Murakami M, Shimoda Y, Nakatani K, Miyachi E, Watanabe S
Jpn J Physiol. 1982;32(6):927-35. doi: 10.2170/jjphysiol.32.927.
In the isolated, perfused retina of the carp, the effects of GABA and its antagonists, picrotoxin and bicuculline, were investigated on spectral responses of horizontal cells. When the GABA-mediated feedback from horizontal cells to cones was desensitized or blocked by these chemicals, remarkable changes were observed in spectral responses, due to selective suppression of responses to long wavelengths. In particular, the depolarizing responses in the biphasic C-type (H2) cell were abolished, while the hyperpolarizing responses to short wavelengths were retained, resulting in a monophasic spectral response curve. From these results, it was concluded that the GABA-mediated negative feedback plays an essential role in neural mechanisms which convert the trichromatic process at the level of cones into the opponent color process in horizontal cells.
在鲤鱼离体灌注视网膜中，研究了γ-氨基丁酸（GABA）及其拮抗剂印防己毒素和荷包牡丹碱对水平细胞光谱反应的影响。当这些化学物质使GABA介导的从水平细胞到视锥细胞的反馈脱敏或阻断时，由于对长波长反应的选择性抑制，在光谱反应中观察到显著变化。特别是，双相C型（H2）细胞中的去极化反应消失，而对短波长的超极化反应得以保留，从而产生单相光谱反应曲线。从这些结果得出结论，GABA介导的负反馈在将视锥细胞水平的三色过程转化为水平细胞中的拮抗色过程的神经机制中起着至关重要的作用。
