Summary
In this study the ultrastructural features of tissue from the posterior hypothalamic area were investigated. Ovariectomized cats which were either treated with sesame oil placebo or with estrogen for varying periods of time were used. The following observations were noted.
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1.
The cat that was treated with placebo one month after ovariectomy showed an increase in the number of dense core (granulated) vesicles within neuronal cytoplasm. This observation was not apparent in the cats which were treated with estrogen one month after ovariectomy.
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2.
In the cat that had been Ovariectomized for two months before treatment with placebo was initiated, axon terminals contained more dense core vesicles than were observed in axonal endings from estrogen-treated cats in the two month ovariectomy group.
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3.
The tissue from cats that were continuously treated with estrogen for one month after ovariectomy displayed dense-core vesicles in both somata and neuropil. It is suggested that the ultrastructural changes observed were dependent on both the time of initiation and the length of estrogen treatment.
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4.
It is concluded that the preliminary observations in this study provide anatomical evidence suggesting that estrogen level in the cat may affect the functional activity of the posterior hypothalamic area.
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This work was supported by a research grant from the National Institute of Neurological Diseases and Stroke (5 R01 NS07557) to Dr. Norma Jean Adamo; by a grant from the National Institutes of Health, NB 05929, to Dr. Donald T. Fraizier, and by a grant from the National Science Foundation, GB 8084, to Dr. Albert Ratner.
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Adamo, N.J., Koenig, J.Q. & Ratner, A. Effects of estrogen on the cat hypothalamus. Z. Zellforsch. 117, 76–86 (1971). https://doi.org/10.1007/BF00331103
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DOI: https://doi.org/10.1007/BF00331103