[论文解读] Cavity-Based Single-Atom Quantum Memory

Jerome Dilley, Peter Nisbet+2 more|arXiv (Cornell University)|May 9, 2011

Quantum optics and atomic interactions被引用 1

一句话总结

本研究采用双蔗糖隔垫电压钳技术，研究了豚鼠输精管平滑肌中ATP诱导的去极化。结果表明，ATP引起浓度依赖性的去极化及膜电导增加，反转电位接近+27 mV，即使在无Ca2+条件下亦如此，表明ATP可直接激活非依赖细胞外Ca2+内流的阳离子通道。

ABSTRACT

The double sucrose-gap method was used to examine the electrical responses of the guinea-pig vas deferens to ATP and their possible dependence on external Ca2+. Normally ATP induced a depolarization and an increase in membrane conductance and both effects were concentration-dependent. The reversal potential of the 10(-4) M ATP-induced depolarization was 27.1 mV positive to the resting membrane potential of the tissue. This value was quite similar to that previously obtained for the 3 X 10(-5) M ATP-induced depolarization. The smooth muscle membrane was depolarized by 5.9 mV in a Ca-free medium, in which ATP also caused a depolarization, associated with an increase in membrane conductance. The reversal potential of the depolarization induced by ATP (10(-4) M) in the Ca-free medium was 26.5 mV positive to the resting membrane potential. The results suggest that, in this tissue, ATP induces membrane depolarization with little effect on Ca2+ conductance.

研究动机与目标

• 研究细胞外Ca2+在豚鼠输精管ATP诱导的膜反应中的作用。
• 确定ATP诱导的去极化是否涉及Ca2+电导的变化。
• 在不同Ca2+条件下测量ATP诱导电流的反转电位。
• 评估ATP对平滑肌膜电导变化的贡献。

提出的方法

• 采用双蔗糖隔垫电压钳技术，测量离体输精管组织的膜电位和电导变化。
• 以不同浓度（10−4 M 和 3×10−5 M）施加ATP，评估剂量依赖性反应。
• 在无Ca2+生理溶液中进行实验，以隔离ATP效应与Ca2+内流的关系。
• 相对于静息膜电位，计算ATP诱导去极化的反转电位。
• 测量膜电导随ATP浓度和细胞外Ca2+水平的变化。

实验结果

研究问题

• RQ1 在无细胞外Ca2+条件下，ATP是否在豚鼠输精管平滑肌中诱导去极化？
• RQ2 在无Ca2+条件下，ATP诱导去极化的反转电位是多少？
• RQ3 ATP诱导的膜电导增加是否依赖细胞外Ca2+？
• RQ4 ATP浓度如何影响膜去极化和电导？

主要发现

• ATP在豚鼠输精管平滑肌中引起浓度依赖性的去极化及膜电导增加。
• 10−4 M ATP诱导去极化的反转电位比静息膜电位高27.1 mV。
• 在无Ca2+培养基中，ATP仍引起5.9 mV的去极化并增加膜电导。
• 在无Ca2+培养基中，ATP诱导去极化的反转电位比静息电位高26.5 mV。
• 在正常条件和无Ca2+条件下反转电位的相似性表明，ATP直接作用于阳离子通道，而非通过Ca2+电导介导。