Department of Child Healthcare, Women's Hospital of Nanjing Medical University, Nanjing Women and Children's Healthcare Hospital, 123 Tianfei Street, Nanjing, 210004, China.
Department of Pediatrics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, 71 Hexi Street, Nanjing, 210019, China.
BMC Ophthalmol. 2024 Oct 31;24(1):475. doi: 10.1186/s12886-024-03742-w.
The development of the zebrafish visual system is significantly influenced by exposure to monochromatic light, yet investigations into its effects during juvenile stages are lacking. This study evaluated the impacts of varying intensities and durations of red and blue monochromatic light on the visual system and dopamine pathways in juvenile zebrafish.
Juvenile zebrafish were exposed to red (650 nm) and blue (440 nm, 460 nm) monochromatic lights over four days at intensities ranging from 500 to 10,000 lx, for durations of 6, 10, and 14 h daily. A control group was maintained under standard laboratory conditions. Post-exposure assessments included the optokinetic response (OKR), retinal structural analysis, ocular dopamine levels, and the expression of genes related to dopamine pathways (Th, Dat, and Mao).
(1) OKR enhancement was observed with increased 440 nm light intensity, while 460 nm and 650 nm light exposures showed initial improvements followed by declines at higher intensities. (2) Retinal thinning in the outer nuclear layer was observed under the most intense (10,000 lx for 14 h) light conditions in the 440 nm and 650 nm groups, while the 460 nm group remained unaffected. (3) Dopamine levels increased with higher intensities in the 440 nm group, whereas the 460 nm group exhibited initial increases followed by decreases. The 650 nm group displayed similar trends but were statistically insignificant compared to the control group. (4) Th expression increased with light intensity in the 440 nm group. Dat showed a rising and then declining pattern, and Mao expression significantly decreased. The 460 nm group exhibited similar patterns for Th and Dat to the behavioral observations, but an inverse pattern for Mao. The 650 nm group presented significant fluctuations in Th and Dat expressions, with pronounced variations in Mao.
Specific red and blue monochromatic light conditions promote visual system development in juvenile zebrafish. However, exceeding these optimal conditions may impair visual function, highlighting the critical role of dopamine pathway in modulating light-induced effects on the visual system.
单色谱光对斑马鱼视觉系统的发育有显著影响，但对其在幼鱼阶段的影响的研究还很缺乏。本研究评估了不同强度和时长的红、蓝光对幼鱼斑马鱼视觉系统和多巴胺通路的影响。
幼鱼斑马鱼在 4 天内分别暴露于红光（650nm）和蓝光（440nm、460nm）下，光强范围为 500-10,000lx，每天 6、10、14 小时。对照组维持在标准实验室条件下。暴露后评估包括视动反应（OKR）、视网膜结构分析、眼多巴胺水平以及与多巴胺通路相关的基因表达（Th、Dat 和 Mao）。
（1）440nm 光强度增加时观察到 OKR 增强，而 460nm 和 650nm 光暴露在更高强度时表现出初始改善，随后下降。（2）在最强烈的光照条件（440nm 和 650nm 组为 10,000lx 持续 14 小时）下，观察到外核层的视网膜变薄，而 460nm 组不受影响。（3）440nm 组多巴胺水平随光强度增加而增加，而 460nm 组则表现出初始增加随后减少的趋势。650nm 组也表现出类似的趋势，但与对照组相比无统计学意义。（4）440nm 组 Th 表达随光强度增加而增加。Dat 表现出先升后降的模式，Mao 表达显著降低。460nm 组的 Th 和 Dat 表现出与行为观察相似的模式，但 Mao 表现出相反的模式。650nm 组 Th 和 Dat 的表达波动显著，Mao 的变化明显。
特定的红、蓝单色谱光条件促进幼鱼斑马鱼的视觉系统发育。然而，超过这些最佳条件可能会损害视觉功能，这突显了多巴胺通路在调节光对视觉系统的影响方面的关键作用。
