Abstract:
:A consistent group of gonadotropin-releasing hormone (GnRH) cell bodies occurs in the ventral hypothalamic tract at the infundibular lip (IL), just below the arcuate nucleus (ARC), at the site of the so-called GnRH 'pulse generator'. Immunocytochemical studies were performed to examine contacts between these GnRH neurons and nearby opioid peptide (OP) neurons in the ARC. Vibratome sections of the medial basal hypothalamus were obtained from colchicine-treated, perfusion-fixed juvenile female rhesus macaques. They were sequentially immunostained for GnRH using the peroxidase antiperoxidase (PAP) technique and for adrenocorticotropic hormone (to identify OP neurons) using colloidal gold. The PAP and colloidal gold markers could be clearly differentiated at both the light and electron microscopic levels. OP+ and GnRH+ neuronal cell bodies occurred close together in the ARC-IL region, sometimes within the same electron microscope grid square. At the electron microscopic level, OP+ axons formed symmetrical synapses with GnRH+ somata and proximal axons, suggesting a pronounced inhibitory influence on GnRH neuronal activity. Examples of OP+/GnRH+ axodendritic and dendrodendritic contacts were also observed. Furthermore, symmetrical synapses between GnRH+ axons and GnRH+ perikarya or dendrites were occasionally present. The data obtained here clearly indicate that direct OP inhibition of GnRH 'pulse generator' neurons occurs at the ARC-IL in juvenile primates. It is suggested that these OP neurons help mediate steroid-negative feedback at the hypothalamic level. Furthermore, it is suggested that OP/GnRH and GnRH/GnRH inhibitory contacts may play a role in maturation and control of reproductive function.
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Thind KK,Goldsmith PCdoi
10.1159/000124914subject
Has Abstractpub_date
1988-03-01 00:00:00pages
203-16issue
3eissn
0028-3835issn
1423-0194journal_volume
47pub_type
杂志文章abstract::Although previously considered rare, recent epidemiological studies have revealed that the incidence (3.6/100,000) and prevalence (35/100,000) of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has increased over the past few decades. Despite the progress in the understanding of GEP-NET molecular biology, ther...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000362339
更新日期:2014-01-01 00:00:00
abstract:BACKGROUND:The reviewing and assessment of epidemiological characteristics of neuroendocrine tumours (NETs) remains a challenge. Despite the fact that it is an uncommon family of neoplasms, several worldwide series have revealed an increasing incidence of this rare condition. However, the data are difficult to compare ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000441897
更新日期:2017-01-01 00:00:00
abstract::Introduction Autophagic cell death in cancer cells can be mediated by inhibition of deacetylases. Although extensive studies have focused on the autophagic process in cancer, little is known about the role of autophagy in degrading cytosolic and nuclear components of pancreatic neuroendocrine neoplastic (pNEN) cells l...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000512567
更新日期:2020-10-27 00:00:00
abstract::We have previously reported that luteinizing hormone releasing hormone (LH-RH) levels in the medial basal hypothalamus (MBH) of adult male rats castrated for 2 weeks can be raised by testosterone (T) or estradiol (E2) treatment for 3-4 days. The present study was undertaken to determine the time after castration when ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124188
更新日期:1985-09-01 00:00:00
abstract:BACKGROUND/AIM:The mode of action of the somatostatin analog octreotide on neuro-endocrine tumour proliferation is largely unknown. Overexpression of the proto-oncogene Akt/PKB (protein kinase B) has been demonstrated in certain neuro-endocrine tumours: Akt activates downstream proteins including mTOR and p70S6K, which...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000111501
更新日期:2008-01-01 00:00:00
abstract::In situ hybridization was used to examine the effects of amygdala kindling on the expression of mRNAs for mineralocorticoid receptors (MR) and glucocorticoid receptors (GR) in the rat hippocampus. Kindling increased MR mRNA levels in the dentate gyrus of the hippocampus 4 h after the last seizure, and these levels rem...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126691
更新日期:1994-05-01 00:00:00
abstract::Chronic exposure to Delta(9)-tetrahydrocannabinol (Delta(9)-THC) increases corticotropin-releasing hormone (CRH) and proopiomelanocortin (POMC) gene expression in the rat hypothalamus. The levels of circulating gonadal steroids concurrently modulate both neuropeptides in male and female rats. However, it remains unkno...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054685
