• The Korean Journal of Zoology
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• v.37 no.3
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• pp.304-310
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• 1994

Using in situ hybridization, we have mapped the anatomical localization of perikarya containing myNA that codes for sonadotropin releasing hormone (GnRH) in the brains of female frogs, R. dybowskii. DNA olisomers, with sequences complementary to the GnRH portion of pro-GnRH myNA sequence, were synthesized and hybridized to paraformaldehvde-fixed, sagittal sections of the whole brain stem. The distribution of the GnRH mRNA containing cell bodies was similar to that described for GnRH peptide by immunohistochemistrv. That is, cells containing GnRH mRNA were observed in the medial septal area, anterior preoptic area, ventromedial hvpothalamus and infundibular regions. However, another cell groups which contains GnRH mRNAs were also detected by in situ hybridization in the bed nucleus of hippocampal commissure, preoptic area, nucleus infundibularis dorsalis, mesencephalic nuclei and intermediolateral cell column of spinal cord areas. These results demonstrate the feasibility of using in situ hybridization as a strategy to study the distribution of GnRH neurons and the detection of GnRH gene expression in the vertebrates.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.215-222
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• 1999

Nonylphenol (NP) is a widespread environmental pollutant that has been shown to exert both toxic and estrogenic effects on mammalian cells. As the effects of NP on the reproductive system of adult male vertebrates are virtually unknown, we investigated not only the changes of reproductive hormone secretion in serum after chronic exposure to NP but also, in order to identify the site of its action, the reproductive hormone secretion in serum 48 hours after microinfusion of NP within hypothalamic preoptic area (POA). In the chronic exposure, the luteinizing hormone (LH), follicle stimulating hormone (FSH), and testosterone in serum were decreased but prolactin (PRL) concentrations were increased. The LH, FSH, and testosterone in serum were decreased through the direct infusion of NP into POA, while there was no difference in mean serum prolactin between NP and control groups. These observations suggest that NP as endocrine disruptor has modulatory effects on hypothalamo-pituitary-gonadal axis and that the site of action of NP could be hypothalamic POA.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.6
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• pp.439-444
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• 2000

Tricyclic antidepressant clomipramine or selective serotonin reuptake inhibitors (SSRIs) have been commonly used for the treatment of premature ejaculation. In the present study, we analyzed the concentrations of serotonin and 5-hydroxyindoleacetic acid (5-HIAA) in the medial preoptic area (MPOA) of the hypothalamus by awakening animal microdialysis following administration of clomipramine and various SSRIs. We then compared the serotonin metabolism and clinical effects of clomipramine and SSRIs on premature ejaculation. Basal extracellular serotonin level in the MPOA was higher than other brain regions and it was significantly increased by clomipramine and the SSRIs. The rank order of the concentration of serotonin at the MPOA was clomipramine, sertraline, paroxetine and fluoxetine and the concentrations of 5-HIAA was vice versa. The changes in serotonin concentration at the MPOA appeared closely associated with the clinical effects of these drugs on premature ejaculation. These results suggest that the serotonergic neuronal activity in the MPOA may have an selective inhibitory influence on ejaculation, and the effects of clomipramine and SSRIs on erectile function are mainly mediated by MPOA of the hypothalamus.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.83.1-83.1
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• 2003

The heterotrimeric G protein subunits (G ) are region-specifically expressed in brain such as hypothalamus and pituitary gland in abundant, suggesting that is may be associated with “stress-axis”. This study was designed to examine the effect of stress on the region-specific expression of various G subunits in rat brain. The localization of mRNAs encoding seven of G and striking region-specific patterns of expression were observed in 12 different regions of both non-stressed and stressed rat brain; (1) frontal cortex area, (2) cerebral cortex area, (3) striatum, (4) hippocampus area, (5) thalamus, (6) brain stem, (7) cerebellum area, (8) hypothalamus, (9) septum, (10) amygdala, (11) preoptic area, and (12) pituitary gland. (omitted)

• Toxicological Research
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• v.17
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• pp.313-317
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• 2001

