The LHRH neuronal system in female rats: Relation to the medial preoptic nucleus.

Terasawa, Ei; Davis, Gary A.

doi:10.1507/endocrj1954.30.405

Cited by 34 publications

(12 citation statements)

References 29 publications

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“…Both MPN and SCN lesions were effective in in ducing persistent estrus. Findings similar to ours have been reported recently following small MPN lesions [40,44], It is therefore apparent that persistent estrus can be produced by either reduction of LHRH below a critical level for in duction of the preovulatory surge of LH or by destruction of neurons which control the LHRH cells. Neurons within the SCN, the MPN, or both could respond directly or indi rectly to estrogen and progesterone, and act to synchronize the release of LHRH at the proper time to induce an LH surge during the afternoon every 4-5 days.…”

Section: Discussionsupporting

confidence: 90%

Luteinizing Hormone-Releasing Hormone Neuronal System during the Estrous Cycle of the Female Rat:

Rønnekleiv

Kelly²

1986

Neuroendocrinology

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The effects of discrete lesions of the suprachiasmatic and medial preoptic nucleus on luteinizing hormone-releasing hormone (LHRH) neurons of the female rat were examined. The lesions disrupted the estrous cycle and prevented the preovulatory surge of luteinizing hormone and prolactin. Two to three months following the lesions, control and lesioned animals were perfused, the brains were sectioned, and the tissue processed for LHRH immunocytochemistry using the peroxidase antiperoxidase method and a high-titer, conformational antiserum to LHRH. Faintly stained LHRH cells were observed in the preoptic area and the basal hypothalamus at all stages of the estrous cycle. The number of immunoreactive cell bodies varied from a high of 583 cells on proestrus, to a low of 35 cells on estrus (mean ± SEM = 323 ± 59; n = 11). In contrast, the constant estrous animals with lesions showed increased intensity and number of LHRH neurons rostral, lateral and caudal to the lesion. The total number of cells ranged from 625 to 954 cells per animal (mean ± SEM = 784 ± 44; n = 8; p< 0.001 vs. controls). Moreover, all lesioned animals exhibited intense fiber stain in the median eminence region. In conclusion, these data support the hypothesis that persistent estrus is caused by destruction of neurons which directly or indirectly control LHRH neurons.

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Section: Discussionsupporting

confidence: 90%

Luteinizing Hormone-Releasing Hormone Neuronal System during the Estrous Cycle of the Female Rat:

Rønnekleiv

Kelly²

1986

Neuroendocrinology

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“…All of the fe males treated with TP on the 5th day of life failed to show a phasic secretion of LH in response to estrogen and proges terone treatment. This failure to show a positive feedback response to ovarian steroids was also found in animals with discrete lesions of the AVPv [62], Since the lesions did not encoroach upon the GnRH system [41,53], it appears that ablation of the AVPv eliminated a key neural element in volved in the mediation of steroid effects on phasic gonado tropin secretion. The sexually dimorphic dopaminergic cell group in this nucleus, which is at least greatly reduced in both the lesioned and androgen-sterilized animals, may be just such a neural element.…”

Section: Discussionmentioning

confidence: 66%

Influence of Perinatal Androgen on the Sexually Dimorphic Distribution of Tyrosine Hydroxylase-Immunoreactive Cells and Fibers in the Anteroventral Periventricular Nucleus of the Rat

