Recording of microglial cells with 6-Well MEA

Hello,
I am planning to try to record changes in the field potential generated by microglial cells when opening K channels. My main concern is that cells will be plated in the whole surface of the well, so the charges exchange will be the same in the recording electrodes than in the Ground. How can I solve that? I am thinking in 2 possibilities:
1- reference to the bath: I this case how can I change the configuration so the internal reference of the well is disabled and enable the external reference?
2- reference to the electrodes of anotheer well: I use the standard configuration of the 6-Well MEA, I connect 2 wells with a thin tube filled with medium, add the drugg to open channels to one of the wells and rereference the signal of the channes of this well to the mean of the channels of the other well.

What do you think? Does it make sense for anyone? which option do you recomend?
Thanks
Ivan

Dear Ivan,
to realize option one you just have to remove the connection between pin#15 and the system ground (small black cable, see amplifier manual). Then add an external ground electrode to the well you want to record from. Please note that still all wells are interconnected through the common ground electrode, whether it is connected to the system ground or not.
I think option 2 is unnecessaryly complicated, and because of the common ground I am not sure whether it makes sense.

Frank MCS