ADCYAP1 and Anxiety: PACAP has been implicated in central processes such as development of anxiety behavior (Mustafa, 2013) and circadian rhythms (Mertens et al., 2007) and, importantly, both the ligand and the receptor are present in a number of metabolic and reproductive nuclei in the hypothalamus, including the ventromedial hypothalamus (VMH) (Vaudry et al., 2000).