scholarly journals KNDy (Kisspeptin/Neurokinin B/Dynorphin) Neurons Are Activated during Both Pulsatile and Surge Secretion of LH in the Ewe

Endocrinology ◽  
2012 ◽  
Vol 153 (11) ◽  
pp. 5406-5414 ◽  
Author(s):  
Christina M. Merkley ◽  
Katrina L. Porter ◽  
Lique M. Coolen ◽  
Stanley M. Hileman ◽  
Heather J. Billings ◽  
...  
Keyword(s):  
Negative Feedback ◽  
Positive Feedback ◽  
Neurokinin B ◽  
Lh Surge ◽  
Short And Long Term ◽  
Positive And Negative Feedback ◽  
Kndy Neurons ◽  
Lh Secretion

Abstract KNDy (kisspeptin/neurokinin B/dynorphin) neurons of the arcuate nucleus (ARC) appear to mediate the negative feedback actions of estradiol and are thought to be key regulators of pulsatile LH secretion. In the ewe, KNDy neurons may also be involved with the positive feedback actions of estradiol (E2) to induce the LH surge, but the role of kisspeptin neurons in the preoptic area (POA) remains unclear. The goal of this study was to identify which population(s) of kisspeptin neurons is (are) activated during the LH surge and in response to the removal of E2-negative feedback, using Fos as an index of neuronal activation. Dual-label immunocytochemistry for kisspeptin and Fos was performed on sections containing the ARC and POA from ewes during the luteal phase of the estrous cycle, or before or after the onset of the LH surge (experiment 1), and from ovary-intact, short-term (24 h) and long-term (>30 d) ovariectomized (OVX) ewes in anestrus (experiment 2). The percentage of kisspeptin neurons expressing Fos in both the ARC and POA was significantly higher during the LH surge. In contrast, the percentage of kisspeptin/Fos colocalization was significantly increased in the ARC, but not POA, after both short- and long-term E2 withdrawal. Thus, POA kisspeptin neurons in the sheep are activated during, and appear to contribute to, E2-positive feedback, whereas ARC kisspeptin (KNDy) neurons are activated during both surge and pulsatile modes of secretion and likely play a role in mediating both positive and negative feedback actions of E2 on GnRH secretion in the ewe.

scholarly journals KNDy Neurons Modulate the Magnitude of the Steroid-Induced Luteinizing Hormone Surges in Ovariectomized Rats

Endocrinology ◽  
2015 ◽  
Vol 156 (11) ◽  
pp. 4200-4213 ◽  
Author(s):  
Cleyde V. Helena ◽  
Natalia Toporikova ◽  
Bruna Kalil ◽  
Andrea M. Stathopoulos ◽  
Veronika V. Pogrebna ◽  
...  
Keyword(s):  
Negative Feedback ◽  
Arcuate Nucleus ◽  
Ovariectomized Rats ◽  
Neurokinin B ◽  
Lh Surge ◽  
Neuronal Populations ◽  
Lh Release ◽  
Positive And Negative Feedback ◽  
Kndy Neurons ◽  
Lh Secretion

Kisspeptin is the most potent stimulator of LH release. There are two kisspeptin neuronal populations in the rodent brain: in the anteroventral periventricular nucleus (AVPV) and in the arcuate nucleus. The arcuate neurons coexpress kisspeptin, neurokinin B, and dynorphin and are called KNDy neurons. Because estradiol increases kisspeptin expression in the AVPV whereas it inhibits KNDy neurons, AVPV and KNDy neurons have been postulated to mediate the positive and negative feedback effects of estradiol on LH secretion, respectively. Yet the role of KNDy neurons during the positive feedback is not clear. In this study, ovariectomized rats were microinjected bilaterally into the arcuate nucleus with a saporin-conjugated neurokinin B receptor agonist for targeted ablation of approximately 70% of KNDy neurons. In oil-treated animals, ablation of KNDy neurons impaired the rise in LH after ovariectomy and kisspeptin content in both populations. In estradiol-treated animals, KNDy ablation did not influence the negative feedback of steroids during the morning. Surprisingly, KNDy ablation increased the steroid-induced LH surges, accompanied by an increase of kisspeptin content in the AVPV. This increase seems to be due to lack of dynorphin input from KNDy neurons to the AVPV as the following: 1) microinjections of a dynorphin antagonist into the AVPV significantly increased the LH surge in estradiol-treated rats, similar to KNDy ablation, and 2) intra-AVPV microinjections of dynorphin in KNDy-ablated rats restored LH surge levels. Our results suggest that KNDy neurons provide inhibition to AVPV kisspeptin neurons through dynorphin and thus regulate the amplitude of the steroid-induced LH surges.

