I am doing field recordings experiments at CA3 CA1 synapses in the hippocampus.
I noticed that when I do the input output relationship I often see that the presynaptic fiber volley is higher than the fEPSP, in spite of the amplitude of the fEPSP which is quite good ( 1 to 3 mv) . I am not having problems in doing LTP experiments but I want to know if this big volley maybe a problem or something similar.
I am using a DS3 current stimulator and a bipolar stimulating electrode by FHC.
Thanks a lot