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Sample records for arcuate nucleus role

  1. Role of the hypothalamic arcuate nucleus in cardiovascular regulation.

    Science.gov (United States)

    Sapru, Hreday N

    2013-04-01

    Recently the hypothalamic arcuate nucleus (Arc) has been implicated in cardiovascular regulation. Both pressor and depressor responses can be elicited by the chemical stimulation of the Arc. The direction of cardiovascular responses (increase or decrease) elicited from the Arc depends on the baseline blood pressure. The pressor responses are mediated via increase in sympathetic nerve activity and involve activation of the spinal ionotropic glutamate receptors. Arc-stimulation elicits tachycardic responses which are mediated via inhibition of vagal input and excitation of sympathetic input to the heart. The pathways within the brain mediating the pressor and tachycardic responses elicited from the Arc have not been delineated. The depressor responses to the Arc-stimulation are mediated via the hypothalamic paraventricular nucleus (PVN). Gamma aminobutyric acid type A receptors, neuropeptide Y1 receptors, and opiate receptors in the PVN mediate the depressor responses elicited from the Arc. Some circulating hormones (e.g., leptin and insulin) may reach the Arc via the leaky blood-brain barrier and elicit their cardiovascular effects. Although the Arc is involved in mediating the cardiovascular responses to intravenously injected angiotensin II and angiotensin-(1-12), these effects may not be due to leakage of these peptides across the blood-brain barrier in the Arc; instead, circulating angiotensins may act on neurons in the SFO and mediate cardiovascular actions via the projections of SFO neurons to the Arc. Cardiovascular responses elicited by acupuncture have been reported to be mediated by direct and indirect projections of the Arc to the RVLM. PMID:23260431

  2. Interleukin-7, a new cytokine targeting the mouse hypothalamic arcuate nucleus: role in body weight and food intake regulation.

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    Laurence Macia

    Full Text Available Body weight is controlled through peripheral (white adipose tissue and central (mainly hypothalamus mechanisms. We have recently obtained evidence that overexpression of interleukin (IL-7, a critical cytokine involved in lymphopoiesis, can protect against the development of diet-induced obesity in mice. Here we assessed whether IL-7 mediated its effects by modulating hypothalamic function. Acute subcutaneous injection of IL-7 prevented monosodium glutamate-induced obesity, this being correlated with partial protection against cell death in the hypothalamic arcuate nucleus (ARC. Moreover, we showed that IL-7 activated hypothalamic areas involved in regulation of feeding behavior, as indicated by induction of the activation marker c-Fos in neural cells located in the ventromedial part of the ARC and by inhibition of food intake after fasting. Both chains of the IL-7 receptor (IL-7Ralpha and gamma(c were expressed in the ARC and IL-7 injection induced STAT-3 phosphorylation in this area. Finally, we established that IL-7 modulated the expression of neuropeptides that tune food intake, with a stimulatory effect on the expression of pro-opiomelanocortin and an inhibitory effect on agouti-related peptide expression in accordance with IL-7 promoting anorectic effects. These results suggest that the immunomodulatory cytokine IL-7 plays an important and unappreciated role in hypothalamic body weight regulation.

  3. Functional Heterogeneity of Arcuate Nucleus Pro-Opiomelanocortin Neurons: Implications for Diverging Melanocortin Pathways

    OpenAIRE

    Sohn, Jong-Woo; Williams, Kevin W.

    2012-01-01

    Arcuate nucleus (ARC) pro-opiomelanocortin (POMC) neurons are essential regulators of food intake, energy expenditure, and glucose homeostasis. POMC neurons integrate several key metabolic signals that include neurotransmitters and hormones. The change in activity of POMC neurons is relayed to melanocortin receptors in distinct regions of the central nervous system. This review will summarize the role of leptin and serotonin receptors in regulating the activity of POMC neurons and provide a m...