scholarly journals Release of Norepinephrine in the Preoptic Area Activates Anteroventral Periventricular Nucleus Neurons and Stimulates the Surge of Luteinizing Hormone

Endocrinology ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 363-374 ◽  
Author(s):  
Raphael E. Szawka ◽  
Maristela O. Poletini ◽  
Cristiane M. Leite ◽  
Marcelo P. Bernuci ◽  
Bruna Kalil ◽  
...  
Keyword(s):  
Positive Feedback ◽  
Preoptic Area ◽  
Lh Surge ◽  
Ovx Rats ◽  
Selective Lesion ◽  
Periventricular Nucleus ◽  
Reverse Microdialysis ◽  
Fos Expression ◽  
Lh Secretion

The role of norepinephrine (NE) in regulation of LH is still controversial. We investigated the role played by NE in the positive feedback of estradiol and progesterone. Ovarian-steroid control over NE release in the preoptic area (POA) was determined using microdialysis. Compared with ovariectomized (OVX) rats, estradiol-treated OVX (OVX+E) rats displayed lower release of NE in the morning but increased release coincident with the afternoon surge of LH. OVX rats treated with estradiol and progesterone (OVX+EP) exhibited markedly greater NE release than OVX+E rats, and amplification of the LH surge. The effect of NE on LH secretion was confirmed using reverse microdialysis. The LH surge and c-Fos expression in anteroventral periventricular nucleus neurons were significantly increased in OVX+E rats dialyzed with 100 nm NE in the POA. After Fluoro-Gold injection in the POA, c-Fos expression in Fluoro-Gold/tyrosine hydroxylase-immunoreactive neurons increased during the afternoon in the A2 of both OVX+E and OVX+EP rats, in the locus coeruleus (LC) of OVX+EP rats, but was unchanged in the A1. The selective lesion of LC terminals, by intracerebroventricular N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine, reduced the surge of LH in OVX+EP but not in OVX+E rats. Thus, estradiol and progesterone activate A2 and LC neurons, respectively, and this is associated with the increased release of NE in the POA and the magnitude of the LH surge. NE stimulates LH secretion, at least in part, through activation of anteroventral periventricular neurons. These findings contribute to elucidation of the role played by NE during the positive feedback of ovarian steroids.

scholarly journals Positive, But Not Negative Feedback Actions of Estradiol in Adult Female Mice Require Estrogen Receptor α in Kisspeptin Neurons

Endocrinology ◽  
2015 ◽  
Vol 156 (3) ◽  
pp. 1111-1120 ◽  
Author(s):  
Sharon L. Dubois ◽  
Maricedes Acosta-Martínez ◽  
Mary R. DeJoseph ◽  
Andrew Wolfe ◽  
Sally Radovick ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Adult Female ◽  
Negative Feedback ◽  
Positive Feedback ◽  
Estrogen Receptor Α ◽  
Female Mice ◽  
Lh Secretion ◽  
Express Estrogen Receptor ◽  
Specific Deletion

Abstract Hypothalamic kisspeptin (Kiss1) neurons express estrogen receptor α (ERα) and exert control over GnRH/LH secretion in female rodents. It has been proposed that estradiol (E2) activation of ERα in kisspeptin neurons in the arcuate nucleus (ARC) suppresses GnRH/LH secretion (negative feedback), whereas E2 activation of ERα in kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) mediates the release of preovulatory GnRH/LH surges (positive feedback). To test these hypotheses, we generated mice bearing kisspeptin cell–specific deletion of ERα (KERαKO) and treated them with E2 regimens that evoke either negative or positive feedback actions on GnRH/LH secretion. Using negative feedback regimens, as expected, E2 effectively suppressed LH levels in ovariectomized (OVX) wild-type (WT) mice to the levels seen in ovary-intact mice. Surprisingly, however, despite the fact that E2 regulation of Kiss1 mRNA expression was abrogated in both the ARC and AVPV of KERαKO mice, E2 also effectively decreased LH levels in OVX KERαKO mice to the levels seen in ovary-intact mice. Conversely, using a positive feedback regimen, E2 stimulated LH surges in WT mice, but had no effect in KERαKO mice. These experiments clearly demonstrate that ERα in kisspeptin neurons is required for the positive, but not negative feedback actions of E2 on GnRH/LH secretion in adult female mice. It remains to be determined whether the failure of KERαKO mice to exhibit GnRH/LH surges reflects the role of ERα in the development of kisspeptin neurons, in the active signaling processes leading to the release of GnRH/LH surges, or both.

