视网膜水平细胞的内在光响应的teleosts
Ning Cheng1, Takashi Tsunenari, King-Wai Yau
1Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. chengn2@mail.nih.gov
Nature
|July 28, 2009
概括
鱼类的水平细胞具有内在的光敏感性,通过缓慢的电流调节对光作出反应. 这一发现揭示了非棒,非形光受体,有助于脊椎动物的图像形成视力.
科学领域:
- 神经科学是一个神经科学.
- 视觉科学 视觉科学 视觉科学
- 摄影生物学 摄影生物学
背景情况:
- 发现内在光敏感的视网膜质细胞挑战了传统的看法,即棒和是视网膜唯一的光受体.
- 本质上光敏感的视网膜质细胞利用黑色素光色素用于非图像形成的视觉功能,如昼夜节律调节.
- 鱼视网膜水平细胞中的黑色素存在表明这些神经元中潜在的内在光敏感性,这对于视觉处理至关重要.
研究的目的:
- 为了研究鱼类水平细胞是否表现出内在的光敏感性.
- 描述鱼类水平细胞中任何光感应反应的性质和动力学.
- 确定分子基础,特别是黑色素表达,潜在的水平细胞光敏感性.
主要方法:
- 从单个,急性分离的鱼和金鱼水平细胞中记录光感应的反应.
- 分析电压电流及其通过光的调制.
- 克隆鱼黑色素和脊椎动物古老的 (VA) 素基因.
- 在现场杂交以在鱼视网膜中定位黑色素和VA光素的表达.
主要成果:
- 鱼圆水平细胞,但不是横杆水平细胞,表现出缓慢的,光诱导的对尼菲迪平敏感电流的调制,持续数分钟.
- 很大一部分金鱼的水平细胞表现出类似的缓慢光反应.
- 鱼表达了黑色素基因,在现场杂交将黑色素表达局部化到水平细胞层,与VA opsin不同.
结论:
- 鱼的水平细胞具有内在的光敏感性,由黑色素介导.
- 横向细胞中的这种内在光响应可能会在延长的时间范围内调节横向抑制.
- 脊椎动物拥有视网膜非棒/非形光受体,它们有助于图像形成视觉.
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