Marchase R B, Barbera A J, Roth S
Ciba Found Symp. 1975;0(29):315-41. doi: 10.1002/9780470720110.ch15.
An assay is described to examine the hypothesis that retinal neurons adhere preferentially to that part of the optic tectum near theri normal synaptic termini. The method measures the adherence of isotopically labelled cell bodies from either the dorsal or ventral half of the neural retina of chick embryos to dorsal and ventral tectum halves. When a labelled cell suspension is prepared from a dorsal half-retina, more cells adhere to the ventral half of the tectum. When the cells are from the ventral part of the retina, more bind to the dorsal half of the tectum. This preferential adhesion mimics the retinotectal projection found in vivo and supports an interpretation of neuronal specificity dependent on cell surface adhesive properties. Molecular mokels are presented that utilize glycosyltransferases and their substrates as the basis for adhesive recognition. Two of these models suggest that quantitative changes in the distribution of transferases and their substrates determine retinotectal specificity. The third proposes qualitative variations in these molecules across the retina and tectum.
本文描述了一种分析方法，用于检验视网膜神经元是否优先粘附于视顶盖中靠近其正常突触终末的部分这一假说。该方法测量来自鸡胚神经视网膜背侧或腹侧半部分的同位素标记细胞体对顶盖背侧和腹侧半部分的粘附情况。当从背侧半视网膜制备标记细胞悬液时，更多细胞粘附于顶盖腹侧半部分。当细胞来自视网膜腹侧部分时，更多细胞则与顶盖背侧半部分结合。这种优先粘附模拟了体内发现的视网膜-顶盖投射，并支持了一种基于细胞表面粘附特性的神经元特异性解释。文中提出了分子模型，这些模型将糖基转移酶及其底物作为粘附识别的基础。其中两个模型表明，转移酶及其底物分布的定量变化决定了视网膜-顶盖特异性。第三个模型则提出这些分子在视网膜和顶盖中的定性差异。