scholarly journals Different Effects of Supervisor Positive and Negative Feedback on Subordinate In-Role and Extra-Role Performance: The Moderating Role of Regulatory Focus

2022 ◽  
Vol 12 ◽  
Author(s):  
Weilin Su ◽  
Shuai Yuan ◽  
Qian Qi
Keyword(s):  
Negative Feedback ◽  
Positive Feedback ◽  
Regulatory Focus ◽  
Academic Research ◽  
Role Performance ◽  
Subordinate Performance ◽  
Positive And Negative Feedback ◽  
The Relationship ◽  
Moderating Role

As an important tool for supervisors to intervene subordinates’ work and influence their performance, supervisor feedback has gradually become a new academic research hotspot. In this study, we build and verify a theoretical model to explore the different effects of supervisor positive and negative feedback on subordinate in-role and extra-role performance, and the moderating role of regulatory focus in these relationships. With data from pairing samples of 403 Chinese employees and their direct supervisors, the results indicate that supervisor positive feedback is positively related to subordinate in-role and extra-role performance. Supervisor negative feedback is positively related to subordinate in-role performance and negatively related to subordinate extra-role performance. Regulatory focus of subordinate can moderate the influence of supervisor positive feedback on subordinate in-role and extra-role performance, but it cannot moderate the influence of supervisor negative feedback on subordinate in-role and extra-role performance. That means when subordinates have promotion focus, the influence of supervisor positive feedback on their in-role performance and extra-role performance was stronger than those with prevention focus. These results further enrich the research on the relationship between supervisor feedback and subordinate performance, especially the different effects of positive and negative feedback from supervisor on subordinate with different regulatory focus. All conclusions from the analyses above not only further verify and develop some previous points on supervisor feedback and subordinate performance, but also derive certain management implications for promoting subordinate in-role and extra-role performance from the perspective of supervisor positive and negative feedback.

scholarly journals Differential Expression of Estrogen Receptors in the Hypothalamus Underlies the Bimodal Effects of Estradiol on Luteinizing Hormone Release

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A536-A537
Author(s):  
Patricia Costa Henriques ◽  
Nayara Soares Sena Aquino ◽  
Roberta Araújo-Lopes ◽  
Juneo Freitas Silva ◽  
Candido Celso Coimbra ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Estrogen Receptors ◽  
Negative Feedback ◽  
Feedback Effects ◽  
Lh Surge ◽  
Neuronal Populations ◽  
17Β Estradiol ◽  
Lh Release ◽  
Positive And Negative Feedback

Abstract Low 17β-estradiol (E2) levels suppress luteinizing hormone (LH) release, while high E2 stimulates an LH surge in the positive-feedback required for ovulation. Kisspeptin (Kp) neurons in the anteroventral periventricular (AVPV) and arcuate (ARC) nuclei of hypothalamus have been implicated in E2 positive- and negative-feedback effects, respectively. However, how E2 differentially regulates these two neuronal populations remains unknown. We investigated whether neurons in the AVPV and ARC are differently responsive to changes in E2 levels and the regulatory role of estrogen receptors (ERs). Ovariectomized (OV) rats received oil or E2 at doses of 4 (OVE-4), 40 (OVE-40), or 80 (OVE-80) µg/kg. Rats on diestrus (DI) and proestrus (PRO) were used as physiological controls. OV rats were also treated with 0.02, 0.2 or 2.0 mg/kg of propyl pyrazole triol (PPT), or 6 mg/kg of diarylpropionitrile (DPN). Serial blood samples were collected for hormonal measurements. Brains were processed for immunohistochemistry and qPCR analyses in the AVPV and ARC. The E2 doses gradually increased plasma E2, with PRO levels being attained in OVE-80 rats. OVE-80 rats displayed a PRO-like LH surge, while LH levels were constantly suppressed in OVE-4 rats. Progesterone receptor (PR) was used as an index of E2 responsiveness. PR expression was increased in the AVPV of PRO and OVE-80 rats, associated with c-Fos expression and occurrence of LH surge. In the ARC, both low and high E2 induced PR expression and reduced the number of Kp-immunoreactive (ir) neurons, consistent with the negative feedback effects on LH. E2 at 4 or 80 µg/kg equally induced PR expression in 90% of ARC Kp-ir neurons. Despite the higher sensitivity to E2 in the ARC, the percentage of neurons expressing ERα was lower in the ARC compared with AVPV. However, Esr1 expression was 2-fold higher in the ARC than in AVPV for low E2 levels, whereas both Esr1 and Esr2 were more expressed in the AVPV under high E2 status. Notably, Esr1/Esr2 ratio was twice as high in the ARC as in the AVPV regardless of E2 levels, suggesting a stronger ERβ inhibition over ERα in the AVPV. Accordingly, ERα selective activation with PPT increased PR in the ARC at the doses of 0.2 and 2.0 mg/kg, reducing plasma LH, while only the highest dose was able to stimulate PR expression in the AVPV. ERβ activation with DPN, in turn, had no effect in OV rats but amplified the induction of AVPV PR and the size of the LH surge in OVE-80 rats. Thus, we provide evidence that ARC and AVPV neurons are responsive to low and high E2 levels, respectively. ARC is 10 times more sensitive to ERα activation than AVPV, whereas ERβ positively modulates AVPV responsiveness to high E2. These differential responses to E2 seem to be related to differences in the relative Esr1 and Esr2 expression in the ARC and AVPV. Our findings suggest that hypothalamic differences in the relative expression of ERs play a key role in the bimodal regulation of LH release by E2.