Simerly¹,

Swanson

Handa³

et al. 1985

Neuroendocrinology

178

107

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Recently we reported that the anteroventral periventricular nucleus (AVPv) of the preoptic region contains a dramatic sexual dimorphism in the distribution of tyrosine hydroxylase- (TH-)immunoreactive cells and fibers in the rat. This sexual dimorphism appears to be due to a greater density of dopaminergic fibers, and a larger number of dopaminergic cell bodies, in the AVPv of the female. In the present study we used an indirect immunohistochemical method to evaluate the distribution of TH-immunoreactive cell bodies and fibers, and of dopamine-β-hydroxylase-(DBH-)stained fibers, in the AVPv of female rats that were treated with testosterone propionate (TP) perinatally or postnatally, or were left untreated. All of the postnatally TP-treated animals failed to show a phasic pattern of luteinizing hormone (LH) secretion in response to estrogen and progesterone injections. Both the perinatally and postnatally TP-treated females had polyfollicular ovaries that lacked corpora lutea at the time of gonadectomy. Perinatal TP exposure resulted in what appears to be a complete masculinization of both the number of TH-stained cells and the density of TH-stained fibers in the AVPv. The number of TH-stained cells in the postnatally TP-treated females was also completely masculinized, although the density of TH-stained fibers did not appear to be altered significantly. Gonadectomy resulted in a moderate increase in the density of TH-stained fibers in adult males, and did not significantly affect the fiber density in females, or the number of TH-stained cells in either sex. The distribution of DBH-stained fibers in the AVPv did not appear to be altered in any of the treatment groups. These results suggest that the distribution of dopaminergic fibers in the AVPv may be sensitive to testosterone levels in the adult male, and that although the critical period for the development of this fiber distribution may begin in the prenatal period, the number of dopaminergic cells in the AVPv can be completely sex reversed by a single postnatal dose of TP that appears to correlate with a permanent disruption of the normal pattern of gonadotropin secretion.

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“…1). These neurons are widely distributed in the forebrain of rodents (2)(3)(4)(5)(6)(7)(8) and primates (9)(10)(11). It had been suspected for some time that the GnRH decapeptide is synthesized as part of a larger mol wt precursor (12)(13)(14)(15), and recently, the gene and hypothalamic cDNA encoding the GnRH precursor in human and rat have been described (16).…”

Section: Introductionmentioning

confidence: 99%

Combined Immunohistochemistry for Gonadotropin-Releasing Hormone (GnRH) and Pro-GnRH, andin SituHybridization for GnRH Messenger Ribonucleic Acid in Rat Brain

Rønnekleiv

Naylor

Bond

et al. 1989

Molecular Endocrinology

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Experiments were performed to explore the distribution of neurons containing pro-GnRH and GnRH in the rat brain and to determine the correspondence of immunoreactive peptides and pro-GnRH mRNA. Using avidin-biotin immunohistochemistry on free floating vibratome sections it was found that pro-GnRH- and GnRH-containing cells exhibited a similar distribution within the preoptic area-basal hypothalamus region. Within individual neurons pro-GnRH was primarily detected in the cell soma and proximal fibers, whereas the decapeptide was present in cells, fibers, and nerve terminals. Combined avidin-biotin immunohistochemistry for GnRH or pro-GnRH peptides and in situ hybridization for pro-GnRH mRNA using a cRNA probe revealed that the peptides and mRNA could be detected in the same cells. In both male and female rats pro-GnRH mRNA was localized primarily in GnRH-containing cells; however, not all immunoreactive GnRH neurons contained detectable levels of pro-GnRH mRNA, and not all neurons containing pro-GnRH mRNA contained GnRH peptides. In proestrous females a close correlation existed between the total number of neurons containing GnRH and those containing pro-GnRH mRNA (r = 0.84-0.9), while in intact male rats the correlation was not as high (r = 0.56). These results document the distribution of pro-GnRH and GnRH in the rat preoptic area-basal hypothalamus and describe the extent of colocalization of GnRH peptide and pro-GnRH mRNA in proestrous females and intact male rats. Further work will determine how each of the molecular components is regulated during different reproductive states.

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The LHRH neuronal system in female rats: Relation to the medial preoptic nucleus.

Cited by 34 publications

References 29 publications

Luteinizing Hormone-Releasing Hormone Neuronal System during the Estrous Cycle of the Female Rat:

Luteinizing Hormone-Releasing Hormone Neuronal System during the Estrous Cycle of the Female Rat:

Influence of Perinatal Androgen on the Sexually Dimorphic Distribution of Tyrosine Hydroxylase-Immunoreactive Cells and Fibers in the Anteroventral Periventricular Nucleus of the Rat

Combined Immunohistochemistry for Gonadotropin-Releasing Hormone (GnRH) and Pro-GnRH, andin SituHybridization for GnRH Messenger Ribonucleic Acid in Rat Brain

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