BIOLOGY OF DIFFERENT TYPES OF CELL DEATH IN CHICK EMBRYO SPINAL CORD

神经元存活所需的神经营养因子是通过突触转移的。在这一点上，促进突触形成和维持的机制对于理解神经元死亡的机制至关重要。我们已经证明生物胺促进发育和成年动物中枢神经系统突触的形成和维持，5-羟色胺(5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，5-羟色胺，常规的放射自显影和原位杂交等技术不能很好地定位5HT2A受体的详细分布模式。为了克服这一缺陷，我们提出了针对5HT2A受体蛋白的抗体，并将其用于免疫组织化学。在大鼠大脑皮层，几乎所有神经元都有5HT2a受体的免疫反应。虽然常规技术无法定位5HT2a受体，但生理学研究表明5HT2a受体存在于小脑。通过使用抗体，浦肯野细胞甚至在树突的最远端也被强烈标记。我们在超微结构水平上的免疫组织化学研究表明，在单个突触中，5HT2A受体位于突触后结构的膜厚之下。这些信息和5HT2A型受体一起在脑内的各个区域表达，甚至在超微结构水平上也有表达，并介导5HT2A型受体维持突触结构的功能。

Neurotrophic factors necessary for survival of neurons are transferredacross synapses. In this connection the mechanism to facilitate formation and maintenance of synapses is crucial to understand the mechanism of neuronal death. We have shown that biogenic amines faciliteta synapse formation and maintenance in the central nervous system in developing and adult animals, and that serotonin (5HT)2A receptor mediates the function of 5HT.If it is the case, 5HT2A receptor could be located in a diverse region of brain at the level of single synapses. The conventional techniques such as autoradiography and in situ hybridization are not sensitive enough to locate the detailed distribution pattern of 5HT2A receptor. To overwhelm this drawback we raised antibodies against 5HT2A receptor protein, and utilized them for immunohistochemistry. In rat cerebral cortex virtually all the neurons have immunoreactivity of 5HT2A receptor. Although conventional technique have failed to locate 5HT2A receptor, physiological studies have suggested the presence of 5HT2A receptor in the cerebellum. By using the antibodies Purkinje cells were strongly labelled even in the most distal part of dendrites. Our immunohistochemical study at the ultrastructural level has shown that 5HT2A receptor was located just beneath the membrane thichnings of postsynaptic structure in single synapses. All the informations together 5HT2A receptor are expressed in all the region of brain even at the ultrastructural level, aand mediate the function of 5HT to maintain synaptic structures.