动物进化中神经肽样物质和神经系统关系之探讨

The relationship between neuropeptide-like substances and nervous system during evolution

用免疫组织化学方法，研究和追踪神经肽样物质在原生动物、水螅及蝾螈胚胎发育过程中分布的变化，试图探索在动物早期进化过程中神经肽样物质和神经系统之间的关系。实验结果表明：（1）从系统发育看神经肽样物质比神经系统先出现并行使在细胞内的功能。（2）在随后的进化中神经肽样物质先分布于非神经系统部位，如肠道外缘及表皮，并逐渐进入神经系统，这无论从系统发育和个体发育中都能找到依据。（3）在神经系统，神经肽样物质先出现在周边神经，之后；才出现在中枢神经，实验中表明NPY是随着神经嵴细胞的迁移而进入周边神经系统，之后，随着胶质细胞的出现而出现在中枢神经系统。（4）原生动物和蝾螈胚胎均由皮膜或表皮细胞中囊泡状结构直接分泌神经肽祥物质进入胞质内或细胞外。

By immunocytochemical techniques, the localizations of neuropeptide-like substancesof protozoa, hydra and embryos of urodele were investigated with the aim to analyze the relationship between the existence of neuropeptide-like substances and the development of nervous system.The experimental results revealed the following points: (1) From the phylogenetic point of view,the neuropeptide-like substances appeared earlier than the nervous system and performed theirfunctions. (2) During the evolutionary process, the neuropeptide-like substances were first distributed in the non-nervous tissues, like gut epithelium and epidermis,and then in the nervoussystem.This was demonstrated both by phylogenetic and ontogenetic evidences. (3) In the nervous system, the neuropeptide-like substances appeared first in the peripheral system, then in thecentral nervous system.In the experiments of urodelian embryos, it has been found that NPYfollowed the migration of neural crest cells into the peripheral nervous system and then appearedin the central nervous system with the appeaxance of glia cells. (4) In protozoa, as well as inurodelian embryos, the neuropeptide-like substances were produced directly by cortex or vesicularstructures of epidermis into the cytoplasm or outside of the cell.