The hypothalamo-pituitary-adrenocortical (HPA) axis is recruited by the organism in response to real or perceived threats to homeostasis ("stress"). Regulation of this neuroendocrine system is accomplished by modulation of secretory tone in hypophysiotrophic neurons of the medial parvocellular paraventricular nucleus. Excitation of these neurons is mediated by several sources: direct (and perha...

The hypothalamo-pituitary-adrenal (HPA) axis interacts with the hypothalamo-pituitarygonadal (HPG) axis at several sites and there are both species and stress related differences in how a particular stressor affects the gonadal axis. In the pregnant mare, negative effects of stress on reproduction are often measured in terms of effect on plasma progesterone levels or abortion rate. In cycling m...

The high- and low-avoidance animal (HAA and LAA respectively) strains of Hatano rats were originally selected and bred from Sprague-Dawley rats for their performance in the shuttle-box task. The present study focused on the activity of the hypothalamo-pituitary-adrenocortical (HPA) axis of HAA and LAA rats in response to restraint stress. The restraint stress induced an elevation in plasma conc...

Investigations of peptide precursor processing in nerve cells, including studies on prooxytocin and provasopressin processing in the rat hypothalamo-neurohypophysial system, show that prohormone processing occurs during axonal transport of maturing secretory vesicles. Recent studies (Fricker et al., 1989; Rodriguez et al., 1989) show that carboxypeptidase H (CPH), one of several proteases requi...

BACKGROUND/AIMS Missense, nonsense, and splice mutations in the Fibroblast Growth Factor 8(FGF8) have recently been identified in patients with hypothalamo-pituitary dysfunction and craniofacial anomalies. Here, we report a male patient with a frameshift mutation in FGF8. CASE REPORT The patient exhibited micropenis, craniofacial anomalies, and ventricular septal defect at birth. Clinical eva...

Patients with major depressive disorder (MDD) fiequently exhibit dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis reflected in elevated basal cortisol levels as well as resistance to feedback inhibition, which is typically manifested by resistance to suppression by dexamethasone (Carroll et al 1981; Stokes and Sikes 1988). Alterations in and interactions between the HPA and hypotha...

Ample evidence indicates that in nerve cells, several individual proteins are locally synthesized in postsynaptic domains in dendrites. By contrast, axonal terminals, at least in mammals, are generally thought to lack protein synthetic capacity. However, axonal nerve endings of the hypothalamo-neurohypophyseal tract have recently been shown to contain mRNAs encoding vasopressin, oxytocin, dynor...

Considering the close analogy between the insect median neurosecretory cell (m.n.c.)/ corpus cardiacum (c.c.) complex, and the vertebrate hypothalamo-hypophyseal system (Scharrer & Scharrer, 1944), few studies have been made on the possible hormonal control of water metabolism in insects. In fact, our present knowledge of this aspect is confusing and, in some cases, contradictory (Wall & Ralph,...

The hypothalamo-neurohypophyseal system plays a role in homeostasis under a variety of stress conditions, including endotoxemia. Oxytocin (OXT) and vasopressin (VP) are important hormones synthesized by neurons in the hypothalamic paraventricular and supraoptic nuclei and released into different brain regions and from the neurohypophyseal terminals into the blood in response to many patho-physi...

Neuropeptide Y, a neuropeptide abundantly expressed in the brain, has been implicated in the regulation of the hypothalamo-pituitary-somatotropic axis and the hypothalamo-pituitary-gonadotropic axis. Elevated hypothalamic neuropeptide Y expression, such as that occurs during fasting, is known to inhibit both of these axes. However, it is not known which Y receptor(s) mediate these effects. Here...