Umino Yumiko, Solessio Eduardo, Barlow Robert B
Center for Vision Research, Department of Ophthalmology, State University of New York, Upstate Medical University, Syracuse, New York 13210, USA.
J Neurosci. 2008 Jan 2;28(1):189-98. doi: 10.1523/JNEUROSCI.3551-07.2008.
Rods and cones subserve mouse vision over a 100 million-fold range of light intensity (-6 to 2 log cd m(-2)). Rod pathways tune vision to the temporal frequency of stimuli (peak, 0.75 Hz) and cone pathways to their speed (peak, approximately 12 degrees/s). Both pathways tune vision to the spatial components of stimuli (0.064-0.128 cycles/degree). The specific photoreceptor contributions were determined by two-alternative, forced-choice measures of contrast thresholds for optomotor responses of C57BL/6J mice with normal vision, Gnat2(cpfl3) mice without functional cones, and Gnat1-/- mice without functional rods. Gnat2(cpfl3) mice (threshold, -6.0 log cd m(-2)) cannot see rotating gratings above -2.0 log cd m(-2) (photopic vision), and Gnat1-/- mice (threshold, -4.0 log cd m(-2)) are blind below -4.0 log cd m(-2) (scotopic vision). Both genotypes can see in the transitional mesopic range (-4.0 to -2.0 log cd m(-2)). Mouse rod and cone sensitivities are similar to those of human. This parametric study characterizes the functional properties of the mouse visual system, revealing the rod and cone contributions to contrast sensitivity and to the temporal processing of visual stimuli.
视杆细胞和视锥细胞在超过一亿倍的光强度范围内（-6至2 log cd m(-2)）为小鼠视觉提供支持。视杆细胞通路将视觉调节至刺激的时间频率（峰值为0.75 Hz），视锥细胞通路则将视觉调节至刺激的速度（峰值约为12度/秒）。两条通路都将视觉调节至刺激的空间成分（0.064 - 0.128周/度）。通过对视力正常的C57BL/6J小鼠、无功能性视锥细胞的Gnat2(cpfl3)小鼠以及无功能性视杆细胞的Gnat1-/-小鼠的视动反应对比阈值进行二选一的强制选择测量，确定了特定光感受器的贡献。Gnat2(cpfl3)小鼠（阈值为-6.0 log cd m(-2)）在高于-2.0 log cd m(-2)（明视觉）时无法看到旋转光栅，而Gnat1-/-小鼠（阈值为-4.0 log cd m(-2)）在低于-4.0 log cd m(-2)（暗视觉）时失明。两种基因型在过渡性的中间视觉范围内（-4.0至-2.0 log cd m(-2)）都能看见。小鼠视杆细胞和视锥细胞的敏感性与人类相似。这项参数研究表征了小鼠视觉系统的功能特性，揭示了视杆细胞和视锥细胞对对比敏感度以及视觉刺激时间处理的贡献。
