Isolation of short-wavelength-sensitive cone photoreceptors in 4-6-week-old human infants.
Isolation of short-wavelength-sensitive cone photoreceptors in 4-6-week-old human infants.
复制标题
4-6 周大人类婴儿的短波长敏感锥体光感受器的分离。
DOI：
10.1016/0042-6989(87)90094-0
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发表时间：
1987
期刊：
影响因子：
1.8
通讯作者：
Werner,JS
中科院分区：
文献类型：
--
作者：
Volbrecht,VJ;Werner,JS
光谱灵敏度进行了测量，为9名婴儿，4 - 6周的年龄，和三个成年人的条件下的色适应选择，以揭示存在的短波长敏感锥。单色测试刺激（400 - 550 nm）以叠加在宽带黄色背景上的2 Hz呈现。4分钟后的适应背景，测试刺激，同时记录稳态，视觉诱发皮层电位（VECP）。在每个测试波长的几个辐射水平的响应平均值，并提取的基频的振幅从数字化的响应与快速傅立叶变换。这些数据用于构建每个波长的响应与强度函数。从后一系列函数中选择固定的标准响应，以生成单独的光谱灵敏度曲线。这些VECP光谱灵敏度函数匹配的成年人的心理确定的功能，测量的方法的调整和相同的刺激配置。在这些条件下，婴儿和成人的峰值灵敏度出现在约440 nm处，并且曲线的主瓣（400 - 500 nm）与Vos-Walraven短波长锥基波很好地拟合。婴儿和成人数据之间的唯一主要差异是曲线的次级模式（500 nm以上）的相对灵敏度。这些结果表明，在4 - 6周龄时存在短波长敏感的视锥细胞和视觉皮层的功能通路。
Spectral sensitivity was measured for nine infants, 4–6 weeks of age, and three adults under conditions of chromatic adaptation chosen to reveal the presence of short-wavelength-sensitive cones. Monochromatic test stimuli (400–550 nm) were presented at 2 Hz superimposed on a broadband, yellow background. Following 4 min of adaptation to the background, test stimuli were presented while recording the steady-state, visually-evoked cortical potential (VECP). Response averages were obtained for several radiance levels at each test wavelength, and the amplitude of the fundamental frequency was extracted from the digitized response with a fast-Fourier transform. These data were used to construct response vs intensity functions for each wavelength. A fixed criterion response was chosen from the latter family of functions to generate individual spectral sensitivity curves. These VECP spectral sensitivity functions matched the psychophysically-determined functions of adults, measured by the method of adjustment and with the same stimulus configuration. Peak sensitivity for infants and adults under these conditions occurred at about 440 nm, and the main lobe of the curve (400–500 nm) was well fitted by the Vos-Walraven short-wavelength cone fundamental. The only major difference between the infant and adult data was in the relative sensitivity of the secondary mode of the curves (above 500 nm). These results demonstrate the presence of short-wavelength-sensitive cones and a functional pathway to the visual cortex by 4–6 weeks of age.