ANATOMICAL STUDIES OF VISUAL AND SENSORY DEPRIVATION

这项工作的长期目标是为阐明 脊椎动物视觉的结构组织和发育 系统并澄清当它被剥夺时在其中发生的变化 它的正常视觉输入。我们提出的研究直接关系到 胚胎期间视觉系统如何组装的重要问题 发展和各种可能导致的问题 发育异常和感觉剥夺。 在即将到来的授权期内，我们特别建议研究 以下是： (I)鸟类视顶盖的正常发育模式及其 视网膜的神经支配，用~3H-胸腺嘧啶核苷放射自显影和 免疫细胞化学技术，抗顶盖的单抗 抗原，以及一些实验操作，包括180度 翼板和/或中脑的旋转，以及 视网膜进入顶盖。 (Ii)再生雏鸡视顶盖的重组能力 以及单眼早期摘除后的形态可塑性。 (3)感觉超负荷对雏鸡顶盖和顶盖的影响 视网膜离心性纤维的起源核(即所谓的峡部 移植多眼诱发的视神经核离子) 产生“复合”的眼睛。 (四)正常消除异常和异常的因素 雏鸡和仓鼠早期视网膜投射旺盛 视网膜、视神经和视顶盖的操作。 (V)导致离心性轴突“引导”的因素 鸡视网膜和异位或错位的离心神经元的命运。 (Vi)调节视网膜中自然发生的细胞死亡和 离子，特别是活动在神经元维持中的作用 这些结构。

The long term objectives of this work are to contribute to the elucidation of the structural organization and development of the vertebrate visual system and to clarify the changes that occur in it when it is deprived of its normal visual input. The studies we propose bear directly on the important issue of how the visual system is assembled during embryonic development and on the problems that may result from a variety of developmental abnormalities and from sensory deprivation. In the forthcoming grant period we propose specifically to examine the following: (i) The normal pattern of development of the avian optic tectum and its innervation by the retina, using 3H-thymidine autoradiographic and immunocytochemical techniques, monoclonal antibodies raised against tectal antigens, and a number of experimental manipulations including 180 degree rotation of the alar plate and/or midbrain, and the rerouting of the retinal input to the tectum. (ii) The capacity of the regenerated chick optic tectum for reorganization and morphological plasticity following early unilateral eye removal. (iii) The effects of sensory overloading on the chick tectum and the nucleum of origin of centrifugal fibers to the retina (the so-called isthmo optic nucleus-ION) induced by transplanting supernumerary eyes and producing "compound" eyes. (iv) The factors involved in the normal elimination of aberrant and exuberant retinal projections in chicks and hamsters, by early manipulations of the retina, optic nerve and optic tectum. (v) The factors responsible for the "guidance" of centrifugal axons to the chick retina and the fate of ectopic or misplaced centrifugal neurons. (vi) The regulation of naturally-occurring cell death in the retina and ION and especially the role of activity in the maintenance of neurons in these structures.