The roles of aromatization and steroid receptor activation in the restoration of sociosexual behavior in adult male rats.
Item
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Title
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The roles of aromatization and steroid receptor activation in the restoration of sociosexual behavior in adult male rats.
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Identifier
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AAI9820583
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identifier
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9820583
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Creator
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Vagell, Michael E.
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Contributor
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Adviser: Marilyn McGinnis
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Date
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1998
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Neuroscience | Psychology, Physiological
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Abstract
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This work assessed the role of aromatization and steroid receptor binding in testosterone's restoration of several sociosexual behaviors (such as copulatory behavior, partner preference, 50 kHz vocalizations, and scent marking) in testosterone-treated gonadectomized male rats. Preventing the aromatization of testosterone to estradiol with the aromatase inhibitor fadrozole, completely blocked the restoration of copulatory behavior, but not partner preference. Moreover, treatment with estradiol alone was not sufficient to restore copulatory behavior or partner preference. The two major findings from these experiments were: (1) both androgens and estrogens were necessary for the restoration of copulatory behavior, and (2) aromatization was necessary for the restoration of copulatory behavior, but not partner preference.;Steroid hormones have been traditionally thought to act in the brain by binding to intracellular receptors, which act as ligand-inducible transcription factors. For instance, blocking androgen receptors with the antiandrogen hydroxyflutamide significantly inhibits testosterone's restoration of copulatory behavior, partner preference, 50 kHz ultrasonic vocalizations, and scent marking. This supports the hypothesis that testosterone mediates these sociosexual behaviors by activating cell nuclear androgen receptors. Likewise, if estradiol mediates sociosexual behaviors in male rats through the activation of cell nuclear estrogen receptors, directly blocking estrogen receptors should also inhibit these behaviors. The steroidal antiestrogen, RU 58668 was chosen to test this hypothesis because it was effective in blocking estradiol's effects on both copulatory behavior and brain estrogen receptor binding in female rats. RU 58668 had no effect on the restoration of copulatory behavior or partner preference in testosterone-treated gonadectomized male rats, even though the level of brain cell nuclear estrogen receptor occupation was significantly reduced to the level found in gonadectomized males. However, the restoration of scent marking and 50 kHz vocalizations were impaired by RU 58668. Therefore, the activation of cell nuclear estrogen receptors is necessary for the restoration of some, but not all, sociosexual behaviors. Besides cell nuclear estrogen receptors, there are additional, but unknown, targets of estradiol that play a role in mediating copulatory behavior in adult male rats. This work indicates that the signals from multiple steroid signaling pathways converge in the regulation of sociosexual behaviors.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
