Cha Seongkwang, Ahn Jungryul, Jeong Yurim, Lee Yong Hee, Kim Hyong Kyu, Lee Daekee, Yoo Yongseok, Goo Yong Sook
Department of Physiology, Chungbuk National University School of Medicine, Cheongju, South Korea.
Department of Biochemistry, Chungbuk National University School of Medicine, Cheongju, South Korea.
Front Cell Neurosci. 2022 Jul 19;16:926096. doi: 10.3389/fncel.2022.926096. eCollection 2022.
One of the critical prerequisites for the successful development of retinal prostheses is understanding the physiological features of retinal ganglion cells (RGCs) in the different stages of retinal degeneration (RD). This study used our custom-made mice, C57BL/6- /Korl mutated on the Pde6b gene in C57BL/6J mouse with the CRISPR/Cas9-based gene-editing method. We selected the postnatal day (P) 45, P70, P140, and P238 as representative ages for RD stages. The optomotor response measured the visual acuity across degeneration stages. At P45, the mice exhibited lower visual acuity than wild-type (WT) mice. At P140 and older, no optomotor response was observed. We classified RGC responses to the flashed light into ON, OFF, and ON/OFF RGCs multichannel recording. With degeneration, the number of RGCs responding to the light stimulation decreased in all three types of RGCs. The OFF response disappeared faster than the ON response with older postnatal ages. We elicited RGC spikes with electrical stimulation and analyzed the network-mediated RGC response in the mice. Across all postnatal ages, the spikes of RGCs were less elicited by pulse amplitude modulation than in WT RGCs. The ratio of RGCs showing multiple peaks of spike burst increased in older ages. The electrically evoked RGC spikes by the pulse amplitude modulation differ across postnatal ages. Therefore, degeneration stage-dependent stimulation strategies should be considered for developing retinal prosthesis and successful vision restoration.
视网膜假体成功开发的关键前提之一是了解视网膜变性（RD）不同阶段视网膜神经节细胞（RGC）的生理特征。本研究使用我们定制的小鼠，通过基于CRISPR/Cas9的基因编辑方法，在C57BL/6J小鼠的Pde6b基因上进行突变得到C57BL/6 - /Korl小鼠。我们选择出生后第（P）45天、P70天、P140天和P238天作为RD阶段的代表性年龄。视动反应测量了整个变性阶段的视力。在P45时，这些小鼠的视力低于野生型（WT）小鼠。在P140及更大年龄时，未观察到视动反应。我们通过多通道记录将RGC对闪光的反应分为ON、OFF和ON/OFF RGC。随着变性，在所有三种类型的RGC中，对光刺激有反应的RGC数量减少。随着出生后年龄的增加，OFF反应比ON反应消失得更快。我们通过电刺激诱发RGC尖峰，并分析了这些小鼠中网络介导的RGC反应。在所有出生后年龄中，与WT RGC相比，脉冲幅度调制诱发的这些RGC尖峰较少。显示尖峰爆发多个峰值的RGC比例在较大年龄时增加。脉冲幅度调制诱发的电诱发RGC尖峰在出生后各年龄有所不同。因此，在开发视网膜假体和成功恢复视力时，应考虑依赖变性阶段的刺激策略。
