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1
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Effects of growth hormone on neuroendocrine function

100%
Bartke A., Chandrashekar V., Steger R. W.
Acta Neurobiologiae Experimentalis
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1996
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vol. 56
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issue 3
833-842
EN
Although the role og growth hormone (GH) in the control of reproductive functions is not well understood, there is considerable evidence that the states of both GH deficiency and GH excess are typically associated with reproductive deficits.To identify the possible involvement of functinal alternations in the hypothalmic-pituitary system in producing these deficits, we are studying neuroendocrine function related to reproduction in transgenic animals overexpressing GH, in animals with congenital GH deficiency, and in animals with selective immunonoutralization of GH.The results indicate that GH acts on the hypothalmus to alter dopaminergic and noradrenergic control of prolactin and gonadotrophin release.Life-long elevation of GH levels outside the physiological range disrupts feedback control of luteininzing hormone (LH) relaese by gonadal steroids.Plasma LH and follicle-stimulating hormone (FSH) levels and feedback control of LH release are also abnormal in GH-deficient animals indicating that physiologival levels of endogenous GH are normally involved in the control of gonadotropin release.Differences between the effects of bovine vs.human GH in transgenic moce and differential effects of GH mechanisms involved in the actions of HG on the hypothalmic-pituitary system.
2

Expression of Npc1 in Glial Cells Corrects Sterility in Npc1-/- mice

100%
Donohue C., Marion S., Erickson R. P.
Journal of Applied Genetics
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2009
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vol. 50
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issue 4
385-390
EN
Niemann-Pick type C1 (NPC) disease is an autosomal recessive neurodegenerative disorder. One feature of the mouse model of NPC1 is it's infertility. We have made transgenic mice which express the Npc1 protein exclusively in fibrillary astrocytes, using the glial fibrillary acidic protein (GFAP) promoter. This selective expression of Npc1 corrects sterility in GFAP-Npc1E, Npc1-/- mice. Counts of acidophils in the pituitary of GFAP-Npc1E, Npc1-/- mice, as compared to Npc1-/- mice, and measurements of dopamine D2 receptor (DRD2) mRNA in the pituitary, suggest mechanisms for fertility enhancement. We conclude that the correction of sterility in GFAP-Npc1E, Npc1-/- mice is a result of restoring hypothalamic control of the pituitary.
3
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The spontaneous theta rhythm recorded from the hypocalmus posterior in the cat in vivo

100%
Grabowski R., Blaszczyk M., Eckersdorf B., Golebiewski H., Konopacki J.
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EN
Rhythmical slow activity (theta) was mapped in the hypothalamic regionin freely moving cats. We recorded well synchronized and high amplitude theta rhythm in the medial part of hypothalamus posterior area. The EEG recordings made from lateral part of this hypothalamic region contained only irregular activity. These findings support earlier observations concerning the topography of hippocampal formation desynchrony and synchrony system. The observations of the present study also suggest that the hypothalamus posterior area is actively involved in the mechanisms responsible for generating theta oscillations in the cats.
4
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Anatomical correlates of the lateral hypothalamic influence on waking-sleep relationship in the rat

88%
Orzel-Gryglewska J., Jurkowlaniec E., Nowacka A., Tokarski J., Trojnia W.
Acta Neurobiologiae Experimentalis
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2000
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vol. 60
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issue 3
309-322
EN
Restricted electrolytic lesions of the lateral hypothalamus (LH) evoke sleeplessness in the rat. The present study was aimed to analyze a possible anatomical substrate of the LH hyposomnia within the hypothalamus. In a group of electrolytically lesioned LH rats the intensity of sleep disturbances, assessed on the basis of EEG records from the neocortex and the hippocampus, was confronted with the localization and the extent of destruction of the LH area and with the topography of known fiber systems of the medial forebrain bundle (MFB). In separate experiments the effects of the destruction of LH cell bodies by means of bilateral ibotenic acid (IBO) injections and inhibition of LH neuronal elements by bilateral muscimol (MUSC) administration were also tested. It was found that pronounced hyposomnia follows electrolytic but not IBO lesions of the LH/MFB area. The effective LH damage might have been localized at every level of its antero-posterior axis, from the preoptic area up to the posterior hypothalamus, suggesting involvement of fiber system(s) rather than a localized group of neuronal pericaria. The most effective lesions transsected projections descending from the preoptic/anterior hypothalamic area, olfactory structures, ventral striatum and the central amygdaloid nucleus as well as fibers connecting LH with the brainstem reticular formation, many of them using GABA as a neurotransmitter. Bilateral MUSC injections caused a dose-dependent, bicuculline-reversible, increase in waking time, most pronounced at a dose of 50 ng, which ressembled the effect of the electrolytic lesion. These results indicate that LH hyposomnia is not attributable to the damage to the intrahypothalamic neurons and suggest the participation of GABA-ergic transmission in LH in waking-sleep regulation.
5
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Neuropeptide Y (NPY) and its mRNA in discrete brain areas after subchronic administration of neuroleptics

