Response of retinal terminals to loss of postsynaptic target neurons in the dorsal lateral geniculate nucleus of the adult cat.
Response of retinal terminals to loss of postsynaptic target neurons in the dorsal lateral geniculate nucleus of the adult cat.
复制标题
视网膜末梢对成年猫背外侧膝状核突触后目标神经元丢失的反应。
DOI：
10.1002/cne.903150308
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Sonstein,WJ
中科院分区：
文献类型：
--
作者：
Pearson,HE;Stoffler,DJ;Sonstein,WJ
我们已经使用的神经毒素红藻氨酸产生快速变性的神经元在背外侧膝状体核（dLGN）的成年猫。这种变性模仿膝状体神经元的快速损失后看到的新生儿视觉皮层消融。随后的顺行运输辣根过氧化物酶注射到眼睛被用来揭示在红藻氨酸注射后的不同存活期的视网膜神经节细胞轴突的投射模式。视网膜投射到膝状体退化区域的密度在生存4个月和6个月时显著降低，但在2个月时与正常无显著差异。在研究的任何动物中，膝状体退化区域的层状投影模式均未发生变化，即使相邻层中含有存活细胞。变性dLGN的电子显微镜检查显示完整的视网膜（RLP）和RSD终端在所有的生存时间，虽然终端的密度出现大大降低时相比，对照组。一些RLP终末出现变性的“暗反应”，这些变性终末在存活2个月时数量最多。这些发现表明，成熟的视网膜神经节细胞响应于其通常的靶细胞的变性，将从这些变性区域撤回其轴突终末。我们的结论是，成熟的视网膜神经节细胞继续依赖于目标的完整性，维持正常的轴突分支。
We have used the neurotoxin kainic acid to produce rapid degeneration of neurons in the dorsal lateral geniculate nucleus (dLGN) of the adult cat. This degeneration mimics the rapid loss of geniculate neurons seen after visual cortex ablation in the neonate. Subsequent anterograde transport of horseradish peroxidase injected into the eye was used to reveal the projection patterns of retinal ganglion cell axons at different survival periods after the kainic acid injection. The density of retinal projections to the degenerated regions of the geniculate was reduced considerably at 4 and 6 months survival, but at 2 months was not significantly different from normal. The laminar pattern of projections to degenerated regions of the geniculate did not change in any animals studied, even when an adjacent lamina contained surviving cells. Electron microscopic examination of degenerated dLGN revealed intact retinal (RLP) and RSD terminals at all survival times, although the density of terminals appeared much reduced when compared to controls. Some RLP terminals exhibited the “dark reaction” of degeneration and these degenerating terminals were most numerous at 2 months survival. These findings demonstrate that, in response to degeneration of their usual target cells, mature retinal ganglion cells will withdraw their axon terminals from these regions of degeneration. We conclude that mature retinal ganglion cells continue to be dependent on target integrity for the maintenance of a normal axonal arborization.