Tzeng M C, Cohen R S, Siekevitz P
Proc Natl Acad Sci U S A. 1978 Aug;75(8):4016-20. doi: 10.1073/pnas.75.8.4016.
The effect of alpha-latrotoxin on cerebral cortex slices was studied by both biochemical and morphological methods. This toxin greatly stimulates the release of preloaded gamma-amino[3H]butyric acid from cortex slices. The response increases linearly with dose. The release is not dependent on the presence of extracellular Ca2+, and therefore it is not mediated by the release of other transmitters from other types of neurons. In contrast, no significant increase in the release of a nontransmitter substance alpha-amino[14C]isobutyric acid is observed. Since previously we have shown that alpha-latrotoxin stimulated the release of acetylcholine and norepinephrine from cortex slices, it appears that the toxin probably selectively releases all neurotransmitters. The toxin also profoundly depletes the synaptic vesicle population in boutons in the cortex slices. The results suggest that the release of neurotransmitter and the depletion of synaptic vesicle in boutons are manifestations of a single action of the toxin. Therefore, alpha-latrotoxin can be used as a good tool for the identification of neurotransmitters and in studies on the mechanism of neurotransmitter release.
采用生化和形态学方法研究了α- 拉托毒素对大脑皮层切片的作用。这种毒素极大地刺激了预加载的γ-氨基[³H]丁酸从皮层切片中的释放。反应随剂量呈线性增加。这种释放不依赖于细胞外Ca²⁺的存在，因此它不是由其他类型神经元释放其他递质所介导的。相比之下，未观察到非递质物质α-氨基[¹⁴C]异丁酸的释放有显著增加。由于之前我们已经表明α- 拉托毒素刺激了乙酰胆碱和去甲肾上腺素从皮层切片中的释放，看来这种毒素可能选择性地释放所有神经递质。该毒素还能使皮层切片中终扣内的突触小泡数量显著减少。结果表明，神经递质的释放和终扣内突触小泡的减少是毒素单一作用的表现。因此，α- 拉托毒素可作为鉴定神经递质以及研究神经递质释放机制的良好工具。
