Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a member of the vasoactive intestinal peptide (VIP)/ secretin/ glucagon superfamily and functions as a hormone, neurohormone, and neurotransmitter in the central nervous system as well as in several peripheral tissues. Recently, several groups including ours have independently produced lines of mice lacking PACAP (PACAP-/-). These mutant mice have not only led to a better understanding of the physiologic roles of endogenous PACAP, but have also revealed some unexpected roles of PACAP. In this paper, phenotypic changes in several brain functions in PACAP-/- mice, including light-induced phase-resetting of the circadian activity rhythm, hippocampal long-term potentiation, and psychomotor behaviors, are reviewed based on the results obtained in our laboratory.
