Long-term eye exposure to ultraviolet (UV)A can effect memory and learning ability. However, the underlying mechanism behind these effects remain unknown. In this study, we used HR-1 mice to study effects of long-term UVA eye irradiation. The eyes or dorsal skin of the mice were exposed to UVA at the dose of 110kj/m2 using an FL20SBLB-A lamp three times a week over 12 months. We measured the levels of reactive oxygen species, corticotropin-releasing hormone (CRH), urocortin 2, and CRH type 2 receptor (CRHR-2) in the brain of treated and control animals. Their memory and learning ability following exposure to UVA was analyzed by the standard water maze test. Our results showed that the levels of reactive oxygen species, CRH, urocortin 2, and CRHR-2 increased significantly following long-term UVA irradiation, and the effects were more pronounced in animals subjected to eye irradiation than those subjected to dorsal skin irradiation. Furthermore, the UVA exposure led to an increase in the levels of β-amyloid and microglia in the brain. These results indicated that UVA eye irradiation potentially mediated a decline in memory and learning ability via enhancing levels of urocortin 2, microglia, and β-amyloid in the brain.

中文翻译：

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长期暴露于眼睛的 UVA 会通过促肾上腺皮质激素释放激素 2 型受体损害小鼠的记忆力和学习能力。

眼睛长期暴露在紫外线 (UV)A 下会影响记忆力和学习能力。然而，这些影响背后的潜在机制仍然未知。在这项研究中，我们使用 HR-1 小鼠来研究长期 UVA 眼睛照射的影响。在 12 个月内，使用 FL20SBLB-A 灯每周 3 次将小鼠的眼睛或背部皮肤暴露于 110kj/m2 剂量的 UVA。我们测量了治疗和对照动物大脑中活性氧、促肾上腺皮质激素释放激素 (CRH)、尿皮质素 2 和 CRH 2 型受体 (CRHR-2) 的水平。他们在暴露于 UVA 后的记忆和学习能力通过标准水迷宫测试进行分析。我们的结果表明，活性氧、CRH、尿皮质素 2 和 CRHR-2 的水平在长期 UVA 照射后显着增加，与接受背部皮肤照射的动物相比，接受眼睛照射的动物的效果更明显。此外，UVA 暴露导致大脑中 β-淀粉样蛋白和小胶质细胞水平的增加。这些结果表明，UVA 眼睛照射可能通过提高大脑中尿皮质素 2、小胶质细胞和 β-淀粉样蛋白的水平来介导记忆力和学习能力的下降。