Chen He, Wang Menghan, Xia Lin, Dong Jiong, Xu Guangwei, Wang Ziyi, Feng Lixia, Zhou Yifeng
Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China.
School of Information Science and Technology, University of Science and Technology of China, Hefei, China.
Diabetes. 2022 Aug 1;71(8):1772-1784. doi: 10.2337/db21-0715.
Diabetes can damage both the peripheral sensory organs, causing retinopathy, and the central visual system, leading to contrast sensitivity and impaired color vision in patients without retinopathy. Orientation discrimination is important for shape recognition by the visual system. Our psychophysical findings in this study show diminished orientation discrimination in patients with diabetes without retinopathy. To reveal the underlying mechanism, we established a diabetic mouse model and recorded in vivo electrophysiological data in the dorsal lateral geniculate nucleus (dLGN) and primary visual cortex (V1). Reduced orientation selectivity was observed in both individual and populations of neurons in V1 and dLGN, which increased in severity with disease duration. This diabetes-associated neuronal dysfunction appeared earlier in the V1 than dLGN. Additionally, neuronal activity and signal-to-noise ratio are reduced in V1 neurons of diabetic mice, leading to a decreased capacity for information processing by V1 neurons. Notably, the V1 in diabetic mice exhibits reduced excitatory neuronal activity and lower levels of phosphorylated mammalian target of rapamycin (mTOR). Our findings show that altered responses of both populations of and single V1 neurons may impair fine vision, thus expanding our understanding of the underlying causes of diabetes-related impairment of the central nervous system.
糖尿病既能损害周围感觉器官，引发视网膜病变，也能损害中枢视觉系统，导致无视网膜病变患者的对比敏感度下降和色觉受损。方向辨别对于视觉系统识别形状很重要。我们在本研究中的心理物理学结果表明，无视网膜病变的糖尿病患者的方向辨别能力下降。为了揭示其潜在机制，我们建立了糖尿病小鼠模型，并记录了背侧外侧膝状体核（dLGN）和初级视觉皮层（V1）的体内电生理数据。在V1和dLGN的单个神经元和神经元群体中均观察到方向选择性降低，且其严重程度随病程增加。这种与糖尿病相关的神经元功能障碍在V1中比在dLGN中出现得更早。此外，糖尿病小鼠V1神经元的神经元活动和信噪比降低，导致V1神经元的信息处理能力下降。值得注意的是，糖尿病小鼠的V1表现出兴奋性神经元活动减少和磷酸化雷帕霉素哺乳动物靶标（mTOR）水平降低。我们的研究结果表明，V1神经元群体和单个V1神经元的反应改变可能会损害精细视觉，从而扩展了我们对糖尿病相关中枢神经系统损伤潜在原因的理解。
