Qu Jia, Zhou Xiangtian, Zhang Luanling, Ni Hailong, Ashwell Ken, Lu Fan
School of Ophthalmology & Optometry, Wenzhou Medical College, Wenzhou 325003, China.
Zhonghua Yan Ke Za Zhi. 2002 Sep;38(9):517-9.
To reveal the morphological features and dynamic processes of the development of inter-connections in the retina, lateral geniculate nucleus (LGN), superior colliculus (SC) and visual cortex (VC) in human fetal life by using a fluorescent tracer, 1, 1'-dioctadecyl-3, 3, 3', 3'-tetramethylin-docarbocyanine perchlorate (DiI).
DiI was embedded into the optic tract, brachium of superior colliculus and subplate of visual cortex in fixed postmortem human tissues of 7 fetuses. The tissue was incubated at 37 degrees C for 4 to 10 weeks (ws). After DiI had satisfactorily diffused via axons of the visual system, the tissue was sectioned, mounted and observed under a confocal laser scanning microscope.
In 12 week-fetus, retinogeniculate axon has already reached LGN, but there was no cellular lamination. After embedment, axons from retina arrived at SC, and the fibers were distributed along the dorsal part of the SC. At 12 and 22 ws, there were subplates under visual cortex.
The retinogeniculate axon reaches LGN before 12 ws and forms cellular lamination after 12 ws. The axon from retina reaches SC before 12 ws. The subplate under visual cortex forms before 12 ws and disappears after 22 ws. DiI can be easily and effectively used to label the axon of visual system of human fetus to study the prenatal development of human visual pathway.
通过使用荧光示踪剂1,1'-二油酰基-3,3,3',3'-四甲基吲哚菁高氯酸盐（DiI），揭示人类胎儿期视网膜、外侧膝状体（LGN）、上丘（SC）和视觉皮层（VC）中连接发育的形态特征和动态过程。
将DiI嵌入7例胎儿固定的尸检人体组织的视束、上丘臂和视觉皮层的板下层。组织在37℃下孵育4至10周（ws）。当DiI通过视觉系统的轴突充分扩散后，将组织切片、固定并在共聚焦激光扫描显微镜下观察。
在12周龄胎儿中，视网膜膝状体轴突已到达LGN，但尚无细胞分层。植入后，来自视网膜的轴突到达SC，纤维沿SC的背侧部分分布。在12周和22周ws时，视觉皮层下有板下层。
视网膜膝状体轴突在12周ws前到达LGN，并在12周ws后形成细胞分层。来自视网膜的轴突在12周ws前到达SC。视觉皮层下的板下层在12周ws前形成，并在22周ws后消失。DiI可轻松有效地用于标记人类胎儿视觉系统的轴突，以研究人类视觉通路的产前发育。
