Corticotropin-releasing factor (CRF) processes in acute and chronic anxiety
This chapter reviews the Corticotropin-releasing factor (CRF) family of peptides as well as the affinity of CRF and CRF-related neuropeptides for CRFR1 and CRFR2, and their second messenger signaling mechanisms. It discusses the localization and regulation of CRF receptors and reviews the evidence that CRF receptors in specific brain regions mediate different, and in some cases opposite, effects on anxiety and affective behavioral responses. Another genetic approach to study deregulation of the CRF system is infusing antisense oligonucleotides into the brain, which suppresses the expression of a ligand or receptor in that specific area. The relationship between the CRF system and development of psychopathologies is dependent on CRF action within brain areas important for behavioral modulation as well as on the endocrine control of anxiety and depression symptoms. Urocortin is considered an endogenous ligand for CRFR1, although it also binds with high affinity to CRFR2.