PACAP enhanced NMDA currents in mouse SCN neurons. Whole cell patch clamp recording techniques were used to directly measure currents evoked by NMDA in ventral SCN neurons during the night (ZT 15–17). The voltage -dependence of the NMDA-evoked currents was measured by moving the membrane potential of the cell through a series of voltage -steps before, during, and after treatment with NMDA (25 μM) in the bath. By itself, PACAP (10 nM, 240 sec) did not activate voltage-dependent currents, however, PACAP did increase the magnitude of NMDA-evoked currents. Current-voltage relationships for peak current during NMDA treatment recorded using this protocol before and after treatment with PACAP (10 nM).