Cortisol and ACTH response to Dex/CRH testing and 24-hour urine free cortisol levels in women with and without premenstrual dysphoric disorder.

Hyperactive and hyperreactive HPA axis functions are frequently reported in depressive disorders, particularly in major depression. However, research into HPA axis function in women with premenstrual dysphoric disorder (PMDD), which is also classified as a depressive disorder, has shown inconsistent results. This study aimed to characterize the HPA axis in women with PMDD using the combined dexamethasone suppression and CRH stimulation (Dex/CRH) test, alongside measurements of 24-hour urine free cortisol (UFC).

Lectin binding and gel secretion within Lorenzinian electroreceptors of Polyodon.

We imaged the carbohydrate-selective spatial binding of 8 lectins in the ampullary organs (AOs) of electroreceptors on the rostrum of freshwater paddlefish (Polyodon spathula), by fluorescence imaging and morphometry of frozen sections. A focus was candidate sites of secretion of the glycoprotein gel filling the lumen of AOs. The rostrum of Polyodon is an electrosensory appendage anterior of the head, covered with >50,000 AOs, each homologous with the ampulla of Lorenzini electroreceptors of marine rays and sharks.

Papilla cells may guard the entrance to ampullary organs of Polyodon electroreceptors.

We imaged 'papilla cells' in the skin pores of ampullary organs in electroreceptors on the rostrum of freshwater paddlefish (Polyodon spathula), by lectin labeling and fluorescence stack imaging of frozen sections. >50,000 ampullary organs, each 0.3-0.

The Cortisol and ACTH Response to Dex/CRH Testing in Women With and Without Perimenopausal Depression.

Context: Abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis are frequent accompaniments of depression, and studies have documented the role of stress and stressful life events in the ontogeny of perimenopausal depressions (PMD). Because HPA axis function in women is further modulated both by aging and ovarian steroids, it is possible that a dysregulated HPA axis contributes to the increased risk of PMD.

Objective: We examined HPA axis function in perimenopausal women with and without depression using the combined dexamethasone-corticotropin-releasing hormone (Dex/CRH) test.

Large-Scale Convergence of Receptor Cell Arrays Onto Afferent Terminal Arbors in the Lorenzinian Electroreceptors of .

Certain sensory receptors contain many transducers, converging onto few afferents. Convergence creates star-topology neural networks, of iterative parallel organization, that may yield special functional properties. We quantitated large-scale convergence in electroreceptors on the rostrum of preadult paddlefish, (Acipenseriforme vertebrates), and analyzed the afferent terminal branching underlying the convergence.