Figure 5.

A schematic depiction of the stimulus–response relationships for nocturnal Glu (solid line), PACAP + Glu (small dashes), and P6–38 + Glu (large dashes). The arrows indicate the direction of modulation from the Glu response. PACAP induces opposite modulatory effects on Glu in both early and late night from P6–38, which has antagonist effects on PAC1 receptor activation. Note that PACAP moves the effect of Glu down along the amplitude axis whereas P6–38 moves the effect of Glu upward during both phase delay and advance. Subjective night is designated by the horizontal, striped bar.