  4. Ghrelin stimulation of growth hormone-releasing hormone neurons is direct in the arcuate nucleus.

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    Guillaume Osterstock

    Full Text Available BACKGROUND: Ghrelin targets the arcuate nucleus, from where growth hormone releasing hormone (GHRH neurones trigger GH secretion. This hypothalamic nucleus also contains neuropeptide Y (NPY neurons which play a master role in the effect of ghrelin on feeding. Interestingly, connections between NPY and GHRH neurons have been reported, leading to the hypothesis that the GH axis and the feeding circuits might be co-regulated by ghrelin. PRINCIPAL FINDINGS: Here, we show that ghrelin stimulates the firing rate of identified GHRH neurons, in transgenic GHRH-GFP mice. This stimulation is prevented by growth hormone secretagogue receptor-1 antagonism as well as by U-73122, a phospholipase C inhibitor and by calcium channels blockers. The effect of ghrelin does not require synaptic transmission, as it is not antagonized by gamma-aminobutyric acid, glutamate and NPY receptor antagonists. In addition, this hypothalamic effect of ghrelin is independent of somatostatin, the inhibitor of the GH axis, since it is also found in somatostatin knockout mice. Indeed, ghrelin does not modify synaptic currents of GHRH neurons. However, ghrelin exerts a strong and direct depolarizing effect on GHRH neurons, which supports their increased firing rate. CONCLUSION: Thus, GHRH neurons are a specific target for ghrelin within the brain, and not activated secondary to altered activity in feeding circuits. These results support the view that ghrelin related therapeutic approaches could be directed separately towards GH deficiency or feeding disorders.

  5. High plasma triglyceride levels strongly correlate with low kisspeptin in the arcuate nucleus of male rats

    DEFF Research Database (Denmark)

    Overgaard, A; Axel, A M; Lie, M E;

    2015-01-01

    signals to the GnRH neurons. METHODS: In this study, we measured body weight and plasma concentrations of leptin, insulin, testosterone, and triglycerides after high fat diet exposure and correlated these parameters with the number of kisspeptin-immunoreactive neurons in the arcuate nucleus of male rats...... with increased fat in the diet. Kisspeptin-immunoreactive cells are not correlated with body weight, testosterone, leptin or insulin. However, we find that the number of kisspeptin-immunoreactive cells is strongly and negatively correlated with the level of plasma triglycerides (R2=0.49, p=0.004). CONCLUSION: We...... find a strong negative correlation between plasma triglyceride concentrations and the number of kisspeptin neurons in the rat arcuate nucleus regardless of the percentage of fat in the diet. In line with the lipotoxicity hypothesis, our results suggest that it is the level of hypertriglyceridemia per...

  6. Direct modulation of GFAP-expressing glia in the arcuate nucleus bi-directionally regulates feeding

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    Chen, Naiyan; Barak, Boaz; Sur, Mriganka

    2016-01-01

    Multiple hypothalamic neuronal populations that regulate energy balance have been identified. Although hypothalamic glia exist in abundance and form intimate structural connections with neurons, their roles in energy homeostasis are less known. Here we show that selective Ca2+ activation of glia in the mouse arcuate nucleus (ARC) reversibly induces increased food intake while disruption of Ca2+ signaling pathway in ARC glia reduces food intake. The specific activation of ARC glia enhances the activity of agouti-related protein/neuropeptide Y (AgRP/NPY)-expressing neurons but induces no net response in pro-opiomelanocortin (POMC)-expressing neurons. ARC glial activation non-specifically depolarizes both AgRP/NPY and POMC neurons but a strong inhibitory input to POMC neurons balances the excitation. When AgRP/NPY neurons are inactivated, ARC glial activation fails to evoke any significant changes in food intake. Collectively, these results reveal an important role of ARC glia in the regulation of energy homeostasis through its interaction with distinct neuronal subtype-specific pathways. DOI: http://dx.doi.org/10.7554/eLife.18716.001 PMID:27751234

  7. Effect of intermittent hypoxia on arcuate nucleus in the leptin-deficient rat.

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    Ciriello, John; Moreau, Jason M; McCoy, Aaron; Jones, Douglas L

