如何理解access resistance和input resistance

从researchgate搜到一个回答，觉得挺不错的，所以就引过来了，防止下次忘记。

https://www.researchgate.net/post/What_is_the_most_efficient_method_to_monitor_input_resistance_and_seal_during_whole-cell_recordings

首先是Pedro Cedras的问题：

What is the most efficient method to monitor input resistance and seal during whole-cell recordings?

然后是Makoto Osanai非常清楚的回答：

It is difficult to measure the exact seal resistance after establishing the whole-cell configuration. But the overall input resistance can be measured. As stated in above Paul's comment, I also used the small hyperpolarizing voltage step. If an amplifier functions of the C-slow compensation and the series resistance compensation are turned off, the amplitude of the initial current peak (Ip) at the onset of the voltage step roughly equal to the current through the series resistance (Rs), and the amplitude of the steady state current (Is) during the voltage step approximately equal to the current through the summation of the series resistance and the input resistance (Ri). (In usual neuron, the current reaches the steady state level within 20 ms.) For example, when -10 mV voltage step was applied, Rs = 10 mV / Ip and (Rs + Ri) = 10 mV / Is. In this case, the input resistance includes the contribution of the seal resistance. In good seal condition, Ri is much smaller than the seal resistance, thus, Ri is equal to the input resistance. In bad seal condition, the seal resistance is decreased and the steady state current is increased. Therefore, if you monitor the current during the small hyperpolarizing voltage step, you can check the condition of the seal.

懂了吗？