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Chronic stress precipitates pronounced enhancement of central stress excitability, marked by sensitization of hypothalamic-pituitary-adrenocortical (HPA) axis responses and increased adrenocorticotropic hormone (ACTH) secretagogue biosynthesis in the paraventricular nucleus of the hypothalamus (PVN). Chronic stress-induced enhancement of HPA axis(More)
BACKGROUND Stress-related disorders (e.g., depression) are associated with hypothalamic-pituitary-adrenocortical axis dysregulation and prefrontal cortex (PFC) dysfunction, suggesting a functional link between aberrant prefrontal corticosteroid signaling and mood regulation. METHODS We used a virally mediated knockdown strategy (short hairpin RNA(More)
Adolescent development is proposed to represent a time of increased susceptibility to stress. During adolescence, the brain demonstrates a high level of plasticity and can be positively or negatively affected by the environment. This study tests the hypothesis that adolescent development is a stage of enhanced vulnerability to chronic stress. Male(More)
The goal of this study was to explore mechanisms that mediate hypersecretion of LH and progressive loss of cyclicity in female sheep exposed during fetal life to excess testosterone. Our working hypothesis was that prenatal testosterone excess, by its androgenic action, amplifies GnRH-induced LH (but not FSH) secretion and, thus, hypersecretion of LH in(More)
Life stress frequently occurs within the context of homeostatic challenge, requiring integration of physiological and psychological need into appropriate hormonal, cardiovascular, and behavioral responses. To test neural mechanisms underlying stress integration within the context of homeostatic adversity, we evaluated the impact of a pronounced(More)
Chronic stress is associated with dysregulation of energy homeostasis, but the link between the two is largely unknown. For most rodents, periods of chronic stress reduce weight gain. We hypothesized that these reductions in weight are an additional homeostatic challenge, contributing to the chronic stress syndrome. Experiment #1 examined cardiovascular(More)
Proper integration and execution of the physiological stress response is essential for maintaining homoeostasis. Stress responses are controlled in large part by the paraventricular nucleus (PVN) of the hypothalamus, which contains three functionally distinct neural populations that modulate multiple stress effectors: (1) hypophysiotrophic PVN neurons that(More)
Chronic stress produces numerous adaptations within the hypothalamic-pituitary-adrenal (HPA) axis that persist well after cessation of chronic stress. We previously demonstrated profound attenuation of HPA axis responses to novel environment 4-7 days following chronic stress. The present study tests the hypothesis that this HPA axis hyporesponsivity is(More)
Chronic variable stress (CVS) exposure modifies the paraventricular nucleus of the hypothalamus (PVN) in a manner consistent with enhanced central drive of the hypothalamo-pituitary-adrenocortical (HPA) axis. As previous reports suggest that post-stress enhancement of norepinephrine (NE) action contributes to chronic stress regulation at the level of the(More)
Hypoglycemia initiates the counter-regulatory response (CRR), in which the sympathetic nervous system, glucagon and glucocorticoids restore glucose to appropriate concentrations. During starvation, low leptin levels restrain energy utilization, enhancing long-term survival. To ensure short-term survival during hypoglycemia in fasted animals, the CRR must(More)