电子视网膜假体通过电刺激视网膜神经元，旨在恢复因外层视网膜变性而失明患者的视力。尽管临床试验取得了一些成功，但这些设备所引发的视觉质量仍然有限。为了提高视网膜假体的性能，我们团队研究了视网膜神经元对电刺激的反应。我们之前的工作表明，视网膜神经节细胞（RGCs）的反应是频率依赖性的，不同类型的RGCs可以通过特定的频率和电流幅度被优先激活。在本研究中，我们系统地研究了RGCs对不同频率和幅度的正弦电刺激的反应。我们发现，ON持续α RGCs对低频和高频刺激表现出不同的刺激-反应关系。例如，RGCs对500Hz正弦刺激表现出单调反应曲线，而对2000Hz刺激表现出非单调反应曲线。我们还描述了刺激频率的增加如何逐渐改变RGCs的反应曲线。
