Hello, thanks for reading my question.
I'm doing whole cell patch clamp recording with cultured hippocampal neuron. For the neuronal culture, I'm using co-culture system with astrocyte. I cultivate the neuron on top of the astrocyte layer. The neurons looks good and healthy.
However, I'm suffering serious problem. When I go into the whole cell, after the giga seal formation, usually the membrane resistance is quite low, mostly below 80 Mohm, sometimes even below 50 Mohm. Although I got a whole cell with good membrane resistance rarely, the membrane resistance is usually drop to very low resistance quickly, typically within 10 min. For the purpose of my research, I have to maintain the whole cell configuration quite long time, like 30 min.
Increase of access resistance during the experiment is quite usual, as well.
Is there anyone who can give me any advice to solve these problems?
Thank you very much.
Just for your infomation, I'm using NaCl based external solution with bicarbonate buffer system. And for the internal solution, I'm using K-methylsulfate as a main component, but I also tested K-gluconate. The experiment was performed under 35 degree Celcius perfusion chamber.