更新日期:2001-09-01 00:00:00
abstract::We have used excitatory amino acids as tools to elucidate changes in hypothalamic function associated with lactation, focusing on the regulation of luteinizing hormone (LH) and prolactin secretion. In these studies, we have compared the responsiveness to NMA (N-methyl-D,L-aspartate), an agonist for the N-methyl-D-aspa...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126576
更新日期:1993-10-01 00:00:00
abstract::The exact physiological basis of acute growth hormone (GH) suppression by oral glucose is not fully understood. Glucose-mediated increase in hypothalamic somatostatin seems to be the most plausible explanation. Attempts to better understand its underlying mechanisms are compromised by species disparities in the respon...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000497214
更新日期:2019-01-01 00:00:00
abstract::As part of an assessment of endocrine influences on the actions of morphine, we have studied the effects of intracerebroventricular administration of somatostatin and thyrotropin releasing hormone (TRH) on the antinociceptive, temperature and cataleptic responses to subcutaneous morphine in both intact and hypophysect...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123586
更新日期:1983-12-01 00:00:00
abstract::It has been well documented that interleukin-1beta (IL-1beta) is a major mediator for recruiting the hypothalamo-pituitary-adrenal (HPA) axis following infectious disease. The recent localization of IL-1beta receptors in neurons of the hippocampus provides further support for the role of IL-1beta as a neurotransmitter...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054405
更新日期:1999-02-01 00:00:00
abstract::The hypothesis was tested that corticotropin-releasing factor (CRF) is involved in the inhibition of gonadotropin secretion during chronic hyperprolactinemia. Two models of hyperprolactinemia were used, namely inoculation with the prolactin (PRL)-secreting tumor 7315b and implantation of isogenic pituitary glands. Gon...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125348
更新日期:1990-03-01 00:00:00
abstract::The present study examined the effect of estradiol on hypothalamic serotonin-1A (5-HT(1A)) receptor signaling in female rats. We first examined the time-course effects of a single injection of the 5-HT(1A) receptor agonist (+/-)8-OH-DPAT (5, 15 or 30 min prior to decapitation), and dose response of (+)8-OH-DPAT (50, 1...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000080795
更新日期:2004-01-01 00:00:00
abstract::Patients with active acromegaly are frequently insulin resistant, glucose intolerant, and at risk for developing overt type 2 diabetes. At the same time, these patients have a relatively lean phenotype associated with mobilization and oxidation of free fatty acids. These features are reversed by curative surgical remo...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000430819
更新日期:2016-01-01 00:00:00
abstract::Previous work in many laboratories has shown that luteinizing hormone-releasing hormone (LHRH) neurons display a range of shapes from smooth-contoured to extremely irregular or 'thorny'. To determine if these forms reflect or can be modified by the gonadal steroid milieu, the morphology of LHRH neurons was examined in...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125138
更新日期:1989-04-01 00:00:00
abstract::Hypophysectomized male rats with adenohypophyses grafted under the kidney capsule (HG rat) for 3 weeks with or without estradiol implantation, were used to examine prolactin (PRL) secretion independent of hypothalamic influence. Changes in the circulating PRL concentration were monitored by taking blood samples every ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123146
更新日期:1981-03-01 00:00:00
abstract:BACKGROUND/OBJECTIVE:Cortisol is thought to be involved in the pathophysiology of affective disorders. Less attention has been given to other neuroendocrine factors. The aim of the present study was to test the hypothesis that adrenocortical steroids aldosterone and cortisol show different dynamic changes in the course...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000505921
更新日期:2020-01-01 00:00:00
abstract::The modulatory actions of ovarian steroids on the norepinephrine (NE) induced alterations in luteinizing hormone (LH) secretion were examined in male and female rats. Long-term (4 weeks) castrated male and female rats bearing chronic third-ventricle cannulae were implanted with intra-atrial catheters. Animals were ble...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124581
更新日期:1986-01-01 00:00:00