    2016-07-28

    Intermittent hypoxia (IH) is a major pathophysiological consequence of obstructive sleep apnea. Recently, it has been shown that IH results in changes in body energy balance, leptin secretion and concomitant alterations in arcuate nucleus (ARC). In this study, the role of leptin on these changes was investigated in leptin-deficient rats exposed to IH or normoxic control conditions. Body weights, consumatory and locomotor behaviours, and protein signaling in ARC were assessed immediately after IH exposure. Compared to normoxia, IH altered body weight, food intake, locomotor pattern, and the plasma concentration of leptin and angiotensin II in the wild-type rat. However, these changes were not observed in the leptin-deficient rat. Within ARC of wild-type animals, IH increased phosphorylated signal transducer and activator of transcription 3 and pro-opiomelanocortin protein expression, but not in the leptin-deficient rat. The long-form leptin receptor protein expression was not altered following IH in either rat strain. These data suggest that leptin is involved in mediating the alterations to body energy balance and ARC activity following IH. PMID:27222924

  8. Magel2 is required for leptin-mediated depolarization of POMC neurons in the hypothalamic arcuate nucleus in mice.

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    Rebecca E Mercer

    Full Text Available Prader-Willi Syndrome is the most common syndromic form of human obesity and is caused by the loss of function of several genes, including MAGEL2. Mice lacking Magel2 display increased weight gain with excess adiposity and other defects suggestive of hypothalamic deficiency. We demonstrate Magel2-null mice are insensitive to the anorexic effect of peripherally administered leptin. Although their excessive adiposity and hyperleptinemia likely contribute to this physiological leptin resistance, we hypothesized that Magel2 may also have an essential role in intracellular leptin responses in hypothalamic neurons. We therefore measured neuronal activation by immunohistochemistry on brain sections from leptin-injected mice and found a reduced number of arcuate nucleus neurons activated after leptin injection in the Magel2-null animals, suggesting that most but not all leptin receptor-expressing neurons retain leptin sensitivity despite hyperleptinemia. Electrophysiological measurements of arcuate nucleus neurons expressing the leptin receptor demonstrated that although neurons exhibiting hyperpolarizing responses to leptin are present in normal numbers, there were no neurons exhibiting depolarizing responses to leptin in the mutant mice. Additional studies demonstrate that arcuate nucleus pro-opiomelanocortin (POMC expressing neurons are unresponsive to leptin. Interestingly, Magel2-null mice are hypersensitive to the anorexigenic effects of the melanocortin receptor agonist MT-II. In Prader-Willi Syndrome, loss of MAGEL2 may likewise abolish leptin responses in POMC hypothalamic neurons. This neural defect, together with increased fat mass, blunted circadian rhythm, and growth hormone response pathway defects that are also linked to loss of MAGEL2, could contribute to the hyperphagia and obesity that are hallmarks of this disorder.

  9. 胃和弓状核中obestatin在摄食行为调节中的作用%The roles of obestatin in stomach and hypothalamic arcuate nucleus of mice on the regulation of feeding behaviour

    Institute of Scientific and Technical Information of China (English)

    康冬梅; 赵翠平; 姚慧; 黄大可; 叶山东

    2012-01-01

    Objective To study the effects of change of feeding behaviour (including fasting and refeeding ) on the expression of obestatin in stomach and hypothalamic arcuate nucleus ( ARC ) of mice, to investigate the roles of obestatin on the regulation of food intake . Methods Fifty Kunming white male mice were divided into 5 groups in this study.Group A: fasted for 0 h, Group B: fasted for 24 h, Group C : fasted for 48 h, Group D: fasted for 72 h, Group E: refed for 4 h after 72 h fasted. The changes of the body weight in each group on different times of fast -ing and refeeding were obeserved.The expression of obestatin in the stomach and ARC were studied by the tech -nique of immunohistochemistry. Results Compared with Group A, the body weight was significantly reduced in Group B, C and D, and increased in Group E ( P < 0. 05 ). The expression of obestatin in the stomach and ARC in Group B showed no significant difference with Group E . Expressions of obestatin in the ARC and stomach correlated positively with the died body weights , and there were significant negative correlations with the variation of body weight Conclusion Obestatin expressions are change in the stomach and ARC after fasting and refeeding , which shows that obestatin may participate in the regulation of feeding behavior .%目的 观察摄食行为改变对小鼠胃和下丘脑弓状核中obestatin表达的影响,探讨obestatin在摄食行为调节中的作用.方法 50只雄性昆明种小鼠随机分为A、B、C、D、E 5组,分别为饥饿0、24、48、72 h及饥饿72 h后再进食4 h.分别于饥饿不同时段和饥饿后再进食时观察各组小鼠体重的变化;采用免疫组化法检测各组小鼠胃组织和弓状核中obestatin表达水平的变化.结果 与A组相比,B、C、D组小鼠体重均明显降低(P<0.01),E组小鼠体重增加(P<0.05).与A组比较,余4组胃和弓状核obestatin表达均明显降低(P<0.05),B、C、D、E组差异无统计学意义.线性

