雏鸡投射向外侧膝状体腹侧核的视顶盖细胞形态研究

鸟类的一些视觉信息经由视顶盖Ⅰ层细胞（Ⅰ细胞）传递到外侧膝状体腹侧核（nucleus geniculatus lateralis ventralis,GLv）,用于色觉、瞳孔反射和视觉运动.使用羰花青荧光染料DiI逆向神经标记技术研究了这些投射向GLv核的视顶盖Ⅰ细胞的形态特征.根据标记细胞的胞体和树突野大小及树突分枝特点,雏鸡投射到GLv核的视顶盖Ⅰ细胞可分为“矛状树突Ⅰ细胞”和“叉状树突Ⅰ细胞”,前者具有小型纺锤状的细胞体和垂直伸延的1支尖端树突,后者具有较大三角形或多角形的细胞体和多支上行性树突.多数标记树突的末端部水平分布于视顶盖F层,和终止于此层的视神经终末部的形态相一致.

Morphological Studies on the Tectal Neurons Which Project to Nucleus Geniculatus Lateralis Ventralis (GLv) in the Chick

Some visual information is sent to the nucleus geniculatus lateralis ventralis(GLv) via the cells in layer I(I cells) of the tectum in birds and is used for color vision,papillary reflex,and kineoptic functions.To reveal the morphological features of 'I cells' which project to GLv,they were retrogradely labeled with cyanine perchlorate DiI in chicks.Two different types of neurons,"spear dendritic I cells" and "forked dendritic I cells" were identified.The former had small spindle soma and an apical dendrite extending to the tectal surface,and the latter had somewhat larger triangular or polygonal soma and plural ascending dendrites.Most of the labeled dendritic endings distributed horizontally in layer F,and showed ending patterns similar to the terminals of optic nerve fibers.