The Role of Ecopedological Parameters in Management Sustainability of Banat Lands

2018 ◽  
Vol 69 (3) ◽  
pp. 688-692
Author(s):  
Lucian Nita ◽  
Dorin Tarau ◽  
Gheorghe Rogobete ◽  
Simona Nita ◽  
Radu Bertici ◽  
...  
Keyword(s):  
Plant Nutrition ◽  
Physical State ◽  
Agricultural Land ◽  
Soil Characteristics ◽  
South West ◽  
Short And Long Term ◽  
Laboratory Investigations ◽  
Case Basis

The issue addressed relates to an area of 1891694 ha of which 1183343 ha are agricultural land (62, 56) located in the south-west of Romania and refer to the use of soil chemical and physical properties as an acceptor for certain crop systems, with minimal undesirable effects both for plants to be grown, as well as soil characteristics and groundwater surface quality. It is therefore necessary on a case-by-case basis, measure stoc or rect the acidic reaction by periodic or alkaline calculations, the improvement of plant nutrition conditions through ameliorative fertilization and the application of measures to improve the physical state, sufficient justification for the need to develop short and long term strategies for the protection and conservation of edifying factors and the need to respect the frequency of field and laboratory investigations at all 8x8 km grids of the National Soil-Grounds Monitoring System (organized by I.C.P.A.) and completing it with the relevant pedological and agrochemical studies.

Considering a Potential Role of Linalool as a Mood Stabilizer for Bipolar Disorder

2020 ◽  
Vol 26 (40) ◽  
pp. 5128-5133
Author(s):  
Kate Levenberg ◽  
Wade Edris ◽  
Martha Levine ◽  
Daniel R. George
Keyword(s):  
Bipolar Disorder ◽  
Treatment Options ◽  
Mood Stabilizer ◽  
Well Being ◽  
Epidemiologic Studies ◽  
Treatment Regimens ◽  
Bipolar Spectrum Disorders ◽  
Short And Long Term

Epidemiologic studies suggest that the lifetime prevalence of bipolar spectrum disorders ranges from 2.8 to 6.5 percent of the population. To decrease morbidity and mortality associated with disease progression, pharmacologic intervention is indicated for the majority of these patients. While a number of effective treatment regimens exist, many conventional medications have significant side effect profiles that adversely impact patients’ short and long-term well-being. It is thus important to continue advancing and improving therapeutic options available to patients. This paper reviews the limitations of current treatments and examines the chemical compound Linalool, an alcohol found in many plant species, that may serve as an effective mood stabilizer. While relatively little is known about Linalool and bipolar disorder, the compound has been shown to have antiepileptic, anti-inflammatory, anxiolytic, anti-depressive, and neurotrophic effects, with mechanisms that are comparable to current bipolar disorder treatment options.