The Ministry of Health and Welfare of Japan has set up six research groups concerning the endocrine disrupting chemicals. One of these projects was "A study on development of testing methodology for health effects due to exposure of environmental endocrine disruptors". In this paper, three topics are described. In OECD collaboration for pre-validation of uterotrophic assay, the most sensitive response to ethnyl estradiol was noted in the ovarectomized rats treated subcutaneously for 7 days. Secondly, it was suggested that changes of the serum $\alpha_{2u}$-globulin level may be a sensitive parameter for detecting the estrogenic activities of chemicals. Finally, development of the sexually dimorphic nucleus of preoptic area in the brain oj male rats was inhibited by the treatment with estrogenic chemicals, and their masculine behaviors and reproductive abilities were impaired after sexual maturation. In conclusion, these parameters are considered to be sensitive endpoints for testing estrogenic chemicals.chemicals.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.479-487
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• 1997

The present study was carried out to localize the central nuclei innervating the rat colon using pseudorabies virus-Bartha strain which has been known as a very useful neurotracer. The results were as follows. The central nuclei innervating the proximal colon were premotor area, subfornical organ, preoptic area in telencephalon, and paraventricular nucleus, bed nucleus of stria terminalis, retrochiasmatic area in the diencephalon, and periaqueductal gray, Edinger-Westphal nucleus, tegmental nucleus in the mesencephalon, and parabrachial nucleus, locus ceruleus, A5 area, $K{\ddot{o}}lliker$-Fuse nucleus, magnocellular reticular nucleus in the metencephalon, and nucleus tractus solitarius, A1 noradrenergic cell group, dorsal motor nucleus of vagus nerve, nucleus ambiguus, area postrema in the myelencephalon. In the spinal cord, the thoracic division had some nuclei innervating the proximal colon. The nuclei innervating the distal colon were paraventricular nucleus of the diencephalon, Edinger-Westphal nucleus of midbrain, and parabrachial nucleus, locus ceruleus, A5 area, $K{\ddot{o}}lliker$-Fuse nucleus, magnocellular reticular nucleus of the metencephalon, and nucleus tractus solitarius, dorsal motor nucleus of vagus nerve, nucleus ambiguus, area postrema in the myelencephalon. In the spinal cord, thoracic, lumbar and sacral division innervated the distal colon.

• Journal of Acupuncture Research
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• v.20 no.6
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• pp.89-102
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• 2003

Objective: The expression of CRF(corticotropin releasing factor), CRF-R(receptor) and CRF-BP(binding protein) in CNS neurons projecting to the stomach and ST36 using the pseudorabies virus in the rat was investigated. Methods: After survival times of 5 days following injection of PRV-Ba-Gal, The thirty rats were perfused, and their brain were frozen sectioned($30{\mu}m$). These sections were stained by PRV-Ba-Gal histochemical staining method and(or) CRF, CRF-R and CRF-BP immunohistochemical method. The common expressed areas of the brain projecting to the stomach and zusanli(ST36) following injection of PRV-Ba-Gal were observed with light microscope. Results: 1) The dense accumulation of CRF-immunoreactive terminals is seen in the area postrema, n. tractus solitarius, external zone of the median eminence, with some immunoreactive CRF also present in the internal zone. 2) Aggregates of CRF-R immunoreactive perikarya are found in area postrema, n. tractus solitarius, lateral reticular n., gigantocellular reticular n., locus coeruleues, paraventricular n. of hypothalamus, median eminence, preoptic n., arcuate n. and hind limb area of cerebral cortex. 3) Aggregates of CRF-BP immunoreactive perikarya are found in area postrema, n. tractus solitarius, lateral reticular nucleus, gigantocellular reticular n., locus coeruleues, paraventricular n. of hypothalamus, median eminence and arcuate n.. Conclusions : These results suggest that PRV-Ba-Gal labeled areas projecting to stomach and ST36 may be related to the central autonomic pathways. A part of CNS neurons projecting to the stomach and ST36 were related to expression of CRF, CRF-R and CRF-BP related to the stress in central autonomic center.

