Jhaveri S
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139.
Perspect Dev Neurobiol. 1993;1(4):237-43.
A specialized group of radial glial cells constitutes a dorsal raphe in the mesencephalon and serves, at least, in part, to maintain the laterality of the retinotectal projection during development. Disruption of these cells is necessary, but may not be sufficient, for overriding their barrier function. Sulfated proteoglycans localized at the tectal midline form a putative molecular basis for the blockade; however, this blockade is selective: other fiber systems, such as the intertectal axons and under certain conditions the corticotectal axons, can cross the midline. Experimental studies of the tectal midline cells are advancing our understanding of the nature of boundaries in the developing brain.
一组特殊的放射状胶质细胞在中脑构成了中缝背核，至少在一定程度上，其作用是在发育过程中维持视网膜顶盖投射的偏侧性。破坏这些细胞对于克服它们的屏障功能是必要的，但可能并不充分。定位于顶盖中线的硫酸化蛋白聚糖形成了一种假定的分子阻断基础；然而，这种阻断是有选择性的：其他纤维系统，如顶盖间轴突以及在某些条件下的皮质顶盖轴突，能够穿过中线。对顶盖中线细胞的实验研究正在增进我们对发育中大脑边界性质的理解。