Creativity in Sociocultural Systems

2019 ◽  
pp. 269-284
Author(s):  
Dean Keith Simonton
Keyword(s):  
Macro Level ◽  
Historical Overview ◽  
Creative Activity ◽  
Cross Sectional ◽  
Individual Level ◽  
Short And Long Term ◽  
The Cross ◽  
Sociocultural Systems

Although psychologists typically see creativity as an individual-level event, sociologists and cultural anthropologists are more likely to view it as a sociocultural phenomenon. This phenomenon takes place at the level of relatively large and enduring collectives, such as cultures, nations, and even whole civilizations. This chapter reviews the extensive research on such macro-level creativity. The review begins with a historical overview before turning to the cross-sectional research on the creative Ortgeist, a subject that encompasses the factors that influence the relative creativity of both preliterate cultures and entire modern nations. From there the chapter turns to role of the Zeitgeist in affecting the creativity of civilizations across time—the rise and fall of creative activity. This research examines both quantitative and qualitative causes that operate both short- and long-term.

scholarly journals When a Neonate Is Born, So Is a Microbiota

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 148
Author(s):  
Alessandra Coscia ◽  
Flaminia Bardanzellu ◽  
Elisa Caboni ◽  
Vassilios Fanos ◽  
Diego Giampietro Peroni
Keyword(s):  
Bacterial Colonization ◽  
Perinatal Period ◽  
Delivery Mode ◽  
Fetal Life ◽  
Assisted Reproduction Techniques ◽  
Neonatal Nutrition ◽  
Short And Long Term ◽  
Number Of Bacteria

In recent years, the role of human microbiota as a short- and long-term health promoter and modulator has been affirmed and progressively strengthened. In the course of one’s life, each subject is colonized by a great number of bacteria, which constitute its specific and individual microbiota. Human bacterial colonization starts during fetal life, in opposition to the previous paradigm of the “sterile womb”. Placenta, amniotic fluid, cord blood and fetal tissues each have their own specific microbiota, influenced by maternal health and habits and having a decisive influence on pregnancy outcome and offspring outcome. The maternal microbiota, especially that colonizing the genital system, starts to influence the outcome of pregnancy already before conception, modulating fertility and the success rate of fertilization, even in the case of assisted reproduction techniques. During the perinatal period, neonatal microbiota seems influenced by delivery mode, drug administration and many other conditions. Special attention must be reserved for early neonatal nutrition, because breastfeeding allows the transmission of a specific and unique lactobiome able to modulate and positively affect the neonatal gut microbiota. Our narrative review aims to investigate the currently identified pre- and peri-natal factors influencing neonatal microbiota, before conception, during pregnancy, pre- and post-delivery, since the early microbiota influences the whole life of each subject.

scholarly journals Suppression of personality variation in boldness during foraging in three-spined sticklebacks

2021 ◽  
Vol 75 (4) ◽  
Author(s):  
Hannah E. A. MacGregor ◽  
Aislinn Cottage ◽  
Christos C. Ioannou
Keyword(s):  
Negative Feedback ◽  
Risk Taking ◽  
Positive Feedback ◽  
Gasterosteus Aculeatus ◽  
Control Treatment ◽  
Refuge Use ◽  
Individual Level ◽  
Behavioural Type ◽  
State Behaviour

Abstract Consistent inter-individual variation in behaviour within a population, widely referred to as personality variation, can be affected by environmental context. Feedbacks between an individual’s behaviour and state can strengthen (positive feedback) or weaken (negative feedback) individual differences when experiences such as predator encounters or winning contests are dependent on behavioural type. We examined the influence of foraging on individual-level consistency in refuge use (a measure of risk-taking, i.e. boldness) in three-spined sticklebacks, Gasterosteus aculeatus, and particularly whether changes in refuge use depended on boldness measured under control conditions. In the control treatment trials with no food, individuals were repeatable in refuge use across repeated trials, and this behavioural consistency did not differ between the start and end of these trials. In contrast, when food was available, individuals showed a higher degree of consistency in refuge use at the start of the trials versus controls but this consistency significantly reduced by the end of the trials. The effect of the opportunity to forage was dependent on behavioural type, with bolder fish varying more in their refuge use between the start and the end of the feeding trials than shyer fish, and boldness positively predicted the likelihood of feeding at the start but not at the end of the trials. This suggests a state-behaviour feedback, but there was no overall trend in how bolder individuals changed their behaviour. Our study shows that personality variation can be suppressed in foraging contexts and a potential but unpredictable role of feedbacks between state and behaviour. Significance statement In this experimental study, we examined how foraging influences consistency in risk-taking in individual three-spined sticklebacks. We show that bolder individuals become less consistent in their risk-taking behaviour than shyer individuals during foraging. Some bolder individuals reinforce their risk-taking behaviour, suggesting a positive feedback between state and behaviour, while others converge on the behaviour of shyer individuals, suggesting a negative feedback. In support of a role of satiation in driving negative feedback effects, we found that bolder individuals were more likely to feed at the start but not at the end of the trials. Overall, our findings suggest that foraging can influence personality variation in risk-taking behaviour; however, the role of feedbacks may be unpredictable.

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