75%
Herman Z. S.
Acta Neurobiologiae Experimentalis
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1996
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vol. 56
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issue 1
55-61
EN
Classical (chlorpromazine, haloperidol) and atypical (sulpiride and clozapine) neuroleptics applied for a period of 2 weeks diminished neuropeptide Y (NPY) levels in nucleus accumbens, but not in striatum. These changes were correlated with NPY mRNA level. However, the effect of these neuroleptics on the level of NPY in hypothalamus was different. It is suggested that changes in NPY levels caused by neuroleptics are mediated by dopaminergic D1/D2 receptors.
6
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Effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on cyclic AMP formation in the duck and goose brain

75%
Nowak J. Z., Kuba K., Zawilska J. B.
Acta Neurobiologiae Experimentalis
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2000
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vol. 60
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issue 2
209-214
EN
Two molecular forms of pituitary adenylate cyclase-activating polypeptide (PACAP), i.e., PACAP27 and PACAP38 (0.0001-1 muM), as well as vasoactive intestinal polypeptide (VIP; 0.1-3 muM), have been studied for their effects on cyclic AMP formation in the hypothalamus and cerebral cortex of duck and goose. All three peptides concentration-dependently stimulated cyclic AMP production in the tested brain regions of 2-3-weeks-old (young) ducks, with VIP showing at least one order of magnitude weaker activity than PACAP. This characteristics suggests the existence in the duck's brain of adenylyl cyclase-linked PAC1 receptors. Both forms of PACAP also stimulated the nucleotide formation in the cerebral cortex and hypothalamus of 5-6-months-old (adult) ducks or geese grown under natural environment. The peptides-evoked effects in adult and young ducks were comparable, and clearly greater than those found in adult geese. The present data extend our recent observations made on chicks, and suggest PACAP to be a potent stimulator of the cyclic AMP generation in the avian central nervous system.
7
Content available remote

Stress and nutritional influences on GnRH and somatostatin neuronal system in the ewe

75%
Polkowska J.
Acta Neurobiologiae Experimentalis
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1996
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vol. 56
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issue 3
797-806
EN
The efect of stressful stimulation and protein malnutration on the gonadotrophic and somatotrophic axis of sheep is discussed with special references to the relatioship between these stimuli and the GnRH and somatostatin neuronal system in the hypothalmus.Generally, long-term stimulation and chronic underfeeding reduce gonadal functions in the sheep.There is evidence for the GnRH-dependent pathway for the mechanism of these phenomena in femle sheep.GnRh neurons respond to long-term stress in diminishing of neuropeptide release from the nerve terminals due to the depression of its axonal transport.Chronic restriction of dietary proteins in lambs reduces the plasma LH concentration but does not impair the development of GnRH neurons nor the synthesis and processing of GnRH.It is suggested that malnutrition delays the first ovulation probably due to the neural mechanism responsible for the preovulatory GnRH/LH output.Stress has rather unclear effect on growth hormone (GH) secretion in the sheep.Prolonged, but not short stressful stimulation provokes the rapid release of somatostatin, which is sustained during long-term stimulation.These results suggest that effect of stress on somatotrophic axis depends on the period of stressful stimulation.VChronic malnutrition enhances secretion of GH by an increse in amplitude of GH pulses and reduces the secretory activity of somatostatin neurons.It is postulated that nutrients can influence GH secretion in the sheep by mechanism dependent on the hypothalmic somatostatin.
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