Benes F M, Parks T N, Rubel E W
Brain Res. 1977 Feb 11;122(1):1-13. doi: 10.1016/0006-8993(77)90658-8.
The nucleus laminaris (NL), a third-order brain stem auditory nucleus in birds, receives afferents to its dorsal dendrites from the ipsilateral nucleus magnocellularis (NM), while the ventral dendrites of NL neurons are innervated by axons from the contralateral NM via the crossed dorsal cochlear tract (CTrX). The CTrx was transected in young chickens and, 96 h later, NL was examined for cytological changes. A morphometric analysis of electron micrographs from lesioned and shamd axon terminals were localized almost entirely to the ventral neuropil region of NL. (2) The volume density of dendrite in the ventral region of NL of lesioned animals was reduced by 85% compared to both the dorsal dendritic region of the same animals and the ventral dendritic region of sham-operated control animals. (3) The frequency with which primary dendrites were encountered in the ventral neuropil of lesioned animals was 81% lower than sham-operated controls. (4) Frequently, there was an apparent reduction in the amount of rough endoplasmic reticulum, Golgi apparatus and cytoplasmic granularity in the deafferented part of the NL neurons. (5) The data indicate that the cytological integrity of dendritic processes cna be specifically, profoundly and very rapidly compromised by removing a significant proportion of their afferents, suggesting that a tonic influence may be exerted by the presynaptic terminals.
层状核（NL）是鸟类脑干中的三级听觉核，其背侧树突从同侧的大细胞（NM）接收传入神经，而NL神经元的腹侧树突则由来自对侧NM的轴突通过交叉的背侧耳蜗束（CTrX）支配。在幼鸡中切断CTrX，96小时后，检查NL的细胞学变化。对来自损伤和假手术动物的电子显微镜照片进行形态计量分析。（1）损伤后轴突终末几乎完全定位于NL的腹侧神经毡区域。（2）与同一动物的背侧树突区域和假手术对照动物的腹侧树突区域相比，损伤动物NL腹侧区域的树突体积密度降低了85%。（3）损伤动物腹侧神经毡中初级树突出现的频率比假手术对照低81%。（4）在NL神经元的去传入部分，粗面内质网、高尔基体和细胞质颗粒的数量经常明显减少。（5）数据表明，通过去除相当一部分传入神经，树突过程的细胞学完整性会受到特异性、严重且非常迅速的损害，这表明突触前终末可能发挥了紧张性影响。
