LeVay S, McConnell S K, Luskin M B
J Comp Neurol. 1987 Mar 15;257(3):422-41. doi: 10.1002/cne.902570310.
The functional organization of geniculocortical afferents and the visual responses of neurons in primary visual cortex (area 17) were studied in barbiturate-anesthetized, paralyzed minks and cats. Responses of the afferents were studied after silencing intrinsic cortical activity with injections of kainic acid. In both species, afferents were segregated into patches on the basis of eye of origin. In the mink, but not in the cat, there was a further segregation on the basis of center type, with on- and off-center afferents terminating in alternating, partially overlapping patches. The visual responses of cortical neurons in the mink showed many similarities to those in the cat. Nearly all units were orientation-selective, and there was a columnar organization for preferred orientation. Many units were selective for one direction of movement. Within the binocular segment of cortex, although many units could be driven from either eye, there was a marked bias toward the contralateral eye compared to the cat. There was a columnar system for ocular dominance, but contralateral eye columns were wider than ipsilateral. In both species, a quantitative study was made of the responses of cortical neurons to stationary, flashing slits as a function of position in the receptive field. In the mink, and less clearly in the cat, units could be identified as simple or complex on the basis of the spatial separation or overlap of "on" and "off" discharge zones. In both species, simple cells were found most commonly in layers IV and VI, while layer V contained the greatest proportion of complex cells. The relative strengths of the on and off discharges of single cells were also measured. In the mink, many units gave better overall responses to the on or off phase of the stimulus, and 15% showed a strong (greater than 9:1) preference for one or the other, compared to 4% in the cat. In the mink, units with a common preference for the on or off phase of stationary stimuli were arranged in columnar aggregates, a feature of cortical organization that was not found in the cat. These columns probably result from the partial segregation of on-center and off-center geniculate afferents within layers IV and VI of the mink's cortex. On-dominated columns were, however, wider or more numerous than off-dominated columns.
在巴比妥酸盐麻醉、麻痹的水貂和猫身上，研究了膝状体皮质传入纤维的功能组织以及初级视觉皮层（17区）中神经元的视觉反应。在用注射 kainic 酸使皮质内在活动沉默后，研究了传入纤维的反应。在这两个物种中，传入纤维根据起源眼被分隔成斑块。在水貂中，但在猫中没有，基于中心类型有进一步的分隔，开中心和闭中心传入纤维终止于交替的、部分重叠的斑块中。水貂皮质神经元的视觉反应与猫的视觉反应有许多相似之处。几乎所有单位都是方向选择性的，并且存在首选方向的柱状组织。许多单位对一个运动方向具有选择性。在皮质的双眼段内，尽管许多单位可以由任何一只眼睛驱动，但与猫相比，对侧眼有明显的偏向。存在一个眼优势柱状系统，但对侧眼柱比同侧眼柱宽。在这两个物种中，对皮质神经元对静止、闪烁狭缝的反应进行了定量研究，作为感受野中位置的函数。在水貂中，在猫中不太明显，可以根据“开”和“关”放电区的空间分离或重叠将单位识别为简单或复杂单位。在这两个物种中，简单细胞最常见于第IV层和第VI层，而第V层包含最大比例的复杂细胞。还测量了单个细胞的开和关放电相对强度。在水貂中，许多单位对刺激的开或关阶段给出更好的总体反应，15% 的单位对其中一个表现出强烈（大于 9:1）的偏好，而在猫中为 4%。在水貂中，对静止刺激的开或关阶段有共同偏好的单位排列成柱状聚集体，这是猫皮质组织中未发现的一个特征。这些柱可能是由于水貂皮质第IV层和第VI层内开中心和闭中心膝状体传入纤维的部分分隔所致。然而，开主导柱比闭主导柱更宽或更多。
