Müller T, Stetter M, Hübener M, Sengpiel F, Bonhoeffer T, Gödecke I, Chapman B, Löwel S, Obermayer K
Department of Computer Science, TU Berlin, Germany.
Neural Comput. 2000 Nov;12(11):2573-95. doi: 10.1162/089976600300014854.
We report an analysis of orientation and ocular dominance maps that were recorded optically from area 17 of cats and ferrets. Similar to a recent study performed in primates (Obermayer & Blasdel, 1997), we find that 80% (for cats and ferrets) of orientation singularities that are nearest neighbors have opposite sign and that the spatial distribution of singularities deviates from a random distribution of points, because the average distances between nearest neighbors are significantly larger than expected for a random distribution. Orientation maps of normally raised cats and ferrets show approximately the same typical wavelength; however, the density of singularities is higher in ferrets than in cats. Also, we find the well-known overrepresentation of cardinal versus oblique orientations in young ferrets (Chapman & Bonhoeffer, 1998; Coppola, White, Fitzpatrick, & Purves, 1998) but only a weak, not quite significant overrepresentation of cardinal orientations in cats, as has been reported previously (Bonhoeffer & Grinvald, 1993). Orientation and ocular dominance slabs in cats exhibit a tendency of being orthogonal to each other (Hubener, Shoham, Grinvald, & Bonhoeffer, 1997), albeit less pronounced, as has been reported for primates (Obermayer & Blasdel, 1993). In chronic recordings from single animals, a decrease of the singularity density and an increase of the ocular dominance wavelength with age but no change of the orientation wavelengths were found. Orientation maps are compared with two pattern models for orientation preference maps: bandpass-filtered white noise and the field analogy model. Bandpass-filtered white noise predicts sign correlations between orientation singularities, but the correlations are significantly stronger (87% opposite sign pairs) than what we have found in the data. Also, bandpass-filtered noise predicts a deviation of the spatial distribution of singularities from a random dot pattern. The field analogy model can account for the structure of certain local patches but not for the whole orientation map. Differences between the predictions of the field analogy model and experimental data are smaller than what has been reported for primates (Obermayer & Blasdel, 1997), which can be explained by the smaller size of the imaged areas in cats and ferrets.
我们报告了对从猫和雪貂的17区通过光学记录得到的方位图和眼优势图的分析。与最近在灵长类动物中进行的一项研究（奥伯迈尔和布拉斯德尔，1997年）类似，我们发现，80%（针对猫和雪貂）的最近邻方位奇点具有相反的符号，并且奇点的空间分布偏离了点的随机分布，因为最近邻之间的平均距离明显大于随机分布所预期的距离。正常饲养的猫和雪貂的方位图显示出大致相同的典型波长；然而，雪貂中奇点的密度高于猫。此外，我们发现了在幼年雪貂中众所周知的主要方位与倾斜方位的过度表征（查普曼和博恩霍费尔，1998年；科波拉、怀特、菲茨帕特里克和珀维斯，1998年），但在猫中只有较弱的、不太显著的主要方位过度表征，正如先前报道的那样（博恩霍费尔和格林瓦尔德，1993年）。猫中的方位板和眼优势板呈现出相互正交的趋势（胡贝纳、肖哈姆、格林瓦尔德和博恩霍费尔，1997年），尽管不如灵长类动物中报道的那样明显（奥伯迈尔和布拉斯德尔，1993年）。在对单只动物的长期记录中，发现随着年龄增长，奇点密度降低，眼优势波长增加，但方位波长没有变化。将方位图与两种方位偏好图的模式模型进行了比较：带通滤波白噪声和场类比模型。带通滤波白噪声预测方位奇点之间的符号相关性，但相关性明显更强（87%的相反符号对），比我们在数据中发现的要强。此外，带通滤波噪声预测奇点的空间分布偏离随机点模式。场类比模型可以解释某些局部斑块的结构，但不能解释整个方位图。场类比模型的预测与实验数据之间的差异比灵长类动物中报道的要小（奥伯迈尔和布拉斯德尔，1997年），这可以用猫和雪貂中成像区域较小来解释。
