FMRFamide induces contractions in visceral and somatic musculature as well as in the heart. May play a role as cotransmitters or modulators in a number of significant neuronal systems. Isoform 1 and isoform 2 only share the N-terminal signal sequence. Expressed in 280 cells of the CNS including the EGP heart excitatory motoneurons. Belongs to the FARP (FMRFamide related peptide) family.