Corticoliberin (CRH, aka corticotropin-releasing factor CRF) is a 41-amino acid amino peptide which, together with CRH-related peptides such as the urocortins (UCNs), plays a role in coordinating endocrine, autonomic and behavioral responses to stress. These peptides exert their effects through binding and activation of two class B/Secretin family of GPCRs, CRHR1 and CRHR2 (aka CRFR1 and CRFR2 respectively). The activity of these receptors is mediated by coupling to the G protein alpha s subunit, stimulating adenylyl cyclase which increases intracellular cAMP levels (Donaldson et al. 1996). CRH and UCN bind with highest affinity to both CRHR1 and CRHR2 receptors but CRHR2-beta receptors can also bind UCN2 and UCN3 (Pal et al. 2010).