DEVELOPMENT AND REGENERATION OF THE VERTEBRATE RETINA

虽然脊椎动物视网膜的突触和功能组织 虽然已经被很好地理解，但对细胞机制却知之甚少。 调节神经元分化、成熟和突触发生。 我们 最近使用了神经递质特异性的特性，例如摄取， 合成和释放作为生理和解剖探针， 非洲爪蟾和兔中已鉴定的神经元和突触的发育 视网膜 我们发现，对于每一个视网膜递质检查， (GABA甘氨酸和多巴胺）， 特定于发射机的特性遵循特征时间模式。 此外，神经元的承诺，成为GABA能，甘氨酸能 和多巴胺能的表达之前的许多阶段， 目前可用的形态学和生理学标记。 因此，在本发明中， 特定于变送器的属性可能是一个强大的工具， 形态学和化学的早期分化事件以及 神经元的成熟。 因此，在接下来的五年里， 我们计划在未来数年继续进行及扩展这些研究。 主要有6个 目的：（1）胆碱能和某些神经元的发育模式 将对兔视网膜中的肽能神经元进行表征和比较 与GABA能、甘氨酸能和多巴胺能系统的那些相关联。 (2)的 GABA能、甘氨酸能和多巴胺能的分化和成熟 在兔子视网膜中的突触之后， ~ 3 H-递质高亲和力摄取与电镜 放射自显影 (3)突触后的发育模式 这些递质和肽的受体将通过 结合和功能测定。 (4)我们的结果对正常视网膜 发展将被用作研究具体影响的基础， 干扰，例如已识别细胞类型的选择性病变 某些递质和药物的视网膜，以及光-和 黑暗的饲养，对发展的各种transmitter-specific神经元。 (5)胚胎非洲爪蟾视网膜将被解离成单细胞， 在这些细胞中开发发射机特定的特性将是 组织培养。 (6)成年蝾螈的视网膜再生 也将使用神经递质作为探针进行研究。

Although the synaptic and functional organization of the vertebrate retina is fairly well understood, little is known about the cellular mechanisms regulating neuromal differentiation, maturation and synaptogenesis. We have recently used neurotransmitter-specific properties such as uptake, synthesis and release as physiological and anatomical probes to follow the development of identified neurons and synapses in the Xenopus and rabbit retinas. We found that for each of the retinal transmitters examined (GABA, glycine and dopamine), the emergence and maturation of transmitter-specific properties follow a characteristic temporal pattern. Furthermore, the commitments of neurons to become GABAergic, glycinergic and dopaminergic occur many stages prior to the expression of other currently available morphological and physiological markers. Thus, transmitter-specific properties may be powerful tools to follow morphologically and chemically the early events of differentiation as well as maturation of identified neurons. Accordingly, over the next five years, we plan to continue and extend these studies. There are 6 main objectives: (1) The developmental patterns for cholinergic and certain peptidergic neurons in the rabbit retina will be characterized and compared with those of GABAergic, glycinergic and dopaminergic systems. (2) The differentiation and maturation of GABAergic, glycinergic and dopaminergic synapses in the rabbit retina will be followed by a combination of high-affinity uptake of 3H-transmitters and electronic microscope autoradiography. (3) The developmental patterns of the post-synaptic receptors for some of these transmitters and peptides will be examined by binding and functional assays. (4) Our results on normal retinal development will be used as the basis to examine the effects of specific perturbations, such as selection lesion of an identified cell type addition of certain transmitters and drugs to the retinas, as well as light- and dark-rearings, on the development of various transmitter-specific neurons. (5) Embryonic Xenopus retinas will be dissociated into single cells and the development of transmitter-specific properties in these cells will be followed in tissue culture. (6) Retinal regeneration in the adult newt will also be studied using neurotransmitters as probes.