Sclar G, Ohzawa I, Freeman R D
J Neurophysiol. 1985 Sep;54(3):668-75. doi: 10.1152/jn.1985.54.3.668.
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 involved adapting cells to different contrasts (3.1, 12.5, and 50%) while concurrently measuring their contrast-response functions at each of these different levels. 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. 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. 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.(ABSTRACT TRUNCATED AT 250 WORDS)
我们使用正弦波光栅刺激研究了对比度适应对4周龄和6周龄小猫（分别为49个和47个细胞）皮质细胞的影响。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为广泛。我们的实验包括使细胞适应不同的对比度（3.1%、12.5%和50%），同时在这些不同水平下测量它们的对比度反应函数。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（参考文献19）。对比度反应函数沿对数对比度轴横向移动，有效地使细胞的反应范围与当前对比度水平相匹配。这种情况发生的程度因细胞而异。定性和定量评估显示，小猫细胞表现出这些效果的平均程度大于成年猫，4周龄小猫大于6周龄小猫。这表明对适应的敏感性随年龄而变化。我们还进行了其他研究，旨在确定这些适应性效应的位置。首先，我们用标准方案研究了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两眼间传递的程度。（摘要截断于250字）
