Matteau Isabelle, Boire Denis, Ptito Maurice
Department of Psychology, University of Montreal, Québec, Canada, H3C 3J7.
Vis Neurosci. 2003 Sep-Oct;20(5):481-93. doi: 10.1017/s0952523803205022.
The B fragment of cholera toxin (CTb) is a highly sensitive anterograde tracer for the labelling of retinal axons. It can reveal dense retinofugal projections to well-known retinorecipient nuclei along with sparse but distinct input to target areas that are not commonly recognized. Following a unilateral injection of CTb into the vitreous chamber of seven adult cats, we localized the toxin immunohistochemically in order to identify direct retinal projections in these animals. Consistent with previous findings, the strongest projections were observed in the superficial layers of the superior colliculus, the dorsal and ventral lateral geniculate nuclei, the pretectal nuclei, the accessory optic nuclei, and the suprachiasmatic nucleus of the hypothalamus. However, we also found labelled terminals in several other brain areas, including the zona incerta, the medial geniculate nucleus, the lateral posterior-pulvinar complex, the lateral habenular nucleus, and the anterior and lateral hypothalamic regions. The morphological characteristics of the retinal axon terminals in most of the identified novel target sites are described.
霍乱毒素B片段（CTb）是一种用于标记视网膜轴突的高灵敏度顺行示踪剂。它能揭示视网膜向知名视网膜接受核的密集投射，以及向通常未被认识的靶区域的稀疏但明显的输入。在对7只成年猫的玻璃体内进行单侧CTb注射后，我们通过免疫组织化学方法对毒素进行定位，以确定这些动物的直接视网膜投射。与先前的研究结果一致，在中脑上丘浅层、背侧和腹侧外侧膝状体核、顶盖前核、副视核以及下丘脑视交叉上核观察到最强的投射。然而，我们还在其他几个脑区发现了标记终末，包括未定带、内侧膝状体核、外侧后丘脑-丘脑枕复合体、外侧缰核以及下丘脑前区和外侧区。本文描述了在大多数已确定的新靶位点中视网膜轴突终末的形态学特征。
