Vitanova L, Kupenova P, Popova E, Mitova L
Department of Physiology, Medical Faculty Sofia, Bulgaria.
Acta Physiol Scand. 1997 Mar;159(3):227-35. doi: 10.1046/j.1365-201X.1997.596346000.x.
The aim of the present work was to investigate the role of GABA and glycine, the two main inhibitory neurotransmitters in the retina, in the spectral sensitivity coding under conditions of light adaptation. To study this question, spectral sensitivity curves, based on the turtle ERG responses to stimuli of different wavelengths, were constructed. The spectral sensitivity curves. obtained before and during treatment with picrotoxin (PT), a GABAA antagonist, or with strychnine (ST), a glycine antagonist, were compared. Both PT and ST increased the b- and d-wave absolute sensitivity in a wavelength-dependent manner. PT significantly changed the shape of the b- and d-wave spectral sensitivity curves and the latter lost their peaks. It is concluded that, under conditions of light adaptation, GABA and glycine took part in the formation of the b- and d-wave spectral sensitivity curves, that both of them exerted an effect on the gain and that furthermore,GABA had a well pronounced effect on the tuning of the spectral sensitivity curves.
本研究的目的是探讨视网膜中两种主要的抑制性神经递质γ-氨基丁酸（GABA）和甘氨酸在明适应条件下对光谱敏感性编码中的作用。为了研究这个问题，基于乌龟视网膜电图（ERG）对不同波长刺激的反应构建了光谱敏感性曲线。比较了在用GABAA拮抗剂印防己毒素（PT）或甘氨酸拮抗剂士的宁（ST）处理之前和处理过程中获得的光谱敏感性曲线。PT和ST均以波长依赖性方式增加了b波和d波的绝对敏感性。PT显著改变了b波和d波光谱敏感性曲线的形状，并且后者失去了峰值。得出的结论是，在明适应条件下，GABA和甘氨酸参与了b波和d波光谱敏感性曲线的形成，它们都对增益产生影响，此外，GABA对光谱敏感性曲线的调谐有明显作用。