  10. Effects of insulin and leptin in the ventral tegmental area and arcuate hypothalamic nucleus on food intake and brain reward function in female rats

    OpenAIRE

    Bruijnzeel, Adrie W.; Corrie, Lu W.; Rogers, Jessica A.; Yamada, Hidetaka

    2011-01-01

    There is evidence for a role of insulin and leptin in food intake, but the effects of these adiposity signals on the brain reward system are not well understood. Furthermore, the effects of insulin and leptin on food intake in females are underinvestigated. These studies investigated the role of insulin and leptin in the ventral tegmental area (VTA) and the arcuate hypothalamic nucleus (Arc) on food intake and brain reward function in female rats. The intracranial self-stimulation procedure w...

  11. High plasma triglyceride levels strongly correlate with low kisspeptin in the arcuate nucleus of male rats

    DEFF Research Database (Denmark)

    Overgaard, A; Axel, A M; Lie, M E;

    2015-01-01

    signals to the GnRH neurons. METHODS: In this study, we measured body weight and plasma concentrations of leptin, insulin, testosterone, and triglycerides after high fat diet exposure and correlated these parameters with the number of kisspeptin-immunoreactive neurons in the arcuate nucleus of male rats....... In this model, a high fat diet (45% or 60% energy from fat, respectively) or a control diet (10% energy from fat) was provided after weaning for three months. RESULTS: We find a significant increase in body weight and plasma leptin concentration, but no change in the number of kisspeptin......-immunoreactive cells with increased fat in the diet. Kisspeptin-immunoreactive cells are not correlated with body weight, testosterone, leptin or insulin. However, we find that the number of kisspeptin-immunoreactive cells is strongly and negatively correlated with the level of plasma triglycerides (R2=0.49, p=0...

  12. An intact dorsomedial posterior arcuate nucleus is not necessary for photoperiodic responses in Siberian hamsters.

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    Teubner, Brett J W; Leitner, Claudia; Thomas, Michael A; Ryu, Vitaly; Bartness, Timothy J

    2015-04-01

    Seasonal responses of many animal species are triggered by changes in daylength and its transduction into a neuroendocrine signal by the pineal gland through the nocturnal duration of melatonin (MEL) release. The precise central sites necessary to receive, transduce, and relay the short day (SD) fall-winter MEL signals into seasonal responses and changes in physiology and behavior are unclear. In Siberian hamsters, SDs trigger decreases in body and lipid mass, testicular regression and pelage color changes. Several candidate genes and their central sites of expression have been proposed as components of the MEL transduction system with considerable recent focus on the arcuate nucleus (ARC) and its component, the dorsomedial posterior arcuate nucleus (dmpARC). This site has been postulated as a critical relay of SD information through the modulation of a variety of neurochemicals/receptors important for the control of energy balance. Here the necessity of an intact dmpARC for SD responses was tested by making electrolytic lesions of the Siberian hamster dmpARC and then exposing them to either long days (LD) or SDs for 12wks. The SD typical decreases in body and fat mass, food intake, testicular volume, serum testosterone concentrations, pelage color change and increased UCP-1 protein expression (a proxy for brown adipose tissue thermogenesis) all occurred despite the lack of an intact dmpARC. Although the Siberian hamster dmpARC contains photoperiod-modulated constituents, these data demonstrate that an intact dmpARC is not necessary for SD responses and not integral to the seasonal energy- and reproductive-related responses measured here.

