GRP does not contribute to the summation of excitatory postsynaptic currents (EPSCs). (A) (a) Examples of synaptic responses induced by one train of stimulation containing six pulses delivered at 25 Hz (18 V) at DREZ in the presence of CNQX (25 μM), AP-5 (50 μM), Picrotoxin (100 μM) and Strychine (2 μM). A bath application of a GRPR antagonist (RC3095, 3 μM) was ineffective to the summated EPSCs (Ab). Bottom bars in (a&b) showing stimulation timing. (B) Summary data for A (n = 8, respectively). Red circles show each value.