PACAP enhances the frequency and amplitude of sEPSCs recorded from mouse SCN neurons. Whole cell patch clamp recording techniques were used to measure the sEPSCs in ventral SCN neurons during the night (ZT 15–17). All experiments were carried out in presence of TTX (0.5 μM) and bicuculline (25 μM). (A) Top panel provides an example of sEPSCs recorded before and after treatment with PACAP (10 nM, 240 sec). PACAP increased the frequency (4 out of 6 neurons) and the amplitude (6 out of 6 neurons) of the sEPSCs. (B) Average sEPSC waveform recorded in an SCN neuron before and after treatment with PACAP (10 nM, 240 sec). PACAP increased the sEPSC amplitude by 20% ± 5 %.