  13. Retrograde study of CART- or NPY-neuronal projection from the hypothalamic arcuate nucleus to the dorsal raphe and/or the locus coeruleus in the rat.

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    Yoon, Ye S; Lee, Ji S; Lee, Hyun S

    2013-06-26

    The present study was designed to reveal cocaine- and amphetamine-regulated transcript (CART)- or neuropeptide Y (NPY)-immunoreactive neuronal projections from the hypothalamic arcuate nucleus (Arc) to the dorsal raphe (DR) and/or the locus coeruleus (LC) in the rat. Our results demonstrated that CART or NPY axon terminals formed close appositions to the neuronal profiles in the DR and the LC. Thus, arcuate sections were immunostained for the CART or NPY after the injections of green RetroBeads(™) into the DR and red tracer into the LC (or vice versa). First, retrogradely-labeled CART cells were mainly observed in the lateral Arc without colchicine. Of the total population of arcuate CART neurons, DR- and LC-projecting cells were 5.7% ± 0.9% and 6.6% ± 0.7%, respectively. In addition, a subset (3.3% ± 0.7%) of CART neurons provided divergent axon collaterals to the DR and the LC. Second, retrogradely-labeled NPY cells were observed in lateral or ventral borders of the medial Arc only after colchicine injection. Of the entire NPY cell population, DR- and LC-projecting neurons were 1.5% ± 0.3% and 1.3% ± 0.3%, respectively. Only a scanty proportion (0.1% ± 0.0%) sent axon collaterals to the DR and the LC. These observations suggested that arcuate CART or NPY system might have a potential influence on the brainstem monoaminergic nuclei, modulating their roles in feeding, nociception, emotional behaviors, arousal, and stress responses. Furthermore, a portion of arcuate CART neurons (along with only a few NPY cells) sending divergent axon collaterals to the DR/LC might have a simultaneous (and possibly more efficient) way to exert their specific influences on the monoaminergic nuclei.

  14. Early regulation of hypothalamic arcuate nucleus CART gene expression by short photoperiod in the Siberian hamster.

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    Mercer, Julian G; Ellis, Claire; Moar, Kim M; Logie, Tracy J; Morgan, Peter J; Adam, Clare L

    2003-03-28

    Cocaine- and amphetamine-regulated transcript (CART) mRNA is expressed in a number of hypothalamic nuclei including the arcuate nucleus (ARC). An increase in CART gene expression in the ARC of juvenile female Siberian hamsters (Phodopus sungorus) 14 days after transfer to short photoperiod at weaning and prior to major divergence of body weight trajectory in this seasonal mammal implicates CART in the induction of programmed weight change. In the current series of experiments, elevated CART mRNA in short photoperiod juvenile female animals relative to long photoperiod controls was apparent throughout the caudal-rostral extent of the ARC after 14 days, but was not observed when short photoperiod exposure was limited to 4-7 days. Elevated CART gene expression was also observed in juvenile males 14 days after transfer to short photoperiod at weaning, in adult female hamsters 14 days after transfer to short photoperiod and in adult male hamsters 21 days after transfer to short photoperiod. There were no consistent trends in expression levels of other energy balance-related genes with these relatively short duration photoperiod manipulations, suggesting that CART may be involved in short photoperiod-programmed body weight regulation.

  15. MCT2 expression and lactate influx in anorexigenic and orexigenic neurons of the arcuate nucleus.

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    Christian Cortes-Campos

    Full Text Available Hypothalamic neurons of the arcuate nucleus control food intake, releasing orexigenic and anorexigenic neuropeptides in response to changes in glucose concentration. Several studies have suggested that the glucosensing mechanism is governed by a metabolic interaction between neurons and glial cells via lactate flux through monocarboxylate transporters (MCTs. Hypothalamic glial cells (tanycytes release lactate through MCT1 and MCT4; however, similar analyses in neuroendocrine neurons have yet to be undertaken. Using primary rat hypothalamic cell cultures and fluorimetric assays, lactate incorporation was detected. Furthermore, the expression and function of MCT2 was demonstrated in the hypothalamic neuronal cell line, GT1-7, using kinetic and inhibition assays. Moreover, MCT2 expression and localization in the Sprague Dawley rat hypothalamus was analyzed using RT-PCR, in situ hybridization and Western blot analyses. Confocal immunohistochemistry analyses revealed MCT2 localization in neuronal but not glial cells. Moreover, MCT2 was localized to ∼90% of orexigenic and ~60% of anorexigenic neurons as determined by immunolocalization analysis of AgRP and POMC with MCT2-positives neurons. Thus, MCT2 distribution coupled with lactate uptake by hypothalamic neurons suggests that hypothalamic neurons control food intake using lactate to reflect changes in glucose levels.

