Mize R R, Luo Q
Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee, Memphis.
Vis Neurosci. 1992 Aug;9(2):157-68. doi: 10.1017/s0952523800009627.
Antibody labeling of the calcium-binding protein calbindin 28kD (CaBP) and gamma-aminobutyric acid (GABA) is altered by short-term monocular deprivation in the lateral geniculate nucleus and visual cortex of adult primates. It is not known whether these alterations occur in other subcortical visual structures. We therefore have examined antibody labeling to CaBP and GABA in the superior colliculus (SC) of visually deprived Rhesus monkeys. One group was monocularly enucleated as adults. The other monkeys experienced different types of monocular and binocular deprivation from birth, including occlusion of one eye, and/or surgically induced aphakia, optically corrected with extended-wear contact lenses, or an intraocular lens implant. Some of these monkeys also had one eye enucleated prior to perfusion. In the SC of normal monkeys, CaBP-immunoreactive neurons formed three laminar tiers within SC, one within the zonal layer (ZL) and upper superficial gray layer (SGL), another bridging the optic and intermediate gray layers, and a third within the deep gray layer. CaBP neurons within the upper tier had small pyriform or stellate morphologies while those in the deeper tiers were slightly larger neurons, most with a stellate morphology. GABA-immunoreactive neurons were densely distributed within the SGL and more sparsely distributed within the deeper layers. These cells were mostly small neurons with horizontal, pyriform, or stellate morphologies. Neither monocular enucleation nor occlusion nor aphakia combined with continuous occlusion of the fellow eye produced any visible reduction in antibody labeling in cells or neuropil within the SC. Full-field measures of labeling intensity (optical density) within the ZL and upper SGL revealed no consistent differences between the SC contralateral or ipsilateral to the affected eye in either CaBP- or GABA-labeled sections. Measures of the optical density, number, and size of labeled neurons also showed no consistent effects of enucleation and/or occlusion. We therefore conclude that the retino-geniculostriate and retino-collicular systems differ in their response to deprivation which is likely due to the significant overlap of retinal axons from the two eyes that occurs in the SC of the Rhesus monkey.
成年灵长类动物外侧膝状体核和视皮层中，钙结合蛋白钙视网膜蛋白28kD（CaBP）和γ-氨基丁酸（GABA）的抗体标记会因短期单眼剥夺而改变。尚不清楚这些改变是否发生在其他皮层下视觉结构中。因此，我们检测了视觉剥夺的恒河猴上丘（SC）中CaBP和GABA的抗体标记。一组成年后单眼摘除眼球。其他猴子从出生起经历了不同类型的单眼和双眼剥夺，包括一只眼睛的遮挡，和/或手术诱发的无晶状体眼，用长戴型隐形眼镜或人工晶状体植入进行光学矫正。这些猴子中的一些在灌注前也摘除了一只眼睛。在正常猴子的上丘中，CaBP免疫反应性神经元在上丘内形成三个分层，一个在带状层（ZL）和上部浅层灰质层（SGL）内，另一个跨越视灰质层和中间灰质层，第三个在深层灰质层内。上层的CaBP神经元具有小的梨形或星形形态，而深层的神经元稍大，大多数具有星形形态。GABA免疫反应性神经元密集分布在SGL内，在较深层内分布较稀疏。这些细胞大多是具有水平、梨形或星形形态的小神经元。单眼摘除、遮挡或无晶状体眼联合对侧眼的持续遮挡，均未使上丘内细胞或神经纤维网中的抗体标记出现任何明显减少。对ZL和上部SGL内标记强度（光密度）的全场测量显示，在CaBP或GABA标记的切片中，患眼对侧或同侧上丘之间没有一致的差异。对标记神经元的光密度、数量和大小的测量也未显示摘除眼球和/或遮挡的一致影响。因此，我们得出结论，视网膜-膝状体-纹状体系统和视网膜-上丘系统对剥夺的反应不同，这可能是由于恒河猴上丘中来自双眼的视网膜轴突存在显著重叠。