abstract::Blood samples were removed via chronic intra-atrial cannulae every 15 min in female rats during the estrous cycle, the last week of pregnancy, parturition and suckling. Growth hormone (GH) secretion during the estrous cycle is characterized by episodic release, occurring approximately once hourly. The surges in GH inc...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122525
更新日期:1976-01-01 00:00:00
abstract::Secretion of the growth hormone (GH) in spontaneously hypertensive (SH) male rats has been determined and compared with that of normotensive Wistar-Kyoto (WKY) controls. In a first set of experiments, plasma GH concentration and pituitary GH content were measured in SH rats 30, 60 and 90 days old. 30-day rats showed r...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125617
更新日期:1990-10-01 00:00:00
abstract::An ultradian rhythm in adrenal secretion of corticosterone has been described in awake rats using intra-adrenal microdialysis. To determine the role of the autonomic innervation of the adrenal on the expression of the corticosterone rhythm, adrenal extracellular fluid was sampled by intra-adrenal microdialysis in inta...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126645
更新日期:1994-02-01 00:00:00
abstract:BACKGROUND/AIMS:Estrogen receptor-alpha (ER alpha) splice variants are important for understanding estrogen effects on the brain and estrogen therapy pitfalls. We addressed the question whether a novel ER alpha splice variant TADDI is expressed at the protein level in the human brain and whether it changes in relation ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000158573
更新日期:2009-01-01 00:00:00
abstract::Many aspects of reproductive neuroendocrine function and sexual behavior are responsive to both androgens and estrogens, suggesting that receptors for these steroid hormones may reside within single cells in brain regions that control reproductive function. We determined the distribution of estrogen receptor-containin...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127039
更新日期:1995-11-01 00:00:00
abstract::We determined the effect of 17 beta-estradiol (E2) on synthesis and release of luteinizing hormone (LH) induced by drugs which activate intracellular signal transduction mechanisms in rat anterior pituitary cells. Cells were pretreated with E2 (6 x 10(-10) M) or diluent for 24 h, then washed and incubated for 4 h with...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125405
更新日期:1990-06-01 00:00:00
abstract::Chronic hyperprolactinemia in the rat is associated with suppression of plasma gonadotropin concentrations. The reduction of gonadotropins is considered to be due to either an inhibitory effect of prolactin (PRL) on pituitary gonadotropin secretion and/or suppression of hypothalamic gonadotropin-releasing hormone (GnR...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126355
更新日期:1993-01-01 00:00:00
abstract::Previous reports have shown that dopamine (DA) in the zona incerta (ZI) has a stimulatory effect on gonadotrophin release. We have now investigated the possibility that steroids exert their feedback effects on the release of luteinizing hormone (LH) via catecholamine systems in the ZI. Since the same steroid regimes a...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125708
更新日期:1991-02-01 00:00:00
abstract:BACKGROUND:Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) express insulin-like growth factor (IGF)-related factors [IGF1, IGF2; insulin receptor (IR)-A, IR-B; IGF-binding protein (IGFBP) 1-3] as well as somatostatin (SSTRs) and dopamine D2 receptors (D2Rs). OBJECTIVES:To (1) compare mRNA expression of IGF-rel...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000444280
更新日期:2016-01-01 00:00:00
abstract::Concentrations of luteinizing hormone (LH) and prolactin (Prl) in the serum of anestrous and cycling ewes were compared. The concentration of LH in serum and the frequency of episodic releases of LH were lower in anestrous than in cycling ewes. Concentrations of LH in serum rose as rapidly after ovariectomy of anestro...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122870
更新日期:1979-01-01 00:00:00
abstract::Neonatal rats exhibit a period of diminished pituitary and adrenocortical responses to stress during the first 2 weeks of life. Since thyroid hormones are known to affect brain development, modulation of these responses to stress by alterations in thyroid hormone status have been investigated in hypothyroid (Hypo) and...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125232
更新日期:1989-09-01 00:00:00
abstract::The expression of the mouse metallothionein-I (mMT) promoter/human growth hormone (hGH) fusion gene in transgenic mice leads to female sterility and major alterations in the function of the hypothalamic-adenohypophyseal system. These alterations include increases in median-eminence norepinephrine turnover and plasma L...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125743
更新日期:1991-04-01 00:00:00