  16. NPY and VGF Immunoreactivity Increased in the Arcuate Nucleus, but Decreased in the Nucleus of the Tractus Solitarius, of Type-II Diabetic Patients

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    Saderi, Nadia; Salgado-Delgado, Roberto; Avendaño-Pradel, Rafael; Basualdo, Maria del Carmen; Ferri, Gian-Luca; Chávez-Macías, Laura; Escobar, Carolina; Buijs, Ruud M.

    2012-01-01

    Ample animal studies demonstrate that neuropeptides NPY and α-MSH expressed in Arcuate Nucleus and Nucleus of the Tractus Solitarius, modulate glucose homeostasis and food intake. In contrast is the absence of data validating these observations for human disease. Here we compare the post mortem immunoreactivity of the metabolic neuropeptides NPY, αMSH and VGF in the infundibular nucleus, and brainstem of 11 type-2 diabetic and 11 non-diabetic individuals. α-MSH, NPY and tyrosine hydroxylase in human brain are localized in the same areas as in rodent brain. The similar distribution of NPY, α-MSH and VGF indicated that these neurons in the human brain may share similar functionality as in the rodent brain. The number of NPY and VGF immuno positive cells was increased in the infundibular nucleus of diabetic subjects in comparison to non-diabetic controls. In contrast, NPY and VGF were down regulated in the Nucleus of the Tractus Solitarius of diabetic patients. These results suggest an activation of NPY producing neurons in the arcuate nucleus, which, according to animal experimental studies, is related to a catabolic state and might be the basis for increased hepatic glucose production in type-2 diabetes. PMID:22808091

  17. Acute inflammation reduces kisspeptin immunoreactivity at the arcuate nucleus and decreases responsiveness to kisspeptin independently of its anorectic effects

    DEFF Research Database (Denmark)

    Castellano, J M; Bentsen, A H; Romero, M;

    2010-01-01

    Severe inflammatory challenges are frequently coupled to decreased food intake and disruption of reproductive function, the latter via deregulation of different signaling pathways that impinge onto GnRH neurons. Recently, the hypothalamic Kiss1 system, a major gatekeeper of GnRH function......-IR in the arcuate nucleus (ARC) that was not observed under conditions of metabolic stress induced by 48-h fasting. In addition, absolute responses to kisspeptin-10 (Kp-10), in terms of LH and testosterone secretion, were significantly attenuated in LPS-treated males that also displayed a decrease in food intake...... of hypothalamic kisspeptin immunoreactivity (IR) and hormonal responses to kisspeptin during the acute inflammatory phase. LPS injections induced a dramatic but transient drop of serum LH and testosterone levels. Suppression of gonadotropic function was associated with a significant decrease in kisspeptin...

  18. Functional expression of P2 purinoceptors in a primary neuroglial cell culture of the rat arcuate nucleus.

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    Pollatzek, Eric; Hitzel, Norma; Ott, Daniela; Raisl, Katrin; Reuter, Bärbel; Gerstberger, Rüdiger

