Anderson R E, Hollyfield J G
J Cell Biol. 1984 Aug;99(2):686-91. doi: 10.1083/jcb.99.2.686.
The absorption of light by photoreceptor cells leads to an increased incorporation of [2-3H]inositol into phosphoinositides of horizontal cells in the retina of Xenopus laevis in vitro. We have identified several retinal neurotransmitters that are involved in regulating this response. Incubation with glycine, the neurotransmitter of an interplexiform cell that has direct synaptic input onto horizontal cells, abolishes the light effect. This inhibition is reversed by preincubation with strychnine. Acetylcholine added to the culture medium enhances the incorporation of [2-3H]inositol into phosphoinositides in horizontal cells when retinas are incubated in the dark. This effect is inhibited by preincubation with atropine. However, atropine alone does not inhibit the light-enhanced incorporation of [2-3H]inositol into phosphoinositides in the retina. gamma-Aminobutyric acid, the neurotransmitter of retinal horizontal cells in X. laevis, as well as dopamine and norepinephrine, have no effect on the incorporation of [2-3H]inositol into phosphoinositides. These studies demonstrate that the light-enhanced incorporation of [2-3H]inositol into phosphoinositides of retinal horizontal cells is regulated by specific neurotransmitters, and that there are probably several synaptic inputs into horizontal cells which control this process.
在体外培养的非洲爪蟾视网膜中，光感受器细胞对光的吸收会导致[2-³H]肌醇更多地掺入水平细胞的磷酸肌醇中。我们已经鉴定出几种参与调节这种反应的视网膜神经递质。与甘氨酸（一种对水平细胞有直接突触输入的网间细胞的神经递质）共同孵育会消除光效应。用士的宁预孵育可逆转这种抑制作用。当视网膜在黑暗中孵育时，添加到培养基中的乙酰胆碱会增强[2-³H]肌醇掺入水平细胞磷酸肌醇中的量。用阿托品预孵育可抑制这种效应。然而，单独使用阿托品并不会抑制视网膜中光增强的[2-³H]肌醇掺入磷酸肌醇的过程。γ-氨基丁酸（非洲爪蟾视网膜水平细胞的神经递质）以及多巴胺和去甲肾上腺素，对[2-³H]肌醇掺入磷酸肌醇均无影响。这些研究表明，光增强的[2-³H]肌醇掺入视网膜水平细胞磷酸肌醇的过程受特定神经递质调节，并且水平细胞可能有几种突触输入来控制这一过程。
