1. ¹Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
2. ²Center for Behavioral Neuroscience, Emory University, Atlanta, GA, USA
3. ³School of Medicine, Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA

Correspondence: Dr ME Wilson, Yerkes National Primate Research Center, 954 Gatewood Road, Atlanta, GA 30329, USA. E-mail: mark.wilson@emory.edu

Received 6 February 2008; Revised 9 July 2008; Accepted 21 July 2008; Published online 12 August 2008.

Abstract

An increase in corticotropin-releasing factor (CRF) is a putative factor in the pathophysiology of stress-related disorders. As CRF expression in the central nucleus of the amygdala (CeA) is important in adaptation to chronic stress, we hypothesized that unrestrained synthesis of CRF in CeA would mimic the consequences of chronic stress exposure and cause dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, increase emotionality and disrupt reproduction. To test this hypothesis, we used a lentiviral vector to increase CRF-expression site specifically in CeA of female rats. Increased synthesis of CRF in CeA amplified CRF and arginine vasopressin peptide concentration in the paraventricular nucleus of the hypothalamus, and decreased glucocorticoid negative feedback, both markers associated with the pathophysiology of depression. In addition, continuous expression of CRF in CeA also increased the acoustic startle response and depressive-like behavior in the forced swim test. Protein levels of gonadotropin-releasing hormone in the medial preoptic area were significantly reduced by continuous expression of CRF in CeA and this was associated with a lengthening of estrous cycles. Finally, sexual motivation but not sexual receptivity was significantly attenuated by continuous CRF synthesis in ovariectomized estradiol-progesterone-primed females. These data indicate that unrestrained CRF synthesis in CeA produces a dysregulation of the HPA axis, as well as many of the behavioral, physiological and reproductive consequences associated with stress-related disorders.