Neurobiology of Reproduction in the Female Rat: A Fifty-Year Perspective

ISBN-13: 9783642837999 / Angielski / Miękka / 2011 / 133 str.

John W. Everett

Opis

It has been my privilege and pleasure during the past half century to participate in the unfolding of present-day concepts of the mammalian female reproductive cycles. When the studies recorded here began in the late 1930s it was already established that cyclic ovarian function is governed by gonadotropic secretions from the anterior pituitary gland, the "conductor of the endrocrine orchestra," and that in turn this activity is importantly dependent in some way upon secretion of estro gens and progesterone by the ovaries. Although a role of the nervous system was recognized for the reflex-like induction of ovulation in rabbits and cats and the in duction of pseudopregnancy in rats and mice, and although there was even some evidence of neural participation in ovulation in rats, a major central neural role in the female cycle of most species was not apparent. Gonadotropic fractions of pitui tary extracts having distinct follicle-stimulating and luteinizing activities in test ani mals had been obtained, and these respective effects had been fairly well charac terized. Prolactin was well known for its lactogenic activity, but its luteotropic role in rats and mice had yet to be revealed. The molecular structure of the several estro gens and progesterone was known, and they were readily available as synthetic pro ducts. The broad concept of ovarian-pituitary reciprocity appeared to be an accept able explanation of the female cycle, with the ovary in control through the rhythmic rise and fall in secretion of follicular estrogen."

Spis treści

Vaginal Cytology and Ovarian Status.- Strains of Rats.- Interaction of Environmental Lighting, Age, and Genetic Background Influencing the Estrous Cycle.- Spontaneous Persistent Estrus (SPE).- Influence of Seasonal Variation of Daily Illumination.- Persistent Estrus Induced by Continuous Illumination (LLPE).- Steroid Regulation of the Ovarian Cycle.- Restoration and Maintenance of Ovulatory Cycles by Progesterone Treatment of Persistent-Estrous Rats.- Advancement of Ovulation by Progesterone in Normally Cycling Rats.- Corpora Lutea of Cyclic Rats as Possible Sources of Progesterone.- Induction of Ovulation by Estrogen.- Ovulation Advanced by Estrogen in Cyclic Rats.- Strain Differences in the Ovulation Response to Estrogen.- Timing the Preovulatory Surge of Gonadotropin Secretion.- Blockade of Estrogen-Induced Ovulation.- Blockade of Progesterone-Induced Ovulation.- Blockade of Spontaneous Ovulation.- Pharmacologic Intervention Compared with Hypophysectomy During the ‘Critical Period’.- Effect of the Lighting Rhythm on the ‘Critical Period’.- Circadian Periodicity in Mechanisms Governing the Ovulatory Surge of Gonadotropins.- The Empirical Nature of the ‘Critical Period’.- Central Neural Control of Spontaneous Ovulation: The Rat Model.- Electrochemical Stimulation (ECS).- Electrical Stimulation (ELS).- The Septal-Preoptic-Tuberal System (SPTS) and the Ovulatory LH Surge.- Non-Specific Stimulation of the Tuber by Destructive Lesions.- Dose-Response Relationship of Stimulation to LH Release and Ovulation.- Electrical Stimulation of MPOA versus Basal Tuber.- The Comparative Increments of Circulating LH with Increasing Time of Electrical Stimulation of the Medial Preoptic Area or the Arcuate Nucleus-Median Eminence.- Similarity of LH Surges by MPOA Stimulation in Rats Blocked with Various Drugs.- Stimulation of the Preoptic-Tuberal System During Persistent Estrus.- Overview of the Stimulation Studies.- Pseudopregnancy: Controls for Prolactin Secretion.- Removal of the AP from Direct Influence of the Hypothalamus Favors Secretion of Prolactin.- Pseudopregnancy Induced by Damage to the AP, Stalk-Section, or Damage to the Basal Hypothalamus.- Re-transplantation of AP Grafts from Kidney to Brain.- Delayed Pseudopregnancy: An Approach to Mechanisms I Prolactin Control.- Summary.- References.- Acknowledgments.