Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains viii, 71 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 61-70).

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 161-197). Also available in print.

The ability of an animal to respond and adapt to stimuli is necessary for its survival and involves plasticity and coordination of multiple levels of biological organization, including behavior, tissue organization, hormones, and gene expression. Each of these levels of response is complex, and none of them responds to stimuli in isolation. Thus, to understand how each system responds, it is necessary to consider its role in the context of the entire organism. Here, I have used the African cichlid fish Astatotilapia burtoni and its extraordinary phenotypic plasticity to investigate how animals respond to a change in social status from subordinate to dominant and attempted to integrate these multiple levels of biological response, as well as the roles of several candidate neuromodulators,. First, I have described how male A. burtoni become more aggressive and reproductive during their transition to dominance as well as increasing circulating levels of testosterone and estradiol and the histological organization of their testes. I then mapped the distribution of expression of two behaviorally relevant neuropeptides, arginine vasotocin and isotocin, and their respective receptors, throughout the A. burtoni brain, and found that they were highly expressed in several brain areas important for social behavior and decision-making. I then investigated the role of arginine vasotocin in social status and behavior via pharmacological manipulation and qPCR, showing the importance of arginine vasotocin in controlling the transition to dominance. Lastly, I investigated the role of aromatase, testosterone, and estradiol in male A. burtoni, both in stable dominant males and in males as they transition to dominance, using pharmacological manipulation and quantitative radioactive in situ hybridization, illustrating that estradiol synthesis during dominance is dependent on aromatase activity and necessary for aggressive behavior. / text

Pastaraisiais metais vyksta labai daug elgsenos endokrininės kontrolės tyrimų. Mūsų darbe mes tyrėme galimą estrogenų vaidmenį vištų patelių lytinės elgsenos difirenciacijai. Eksperimentiniai gyvūnai 8 embrioninio vystymosi dieną buvo aveikti aromatazės inhibitoriumi, fadrozoliu, tokiu būdu blokuojant estradiolio gamybą. Kontroliniams gyvūnams buvo suleistas fizioliginis tirpalas. Suaugusių vištų elgsena buvo stebima dvejuose skirtinguose lytinės elgsenos testuose: su suaugusiu intaktiniu (nepaveiktu) gaidžiu ir su intaktine (kontroline) višta. Testuojant su gaidžiu fadrozoliu paveiktos vištos rodė mažesnį pasiruošimą kopuliuoti su gaidžiu, turėjo polinkį dominuoti ir vengti gaidį. Testuojant su kontroline višta, eksperimentiniai paukščiai rodė vyrišką elgseną - sparno rėžimą, bandymus kopuliuoti ir giedojimą. Kelios fadrozoliu paveiktos vištos rodė pilną kopuliacinės elgsenos seką, tame tarpe kloakų kontakto judesius. Mūsų tyrimai palaiko hipotezę, kad estrogenai yra pagrindinis faktorius, lemiantis naminių vištų lytinės elgsenos diferenciaciją. / In recent years much scientific reseach is devoted to the endocrine control of behaviour. In our work we studied the possible role of estrogens in differentiation of sexual behaviour in female chickens. Eksperimental animals were treated on day 8 of embrionic development with an aromataze inhibitor, fadrozole, thus blocking the oestradiol production. Control animals received injections of vehicle (saline). In adulthood behaviour of hens was observed in two different sexual behaviour tests: with mature non-treated (intact) cocks and with non-treated (control) hens. When tested with a cock, fadrozole-treated hens showed reduced readiness to copulate with a cock, tended to dominate and to avoid a cock. When tested with a control hen, experimental birds displayed male-type behaviour – waltzing, mount attempts and crowing,. Some of fadrozole-treated hens showed a full sequence of copulatory behaviour, including cloacal contact movement. Our study supports the hypothesis that oestrogens play a major role in differentiation of sexual behaviour in the domestic chickens.

The purpose of this study was to characterize the endocrine stress response of zebrafish (Danio rerio) and to test if this response is modified by sex or the major sex steroids 17β-estradiol (E2) and 11-ketotestosterone (11KT). A standardized stress of having zebrafish swim in a beaker of stirring water resulted in rapid and transient changes in whole-body cortisol. While the cortisol response of males and females were comparable, exposure to E2 (100 ng/L) for 48 h inhibited the cortisol response of males and exposure to 11KT (100ng/L) for 48 h stimulated the cortisol response of females. The inhibitory actions of E2 were mediated in part by decreases in corticotropin releasing factor (crf) expression and decreases in the synthesis of cortisol by interrenal tissue. This research adds to the increasing knowledge of zebrafish physiology and will be useful for future studies concerning the endocrine stress response in fish.

Background: Serum estradiol levels decline after menopause and the effect on mental health-related quality of life (MHR-QOL) is unclear. Objective: To determine if there is an association between endogenous serum estradiol levels and MHR-QOL in healthy postmenopausal women. Methods: This cross-sectional study used baseline Canadian data from the Mammary Prevention.3 trial. Serum estradiol was measured with liquid chromatography-tandem mass spectrometry. Outcomes for MHR-QOL were the Medical Outcomes 36-Item Short Form Health Survey (SF-36) Mental Health Inventory-5 (MHI-5), Mental Component Summary (MCS), and the Menopause-Specific Quality of Life Questionnaire (MENQOL)-psychosocial domain. Results: There were no statistically significant associations between estradiol levels and MHR-QOL in univariate analyses (n=455). Multivariable linear regression predicted statistically significant differences in MCS (R2=0.10, P=0.03) and MENQOL-psychosocial domain (R2=0.10, P=0.04), however estradiol was not a significant predictor. Conclusions: This study did not find a statistically significant association between endogenous serum estradiol levels and MHR-QOL in healthy postmenopausal women.

Background: Serum estradiol levels decline after menopause and the effect on mental health-related quality of life (MHR-QOL) is unclear. Objective: To determine if there is an association between endogenous serum estradiol levels and MHR-QOL in healthy postmenopausal women. Methods: This cross-sectional study used baseline Canadian data from the Mammary Prevention.3 trial. Serum estradiol was measured with liquid chromatography-tandem mass spectrometry. Outcomes for MHR-QOL were the Medical Outcomes 36-Item Short Form Health Survey (SF-36) Mental Health Inventory-5 (MHI-5), Mental Component Summary (MCS), and the Menopause-Specific Quality of Life Questionnaire (MENQOL)-psychosocial domain. Results: There were no statistically significant associations between estradiol levels and MHR-QOL in univariate analyses (n=455). Multivariable linear regression predicted statistically significant differences in MCS (R2=0.10, P=0.03) and MENQOL-psychosocial domain (R2=0.10, P=0.04), however estradiol was not a significant predictor. Conclusions: This study did not find a statistically significant association between endogenous serum estradiol levels and MHR-QOL in healthy postmenopausal women.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2005.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2006. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 103-110). Also available on the Internet.