Tychsen L, Burkhalter A, Boothe R G
Department of Ophthalmology, Washington University School of Medicine, St. Louis, Missouri, USA.
Klin Monbl Augenheilkd. 1996 Jan;208(1):18-22. doi: 10.1055/s-2008-1035162.
To investigate the structural basis for functional deficits in infantile strabismus we used a neuroanatomic tracer and a histochemical label to examine the primary visual cortex (area V1) of adult esotropic macaque monkeys.
The animals had developed natural esotropia in the first months of life, alternated fixation, and exhibited the ocular motor signs that typify strabismus with onset in infancy. After behavioral and VEP testing, ocular dominance columns (ODCs) in V1 were injected with a neuronal traser and labeled for cytochrome oxidase activity.
The strabismic monkeys showed striking deficits in binocular luminance visually-evoked potentials (VEPs) and characteristic directional asymmetries in motion VEPs. Binocular horizontal connections between ODCs were reduced an average of 50-60% in strabismic as compared to normal monkeys. ODCs also showed unequal metabolic activity with contralaterally (i.e. nasal retina) driven ODCs showing greater activity in each V1.
The maldevelopment of connections in upper V1 layers correlates with the abnormalities in binocular and motion VEPs. The unequal metabolic activity suggests interocular suppression. These results provide the first neuroanatomic evidence for cerebral cortex maldevelopments in natural infantile esotropia.
为了研究婴儿斜视功能缺陷的结构基础，我们使用神经解剖示踪剂和组织化学标记物来检查成年内斜视猕猴的初级视皮层（V1区）。
这些动物在出生后的头几个月就出现了自然内斜视，交替注视，并表现出典型的婴儿期起病的斜视眼动体征。在进行行为和视觉诱发电位（VEP）测试后，向V1区的眼优势柱（ODC）注射神经元示踪剂，并标记细胞色素氧化酶活性。
斜视猕猴在双眼亮度视觉诱发电位（VEP）方面表现出明显缺陷，在运动VEP方面表现出特征性的方向不对称。与正常猕猴相比，斜视猕猴的ODC之间的双眼水平连接平均减少了50%-60%。ODC还表现出代谢活动不均等，对侧（即鼻侧视网膜）驱动的ODC在每个V1区表现出更强的活性。
V1区上层连接的发育异常与双眼和运动VEP的异常相关。代谢活动不均等提示眼间抑制。这些结果为自然婴儿内斜视的大脑皮层发育异常提供了首个神经解剖学证据。
