Represa A, Tremblay E, Ben-Ari Y
Neuroscience. 1987 Mar;20(3):739-48. doi: 10.1016/0306-4522(87)90237-5.
The regional distribution of high affinity binding sites for kainic acid has been determined in rat hippocampi by quantitative autoradiography. Selective lesions were made in order to determine the exact localization of these sites in the mossy fiber system, and to evaluate whether the sprouting and synaptic reorganization of the mossy fibers are associated with alterations in the distribution of these binding sites. The results show that kainate binding sites in the stratum lucidum are more vulnerable to destruction of the granules and their mossy fibers by intrahippocampal colchicine injections than to destruction of the CA3/CA4 pyramidal cells by injection of kainate into the amygdala. This suggests that a substantial proportion of the kainate binding sites is associated with the mossy fiber terminals (i.e. the presynaptic elements). Furthermore, in keeping with an earlier study, destruction of the pyramidal neurons of CA3 by intracerebral kainate produced a dark Timm positive band in the supragranular zone which is due to the sprouting of mossy fibers. This was associated with an increase in the density of kainate binding sites, which further stresses the parallelism between the distribution of these sites and mossy fiber terminals.
通过定量放射自显影法已确定了大鼠海马中对 kainic 酸高亲和力结合位点的区域分布。为了确定这些位点在苔藓纤维系统中的精确位置，并评估苔藓纤维的发芽和突触重组是否与这些结合位点分布的改变相关，进行了选择性损伤。结果表明，与通过向杏仁核注射 kainate 破坏 CA3/CA4 锥体细胞相比，海马内注射秋水仙碱破坏颗粒及其苔藓纤维时，透明层中的 kainate 结合位点更易受到破坏。这表明相当一部分 kainate 结合位点与苔藓纤维终末（即突触前成分）相关。此外，与早期研究一致，脑内注射 kainate 破坏 CA3 的锥体细胞会在颗粒上层区域产生一条深色的 Timm 阳性带，这是由于苔藓纤维发芽所致。这与 kainate 结合位点密度的增加相关，这进一步强调了这些位点的分布与苔藓纤维终末之间的平行关系。
