In order to investigate the estrogen and estrogen receptor β changes after mating behavior of male mandarin vole （Microtus mandarinus）, the radioimmunoassay （RIA） and immunohistochemistry methods were used to inv...In order to investigate the estrogen and estrogen receptor β changes after mating behavior of male mandarin vole （Microtus mandarinus）, the radioimmunoassay （RIA） and immunohistochemistry methods were used to investigate changes of the serum estrogen （E） concentrations, estrogen immunoreactive neurons （E-IRs） and estrogen receptor β immunoreactive neurons （ERβ-IRs） in the relevant brain regions following mating behavior. Fifteen sexually matured male voles were randomly divided into three groups and treated differently： （1） control group： voles were exposed to clean hard-wood shavings （n=5）, （2） exposure group： voles were exposed to the soiled bedding for more than 24h on which estrous females had been placed （n=5）, and （3） mating group： voles were placed with an estrous female for more than 24h （n=5）. The results showed circulating serum E concentrations were significantly higher in the mating group than in the exposure group and the control group, and there were no significant difference between the exposure group and the control group. E-IRs and ERβ-IRs were detected in the following brain regions related to mating behavior： the arcuate nucleus （ARC）, bed nucleus of the stria terminalis （BST）, lateral septal nucleus （LS）, medial amygdaloid nucleus （ME）, medial preoptic area （MPO） and ventromedial hypothalamic nucleus （VMH）. The results showed that there were significantly more E-IRs in the six brain regions in the mating group than in the control group and the exposure group, and there were no significant difference between the exposure group and the control group except for LS. There was no significant difference in ERβ-IRs in the six brain regions among the three groups, and there were some lighter -stained ERβ-IRs in these brain regions. The results suggested that estrogen affect mating activity of male mandarin voles, but ERβ might not play an important role in mating behavior of male mandarin voles. Instead, it might be through other receptors.展开更多
We validated a radioimmunoassay-based method quantifying fecal glucocorticoid metabolites （FGMs） from captive male and female Richardson＇s ground squirrels Urocitellus richardsonii. Blood samples were drawn to expl...We validated a radioimmunoassay-based method quantifying fecal glucocorticoid metabolites （FGMs） from captive male and female Richardson＇s ground squirrels Urocitellus richardsonii. Blood samples were drawn to explore the correlation between plasma cortisol and FGM concentrations. We also injected groups of squirrels with normal saline （CTL; control）, adre- nocorticotropic hormone （ACTH; stimulating adrenal activity）, or dexamethasone （DEX; suppressing adrenal activity）. Potential correlations between stress and behaviour were explored through quantification of fecal pellet production and the intervention necessary to elicit defecation, as well as the behaviour of subjects in the context of handling. Changes in plasma cortisol concen- tration between capture （baseline）, and following handling （stress-induced） were also quantified for free-living squirrels. While glucocorticoid concentrations recovered from feces during our captive-animal study were not well correlated with plasma eortisol concentrations, and uncorrelated with defecation or behaviour, FGM concentrations did reflect the activation of the hypothalamic- pituitary-adrenal （HPA） axis. FGM concentrations increased significantly during initial captivity, but declined to baseline level as individuals acclimated to the novel environment. Injection of subjects with ACTH increased FGMs above baseline, confirming activation of the HPA axis. Plasma cortisol concentrations increased significantly with induced stress, indicating that capture and handling activated the glucocorticoid stress response even among previously handled, free-living subjects. Our findings validate a non-invasive tool that will afford new insight into the physiological processes underlying social, reproductive and antipredator behaviour of Richardson＇s ground squirrels [Current Zoology 60 （5）： 591-601, 2014 ].展开更多
基金Natural Science Foundation of China (30670273)Natural Science Foundation of Shaanxi (2008C269)+1 种基金Science and Technology Plan Project of Xi'an Bureau of Science and Technology (YF07194)Special Science Research Fund for Xi'an University of Arts and Science (KY200520)~~
文摘In order to investigate the estrogen and estrogen receptor β changes after mating behavior of male mandarin vole （Microtus mandarinus）, the radioimmunoassay （RIA） and immunohistochemistry methods were used to investigate changes of the serum estrogen （E） concentrations, estrogen immunoreactive neurons （E-IRs） and estrogen receptor β immunoreactive neurons （ERβ-IRs） in the relevant brain regions following mating behavior. Fifteen sexually matured male voles were randomly divided into three groups and treated differently： （1） control group： voles were exposed to clean hard-wood shavings （n=5）, （2） exposure group： voles were exposed to the soiled bedding for more than 24h on which estrous females had been placed （n=5）, and （3） mating group： voles were placed with an estrous female for more than 24h （n=5）. The results showed circulating serum E concentrations were significantly higher in the mating group than in the exposure group and the control group, and there were no significant difference between the exposure group and the control group. E-IRs and ERβ-IRs were detected in the following brain regions related to mating behavior： the arcuate nucleus （ARC）, bed nucleus of the stria terminalis （BST）, lateral septal nucleus （LS）, medial amygdaloid nucleus （ME）, medial preoptic area （MPO） and ventromedial hypothalamic nucleus （VMH）. The results showed that there were significantly more E-IRs in the six brain regions in the mating group than in the control group and the exposure group, and there were no significant difference between the exposure group and the control group except for LS. There was no significant difference in ERβ-IRs in the six brain regions among the three groups, and there were some lighter -stained ERβ-IRs in these brain regions. The results suggested that estrogen affect mating activity of male mandarin voles, but ERβ might not play an important role in mating behavior of male mandarin voles. Instead, it might be through other receptors.
文摘We validated a radioimmunoassay-based method quantifying fecal glucocorticoid metabolites （FGMs） from captive male and female Richardson＇s ground squirrels Urocitellus richardsonii. Blood samples were drawn to explore the correlation between plasma cortisol and FGM concentrations. We also injected groups of squirrels with normal saline （CTL; control）, adre- nocorticotropic hormone （ACTH; stimulating adrenal activity）, or dexamethasone （DEX; suppressing adrenal activity）. Potential correlations between stress and behaviour were explored through quantification of fecal pellet production and the intervention necessary to elicit defecation, as well as the behaviour of subjects in the context of handling. Changes in plasma cortisol concen- tration between capture （baseline）, and following handling （stress-induced） were also quantified for free-living squirrels. While glucocorticoid concentrations recovered from feces during our captive-animal study were not well correlated with plasma eortisol concentrations, and uncorrelated with defecation or behaviour, FGM concentrations did reflect the activation of the hypothalamic- pituitary-adrenal （HPA） axis. FGM concentrations increased significantly during initial captivity, but declined to baseline level as individuals acclimated to the novel environment. Injection of subjects with ACTH increased FGMs above baseline, confirming activation of the HPA axis. Plasma cortisol concentrations increased significantly with induced stress, indicating that capture and handling activated the glucocorticoid stress response even among previously handled, free-living subjects. Our findings validate a non-invasive tool that will afford new insight into the physiological processes underlying social, reproductive and antipredator behaviour of Richardson＇s ground squirrels [Current Zoology 60 （5）： 591-601, 2014 ].
