McConnell S K, LeVay S
J Comp Neurol. 1986 Aug 1;250(1):109-32. doi: 10.1002/cne.902500110.
The organization of the retinogeniculocortical visual system of the mink was studied by anterograde and retrograde tracer techniques, by physiological mapping, and by direct recordings from axonal terminals after injection of kainic acid. In the lateral geniculate nucleus, retinogeniculate afferents are segregated according to eye of origin between the two principal layers, A and A1. Within each of these layers there is a further parcellation according to functional type: on-center afferents terminate in the anterior leaflets of A and A1, and off-center afferents in the posterior leaflets. This separation is preserved in area 17: geniculocortical afferents terminate in ocular dominance patches in layer IV, and these patches coexist with an alternating, partially overlapping set of patches for on-center and off-center inputs that we have demonstrated previously (McConnell and LeVay: Proc. Natl. Acad. Sci. USA 81:1590-1593, '84). In both the lateral geniculate nucleus and in area 17, the contralateral eye predominates to a much greater extent than in the cat. Visual cortical areas corresponding to the cat's areas 17, 18, and 19 can be identified in the mink, but they are shifted posterolaterally in the hemisphere, and they show less emphasis on the representation of central retina. Mapping studies also revealed the existence of a fourth visual area in the splenial sulcus (area SV) adjacent to the representation of the far periphery in area 17. This area differs from the corresponding region in the cat in that it receives direct projections from the lateral geniculate nucleus and from areas 17 and 18. The lateral geniculate nucleus projects to each of the four cortical areas that were mapped. The bulk of the projection to area 17 is derived from the principal layers, A and A1, while most cells projecting to areas 18 and SV are found in the C-layer complex. The recurrent projection from area 17 to the lateral geniculate nucleus arises from pyramidal neurons in layer VI, and terminates through all layers of the lateral geniculate nucleus, but most densely in the interlaminar zones. Areas 18 and SV project predominantly to the C layers. Areas 17, 18, and SV are reciprocally connected with the claustrum and the LP-pulvinar complex, and project to the superior colliculus. All four visual cortical areas are mutually interconnected; these associational projections arise from both the supragranular and infragranular layers.
通过顺行和逆行示踪技术、生理图谱绘制以及注射 kainic 酸后对轴突终末的直接记录，对水貂的视网膜 - 膝状体 - 皮质视觉系统的组织进行了研究。在外侧膝状核中，视网膜 - 膝状体传入纤维根据起源眼在两个主要层 A 和 A1 之间分离。在这些层中的每一层内，根据功能类型还有进一步的分区：中心兴奋型传入纤维终止于 A 和 A1 的前小叶，中心抑制型传入纤维终止于后小叶。这种分离在 17 区得以保留：膝状体 - 皮质传入纤维终止于 IV 层的眼优势柱，并且这些柱与我们之前已证明的用于中心兴奋型和中心抑制型输入的交替、部分重叠的柱集共存（McConnell 和 LeVay：美国国家科学院院刊 81:1590 - 1593，'84）。在外侧膝状核和 17 区，对侧眼的优势程度都比猫大得多。在水貂中可以识别出与猫的 17、18 和 19 区相对应的视觉皮质区，但它们在半球中向后外侧移位，并且对中央视网膜代表区的强调较少。图谱绘制研究还揭示在 17 区远周边代表区相邻的胼胝体沟中有第四个视觉区（SV 区）。该区域与猫的相应区域不同之处在于它接受来自外侧膝状核以及 17 和 18 区的直接投射。外侧膝状核投射到所绘制图谱的四个皮质区中的每一个。投射到 17 区的大部分来自主要层 A 和 A1，而投射到 18 区和 SV 区的大多数细胞位于 C 层复合体中。从 17 区到外侧膝状核的反馈投射起源于 VI 层的锥体细胞，并终止于外侧膝状核的所有层，但最密集地分布在层间区。18 区和 SV 区主要投射到 C 层。17、18 和 SV 区与屏状核和 LP - 丘脑枕复合体相互连接，并投射到上丘。所有四个视觉皮质区相互连接；这些联合投射起源于颗粒上层和颗粒下层。
