CONTRAST GAIN-CONTROL IN THE KITTENS VISUAL-SYSTEM
CONTRAST GAIN-CONTROL IN THE KITTENS VISUAL-SYSTEM
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DOI：
10.1152/jn.1985.54.3.668
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发表时间：
1985-01-01
影响因子：
2.5
通讯作者：
FREEMAN, RD
中科院分区：
文献类型：
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作者：
SCLAR, G;OHZAWA, I;FREEMAN, RD
1. 我们使用正弦波光栅刺激研究了对比适应对 4 周和 6 周龄小猫（分别为 49 和 47 个细胞）皮层细胞的影响。我们想知道适应不同对比度水平的影响是否比成年动物更广泛。我们的实验涉及使细胞适应不同的对比度（3.1、12.5 和 50%），同时测量它们在每个不同水平的对比度响应函数。 2. 我们定性地发现，小猫的适应效果与我们之前在成年动物中记录的效果相似 (19)。对比度响应函数沿着对数对比度轴横向移动，有效地将细胞的响应范围与普遍的对比度水平相匹配。这种情况发生的程度因细胞而异。 3. 从定性和定量评估来看，小猫细胞表现出这些效应的平均程度高于成年猫，4 周龄小猫的平均程度高于 6 周龄小猫。这表明适应的敏感性随着年龄的变化而变化。 4. 为了定位这些适应性效应，还进行了其他研究。首先，使用我们的标准方案研究外侧膝状体细胞和纤维（n = 23），其次，我们研究了皮质细胞适应效应在眼间转移的程度。 5. 与前一篇论文 (19) 中提出的成年猫的结果一致，小猫的外侧膝状体神经元未能表现出在皮质细胞中看到的任何适应性效应。此外，我们发现我们测试的大多数（14/17）皮质细胞表现出明显程度的眼间适应转移。这两个结果强烈表明，小猫和成年猫的主要适应部位是视觉皮层。 6. 我们的结果被认为与小猫皮层中发现的适应敏感性增强的可能影响有关。此外，还探讨了对比适应对小猫对比敏感度测量的影响。一种可能性是，成人的对比敏感度水平可能比之前报道的更早发展。
1. We have studied the effects of contrast adaptation on cortical cells from 4- and 6-wk-old kittens (49 and 47 cells, respectively) using sine-wave grating stimuli. We wished to know if the effects of adaptation to different contrast levels are more extensive than those in adult animals. Our experiments involving adapting cells to different contrasts (3.1, 12.5, and 50%) while concurrently measuring their contrast-response functions at each of these different levels. 2. We found qualitatively that the effects of adaptation in the kitten are similar to those we have previously documented in adult animals (19). Contrast-response functions are laterally shifted along the log-contrast axis, effectively matching the response range of the cells to prevailing contrast levels. The degree to which this occurred varied from cell to cell. 3. The average degree to which cells showed these effects, as assessed both qualitatively and quantitatively, was greater for kittens than for adult cats, and greater for 4-wk-old kittens than for those aged 6 wk. This suggests that susceptibility to adaptation varies as a function of age. 4. Additional studies were undertaken with the intent of localizing these adaptive effects. First, lateral geniculate cells and fibers (n = 23) were studied with our standard protocol, and second, we investigated the degree to which the effects of adaptation of cortical cells transferred interocularly. 5. In agreement with the results on adult cats, presented in the preceding paper (19), lateral geniculate neurons in kittens failed to show any of the adaptive effects seen in cortical cells. Additionally we found that most (14/17) of the cortical cells we tested showed a pronounced degree of interocular transfer of adaptation. These two results suggest strongly that the major site of adaptation in the kitten as in the adult, is the visual cortex. 6. Our results are considered in relation to possible implications of the enhanced susceptibility to adaptation found in the kitten cortex. In addition, the influence of contrast adaptation on contrast adaptation on contrast-sensitivity measurements in the kitten is explored. One possibility is that adult levels of contrast sensitivity may develop earlier than has been reported previously.