Stimulation creates artifacts in some electrodes.

Hello,
I am triying stimulation with a STG4004 and a MEA1060-Inv_BC. I am using the IOcurve_probeTest.tm protocol that is provided by multichannels. The thing is that I have some interferences in the recording electrodes (the the signals seems to be recorded by some electrodes very far from the stimulating one). This thing happens even with or without slice in the chamber. How can I distinghish this from physiological signals? Anyone knows how can I solve this?
Thanks
Ivan

Ps: An example picture can be seen at https://i.servimg.com/u/f49/16/99/81/81/stim_a11.jpg (stimulating electrode is n#84)

Dear Ivan,
this does not look normal. The crosstalk is not even on channels which are next to each other in the hardware. Could you test whether the affected channels are related to the MEA used, and could you also do a test with the test model probe? The only explanation I can think of are salt bridges somewhere on the cirquit board. Please send the results and the serial of your system to support@multichannelsystems.com.

Best Frank MCS