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神经元的内在特性及轴突生长的外在环境是中枢神经系统神经元轴突再生失败的主要原因.外在环境主要由少突胶质细胞、星形细胞及其分泌的细胞外基质和活性因子组成.最近有研究者将胚胎大鼠背根节神经元移植到成年大鼠的胼胝体内,发现这些细胞长出长达10余毫米的轴突,沿脑内白质延伸,从而推断成年动物的正常白质并不完全抑制轴突生长.本研究试图验证中枢神经系统神经元在成年大鼠脑内白质的生长情况.将辣根过氧化物酶注射到出生1天的新生鼠上丘逆行标记视网膜节细胞,3天后将视网膜细胞悬液注入成年大鼠的胼胝体和内囊,存活5、7、9或12天后检查标记的移植细胞的生长情况.发现移植的视网膜节细胞在脑内存活良好,长出多个突起并形成树突样树状结构,部分细胞能观察到单一的轴突样长突起,主要沿白质的纤维走向延伸,在存活9、12天的动物标本,可观察到最长2.5mm的轴突样突起.综合本研究的观察所得,视网膜节细胞在年成年大鼠白质内能长出一定长度的突起,但移植细胞长出的突起不如前述的背根节细胞长出的长,可能由于背根节细胞本身属于外周神经系统及年龄较小,有更强的再生能力;也可能中枢神经系统白质对中枢及外周的神经
The intrinsic characteristics of neurons and the external environment of axon growth are the main reasons for the failure of axon regeneration in the central nervous system.The external environment mainly consists of oligodendrocytes, astrocytes and their secreted extracellular matrix and activity Factor .Recent researchers have embryonic rat dorsal root ganglion neurons transplanted into the corpus callosum of adult rats and found that these cells grow up to 10 mm axons, extending along the brain white matter, thus infer the adult animal Normal white matter does not completely inhibit axonal growth.This study attempts to verify the central nervous system neurons white matter growth in adult rat brain.Radioradical peroxidase was injected into the newborn 1 day old neonatal retrograde labeling of the retina After 3 days, the retinal cell suspension was injected into the corpus callosum and the internal capsule of adult rats and the growth of labeled transplanted cells was examined after 5, 7, 9 or 12 days of survival. The transplanted retinal ganglion cells were found to survive well in the brain, A number of protuberances were formed and a dendritic dendritic structure was formed. Some of the cells could observe a single axon-like protuberance, extending mainly along the fiber of white matter. After the animals survived for 9 and 12 days In this study, observed axillary-like protuberances of up to 2.5 mm, and from the observation of this study, retinal ganglion cells can grow a certain length of protrusions in the white matter of aged adult rats, but the protrusions of the transplanted cells are not as good as the above Dorsal root ganglion cells grow long may be due to the dorsal root ganglion itself belongs to the peripheral nervous system and younger, have a stronger ability to regenerate; may also be the central nervous system white matter to the central and peripheral nerves