Kay Alan R, Tóth Katalin
Biological Sciences, 336 BB, Univ. of Iowa, Iowa City, IA 52242, USA.
J Neurophysiol. 2006 Mar;95(3):1949-56. doi: 10.1152/jn.00959.2005. Epub 2005 Nov 30.
The precise role of the high concentration of ionic zinc found in the synaptic vesicles of certain glutamatergic terminals is unknown. Fluorescent probes with their ability to detect ions at low concentrations provide a powerful approach to monitoring cellular Zn2+ levels. In the last few years, a number of fluorescent probes (indicators) have been synthesized that can be used to visualize Zn2+ in live cells. The interpretation of data gathered using such probes depends crucially on the location of the probe. Using acutely prepared hippocampal slices, we provide evidence that the Zn2+ probes, ZnAF-2 and ZP4, are membrane permeant and are able to pass into synaptic vesicles. In addition, we show that changes in fluorescence of the Zn2+ probes can be used to monitor presynaptic activity; however, these changes are inconsistent with Zn2+ release.
在某些谷氨酸能终末的突触小泡中发现的高浓度离子锌的确切作用尚不清楚。具有在低浓度下检测离子能力的荧光探针为监测细胞内锌离子水平提供了一种强大的方法。在过去几年中，已经合成了许多荧光探针（指示剂），可用于在活细胞中可视化锌离子。使用此类探针收集的数据的解释关键取决于探针的位置。通过使用急性制备的海马切片，我们提供证据表明锌离子探针ZnAF-2和ZP4是膜通透性的，并且能够进入突触小泡。此外，我们表明锌离子探针荧光的变化可用于监测突触前活动；然而，这些变化与锌离子释放不一致。
