Chiba C, Matsushima O, Muneoka Y, Saito T
University of Tsukuba, Institute of Biological Sciences, Ibaraki, Japan.
Brain Res Dev Brain Res. 1997 Feb 20;98(2):204-10. doi: 10.1016/s0165-3806(96)00195-2.
Appearance and maturation of the GABA (gamma-aminobutyric acid) system during newt retinal regeneration were studied by electrophysiological, immunohistochemical, and biochemical techniques. (1) Responses to GABA appeared in neurons dissociated from regenerating retinae before the segregation of the plexiform layers; whereas (2) GABA immunoreactivity appeared at sites of the presumptive horizontal cell and amacrine cell layers at the beginning of the segregation of these layers. During subsequent regeneration, GABA-immunoreactive cells at the amacrine cell layer increased in number and extended lateral processes, forming a GABA-immunoreactive inner plexiform layer. Also GABA immunoreactivity increased in the region of the outer plexiform layer, but not their somata which showed decreased GABA immunoreactivity. (3) GABA synthesis in the retina increased significantly at the beginning of the segregation of the plexiform layers. These results suggest that the increase of GABA synthesis during retinal regeneration correlates well with the development of GABA-immunoreactive cells and that functional GABA receptors appear earlier than increased GABA synthesis.
通过电生理学、免疫组织化学和生物化学技术，研究了蝾螈视网膜再生过程中γ-氨基丁酸（GABA）系统的外观和成熟情况。（1）在神经丛层分离之前，从再生视网膜解离的神经元中就出现了对GABA的反应；而（2）在这些层开始分离时，GABA免疫反应出现在假定的水平细胞和无长突细胞层的部位。在随后的再生过程中，无长突细胞层的GABA免疫反应性细胞数量增加，并伸出横向突起，形成一个GABA免疫反应性的内神经丛层。此外，外神经丛层区域的GABA免疫反应性增加，但其胞体的GABA免疫反应性降低。（3）在神经丛层分离开始时，视网膜中的GABA合成显著增加。这些结果表明，视网膜再生过程中GABA合成的增加与GABA免疫反应性细胞的发育密切相关，并且功能性GABA受体的出现早于GABA合成的增加。
