%0 Journal Article
%T [Study on the temperature characteristics of fast capacitance in patch clamp experiments].
%A Kong F
%A Li X
%A Jiao R
%A Sun C
%J Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
%V 38
%N 4
%D Aug 2021 25
%M 34459169
暂无%R 10.7507/1001-5515.202007054
%X Patch clamp is a technique that can measure weak current in the level of picoampere (pA). It has been widely used for cellular electrophysiological recording in fundamental medical researches, such as membrane potential and ion channel currents recording, etc. In order to obtain accurate measurement results, both the resistance and capacitance of the pipette are required to be compensated. Capacitance compensations are composed of slow and fast capacitance compensation. The slow compensation is determined by the lipid bilayer of cell membrane, and its magnitude usually ranges from a few picofarads (pF) to a few microfarads (μF), depending on the cell size. The fast capacitance is formed by the distributed capacitance of the glass pipette, wires and solution, mostly ranging in a few picofarads. After the pipette sucks the cells in the solution, the positions of the glass pipette and wire have been determined, and only taking once compensation for slow and fast capacitance will meet the recording requirements. However, when the study needs to deal with the temperature characteristics, it is still necessary to make a recognition on the temperature characteristic of the capacitance. We found that the time constant of fast capacitance discharge changed with increasing temperature of bath solution when we studied the photothermal effect on cell membrane by patch clamp. Based on this phenomenon, we proposed an equivalent circuit to calculate the temperature-dependent parameters. Experimental results showed that the fast capacitance increased in a positive rate of 0.04 pF/℃, while the pipette resistance decreased. The fine data analysis demonstrated that the temperature rises of bath solution determined the kinetics of the fast capacitance mainly by changing the inner solution resistance of the glass pipette. This result will provide a good reference for the fine temperature characteristic study related to cellular electrophysiology based on patch clamp technique.<BR>膜片钳（Patch Clamp）是一种皮安培（pA）级弱电流的测量技术，在基础医学研究中广泛用于细胞电生理记录，如细胞膜电位和离子通道电流的研究等。为了得到准确的离子通道测量结果，需要同时进行微电极的串联阻抗和相关电容补偿。电容补偿包括慢电容补偿和快电容补偿：慢电容源于细胞脂双层，其幅度依细胞大小从几皮法拉（pF）到几微法拉（μF）不等。快电容由玻璃微电极、导线和溶液及接地线等因素决定，幅值在几个皮法拉。一般当微电极完成与细胞的吸附，导线和电极位置确定后，只需在实验前进行一次快、慢电容补偿即可记录到可靠的离子通道电流。但对于伴随溶液温度改变的相关研究来说，细胞浴液的变化是如何影响快电容变化的尚没有报道。本论文在使用膜片钳研究细胞光热效应的实验中，观察到溶液的温升可以改变系统快电容的放电特性。基于此提出了一个考虑温度因素的快电容等效电路，并计算了相关参量变化情况及温度特性。实验数据表明快电容以约 0.04 pF/℃ 的速率随温度增加而增加，而微电极的串联阻抗却随温度增加而减小。进一步分析表明：溶液温度升高对微电极快电容放电时间特性的改变，主要是通过改变微电极内溶液阻抗实现的。这一结果对基于膜片钳技术开展细胞层面的精细温度特性研究有参考意义。.