Using extracellular recording we studied changes in the reactivity of rat hippocampal slices to an agonist of the 5-HT(7) receptor, 5-carboxamidotryptamine (5-CT; 0.025-1 microM), induced by an earlier treatment of animals with corticosterone. Spontaneous bursting activity was recorded in ex vivo slices incubated in the presence of 2-[4-(2-methoxyphenyl)-1piperazinyl]ethyl]-N-2-pyridinylcyclohe...

The objective of this study was to investigate the effects of dietary corticosterone on egg quality. For 2 weeks hens received either control or experimental diet containing corticosterone at 30 mg/kg diet. Feed intake and egg production were monitored daily, and body weight measured weekly. Egg weights and egg quality were measured daily. Corticosterone treatment resulted in a remarkable incre...

Activation of glucocorticoid receptor signaling in the stress response to traumatic events has been implicated in the pathogenesis of stress-associated psychiatric disorders such as post-traumatic stress disorder (PTSD). Elevated startle response and hyperarousal are hallmarks of PTSD, and are generally considered to evince fear (DSM V). To further examine the efficacy of corticosterone in trea...

The affinity of corticosterone to organic cation transporters (OCTs) is subtype- and species-dependent. For example, the IC50 values for corticosterone inhibition of cation uptake by transporters rOCT1 and rOCT2 are approximately 150 and approximately 4 microM, respectively. By introducing domains and amino acids from rOCT2 into rOCT1, we found that the exchange of three amino acids in the pres...

Jugular catheters were inserted in nine male rats under general isofluorane anesthesia and the catheters were connected to a commercially available computerized blood sampling device (Accusampler). Blood samples (150 microl) were collected every 4 h during the first 24 h after surgery and every 12 h during the following 72 h until 94 h after surgery, when the animals were killed. All fecal pell...

Prolonged or frequent secretion of adrenal glucocorticoids in response to aversive stimuli can negatively impact reproduction. Because female southern white rhinoceros (Ceratotherium simum simum) reproduce poorly in captivity, we compared fecal corticosterone metabolite concentrations among parous, nulliparous, and adolescent females and examined social and physical aspects of the captive envir...

Corticosterone levels in blood may be used as a marker of stress in rodents, provided that the blood sampling procedure itself is non-stressful. Automated blood sampling equipment (Accusampler) allows blood sampling without any interference with the animal and might be useful as a tool for an on-line measurement of stress markers in blood. However, the impact of the blood sampling itself on the...

While evidence is accumulating that stress-induced glucocorticoid responses help organisms to quickly adjust their physiology and behaviour to life-threatening environmental perturbations, the function and the ecological factors inducing variation in baseline glucocorticoid levels remain poorly understood. In this study we investigated the effects of brood size by experimentally manipulating th...

Captive European starlings (Sturnus vulgaris) were exposed to the stress of handling and restraint while corticosterone, glucose, and triglyceride concentrations were monitored in blood plasma. In saline-injected controls, basal samples were taken within 3 min of disturbance with subsequent samples taken at 40, 70, and 150 min. This was repeated at two times during the daily cycle (day and nigh...

In amphibians, large changes in tissue corticosterone content (caused by treatment with large doses of hormone) alter tadpole growth and development, but the effects of smaller changes on growth, development, behavior, and morphology are unknown. In the current study, we exposed pre-metamorphic Rana pipiens tadpoles to moderate doses (62 and 125 nM) of exogenous corticosterone by adding it to t...