Neuropeptide, a protein sequence which acts as a hormone or neurotransmitter
The presynaptic terminal bouton is filled with vesicles containing acetylcholine and a neuropeptide called Calcitonin gene-related peptide (CGRP).
Following the isolation of neuropeptide-y (NPY) from the porcine hypothalamus in 1982, researchers began to speculate about the involvement of NPY in hypothalamic-mediated functions.