Peters A, Feldman M L
J Neurocytol. 1976 Feb;5(1):63-84. doi: 10.1007/BF01176183.
Lesions were made in the lateral geniculate nucleus of the rat and the consequent degeneration in area 17 of the cerebral cortex was studied by light and electron microscopy. These lesions produced prominent degeneration of axon terminals in layer IV extending into layer III and a much lesser amount in layers I and VI. The darkened degenerating axon terminals forming asymmetric synaptic junctions and were frequently surrounded by hypertrophied astrocytic processes. These terminals appeared to be disposed randomly, forming no discernible patterns. In layer IV 83% of the synapsing, degenerating terminals formed junctions with dendritic spines, 15% with dendritic shafts, and 2% with neuronal perikarya. The dendritic shafts and neuronal perikarya appeared to belong to spine-free stellate cells. The dendrites giving rise to the spines receiving degenerating axon terminals could not be identified, for most of the spines appeared as isolated profiles that could not be traced back to their dendritic shafts. One example of a degenerating axon terminal synapsing with an axon initial segment was encountered. Small, degenerating myelinated axons were prevalent in layers VI, V and IV, but were only infrequent in the supragranular layers. These results are compared with those obtained in other studies of thalamocortical projections.
在大鼠的外侧膝状核制造损伤，并通过光学显微镜和电子显微镜研究大脑皮质17区随之发生的变性。这些损伤导致IV层的轴突终末显著变性，并延伸至III层，而I层和VI层的变性程度则小得多。变黑的变性轴突终末形成不对称突触连接，并经常被肥大的星形胶质细胞突起所包围。这些终末似乎随机分布，未形成可辨别的模式。在IV层，83%发生突触联系的变性终末与树突棘形成连接，15%与树突干形成连接，2%与神经元胞体形成连接。树突干和神经元胞体似乎属于无棘星形细胞。由于大多数树突棘表现为孤立的形态，无法追溯到其树突干，因此无法识别产生接收变性轴突终末树突棘的树突。遇到一个变性轴突终末与轴突起始段形成突触的例子。小的、变性的有髓轴突在VI层、V层和IV层很常见，但在颗粒上层中很少见。将这些结果与其他丘脑皮质投射研究的结果进行了比较。