• Animal cells and systems
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• v.3 no.1
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• pp.1-7
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• 1999

Gonadotropin-releasing hormone (GnRH) was originally isolated as a hypothalamic peptide that regulates reproduction by stimulating the release of gonadotropins. Using comparative animal models has led to the discovery that GnRH has a more ancient evolutionary origin. Durinq evolution GnRH peptide underwent gene duplication and structural changes to give rise to multiple molecular forms of GnRHs. Mammalian GnRH initially considered to be the sole molecular form, is now grouped as a family of peptides along with GnRH variants determined from representatives in all classes of vertebrates. Vertebrate species including primates and humanshave more than one GnRH variant in individual brains; a unique GnRH form in the forebrain and chicken IIGnRH in the midbrain. Furthermore, several species of bony fish have three molecular variants of GnRH: salmon GnRH sea-bream GnRH and chicken II GnRH. Also, it has been shown that in addition to the olfactory placodes and the midbrain, there is a third embryonic source of GnRH neurons from the basal diencephalon in birds and fish, which might be true for other vertebrates. Therefore, comparative animal models like fish with discrete sites of expression of three molecular variants of GnRH in individual brains, could provide insight into novel functions of GnRH variants, conservation of gene regulation, and mechanisms governing reproduction in vertebrates.

• Investigative Magnetic Resonance Imaging
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• v.26 no.2
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• pp.96-103
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• 2022

Purpose: The survival of organisms critically depends on avoidance responses to life-threatening stimuli. Information about dangerous situations needs to be remembered to produce defensive behavior. To investigate underlying brain regions to process information of danger, manganese-enhanced MRI (MEMRI) was used in olfactory fear-conditioned rats. Materials and Methods: Fear conditioning was conducted in male Sprague-Dawley rats. The animals received nasal injections of manganese chloride solution to monitor brain activation for olfactory information processing. Twenty-four hours after manganese injection, rats were exposed to electric foot shocks with odor cue for one hour. Control rats were exposed to the same odor cue without foot shocks. Forty-eight hours after the conditioning, rats were anesthetized and their brains were scanned with 9.4T MRI. Acquired images were processed and statistical analyses were performed using AFNI. Results: Manganese injection enhanced brain areas involved in olfactory information pathways in T1 weighted images. Rats that received foot shocks showed higher brain activation in the central nucleus of the amygdala, septum, primary motor cortex, and preoptic area. In contrast, control rats displayed greater signals in the orbital cortex and nucleus accumbens. Conclusion: Nasal delivery of manganese solution enhanced olfactory signal pathways in rats. Odor cue paired with foot shocks activated amygdala, the central brain region in fear, and related brain circuits. Use of MEMRI in fear conditioning provides a reliable monitoring technique of brain activation for fear learning.

• Animal cells and systems
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• v.3 no.3
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• pp.311-317
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• 1999

Prolactin (PRL) was reported to be locally synthesized in many brain areas including the hypothalamus, thalamus (TH) and hippocampus (HIP). In the pituitary lactotrophs, PRL synthesis is dependent upon a pituitary-specific transcription factor, Pit-1. In the present study, we attempted to identify Pit-1 or Pit-1-like protein in brain areas known as the synthetic sites of PRL. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis showed the same Pit-1 transcripts in brain areas such as the medial basal hypothalamus (MBH), preoptic area (POA), TH, and HIP with the Pit-1 transcripts in the anterior pituitary (AP). Electrophoretic mobility shift assay (EMSA) was run with nuclear protein extracts from brain tissues using a double strand oligomer probe containing a putative Pit-1 binding domain. Shifted bands were found in EMSA results with nuclear proteins from MBH, POA, TH and HIP. Specific binding of the Pit-1-like protein was further confirmed by competition with an unlabeled cold probe. Antisense Pit-1 oligodeoxynucleotide (Pit-1 ODN), which was designed to bind to the Pit-1 translation initiation site and block Pit-1 biosynthesis, was used to test Pit-1 dependent brain PRL transcription. Two nmol of Pit-1 ODN was introduced into the lateral ventricle of a 60-day old male rat brain. RNA blot hybridization and in situ hybridization indicated a decrease of PRL mRNA signals by the treatment of Pit-1 ODN. Taken together, the present study suggests that Pit-1 may play an important role in the transcriptional regulation of local PRL synthesis in the brain.