    2016-07-01

    The arcuate nucleus (ARC) plays an important role in the hypothalamic control of energy homeostasis. Expression of various purinoceptor subtypes in the rat ARC and physiological studies suggest a modulatory function of P2 receptors within the neuroglial ARC circuitry. A differentiated mixed neuronal and glial microculture was therefore established from postnatal rat ARC, revealing neuronal expression of ARC-specific transmitters involved in food intake regulation (neuropeptide Y (NPY), proopiomelanocortin (POMC), tyrosine hydroxylase (TH)). Some NPYergic neurons cosynthesized TH, while POMC and TH expression proved to be mutually exclusive. Stimulation with the general purinoceptor agonists 2-methylthioadenosine-5'triphosphate (2-MeSATP) and ATP but not the P2X1/P2X3 receptor subtype agonist α,β-methyleneadenosine-5'triphosphate (α,β-meATP) induced intracellular calcium signals in ARC neurons and astrocytes. Some 5-10% each of 2-MeSATP responsive neurons expressed POMC, NYP or TH. Supporting the calcium imaging data, radioligand binding studies to hypothalamic membranes showed high affinity for 2-MeSATP, ATP but not α,β-meATP to displace [α-(35)S]deoxyadenosine-5'thiotriphosphate ([(35)S]dATPαS) from P2 receptors. Repetitive superfusion with equimolar 2-MeSATP allowed categorization of ARC cells into groups with a high or low (LDD) degree of purinoceptor desensitization, the latter allowing further receptor characterization. Calcium imaging experiments performed at 37°C vs. room temperature showed further reduction of desensitization. Agonist-mediated intracellular calcium signals were suppressed in all LDD neurons but only 25% of astrocytes in the absence of extracellular calcium, suggestive of metabotropic P2Y receptor expression in the majority of ARC astrocytes. The highly P2Y1-selective receptor agonists MRS2365 and 2-methylthioadenosine-5'diphosphate (2-MeSADP) activated 75-85% of all 2-MeSATP-responsive ARC astrocytes. Taking into consideration the

  19. Disparate Changes in Kisspeptin and Neurokinin B Expression in the Arcuate Nucleus After Sex Steroid Manipulation Reveal Differential Regulation of the Two KNDy Peptides in Rats

    DEFF Research Database (Denmark)

    Overgaard, Agnete; Ruiz-Pino, Francisco; Castellano, Juan M;

    2014-01-01

    Kisspeptin, neurokinin B (NKB) and dynorphin A are coexpressed in a population of neurons in the arcuate nucleus (ARC), termed KNDy neurons, which were recently recognized as important elements for the generation of GnRH pulses. However, the topographic distribution of these peptides and their re...

  20. Kisspeptin signalling in the hypothalamic arcuate nucleus regulates GnRH pulse generator frequency in the rat.

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    Xiao-Feng Li

    Full Text Available Kisspeptin and its G protein-coupled receptor (GPR 54 are essential for activation of the hypothalamo-pituitary-gonadal axis. In the rat, the kisspeptin neurons critical for gonadotropin secretion are located in the hypothalamic arcuate (ARC and anteroventral periventricular (AVPV nuclei. As the ARC is known to be the site of the gonadotropin-releasing hormone (GnRH pulse generator we explored whether kisspeptin-GPR54 signalling in the ARC regulates GnRH pulses.We examined the effects of kisspeptin-10 or a selective kisspeptin antagonist administration intra-ARC or intra-medial preoptic area (mPOA, (which includes the AVPV, on pulsatile luteinizing hormone (LH secretion in the rat. Ovariectomized rats with subcutaneous 17beta-estradiol capsules were chronically implanted with bilateral intra-ARC or intra-mPOA cannulae, or intra-cerebroventricular (icv cannulae and intravenous catheters. Blood samples were collected every 5 min for 5-8 h for LH measurement. After 2 h of control blood sampling, kisspeptin-10 or kisspeptin antagonist was administered via pre-implanted cannulae. Intranuclear administration of kisspeptin-10 resulted in a dose-dependent increase in circulating levels of LH lasting approximately 1 h, before recovering to a normal pulsatile pattern of circulating LH. Both icv and intra-ARC administration of kisspeptin antagonist suppressed LH pulse frequency profoundly. However, intra-mPOA administration of kisspeptin antagonist did not affect pulsatile LH secretion.These data are the first to identify the arcuate nucleus as a key site for kisspeptin modulation of LH pulse frequency, supporting the notion that kisspeptin-GPR54 signalling in this region of the mediobasal hypothalamus is a critical neural component of the hypothalamic GnRH pulse generator.

  1. Dopamine/Tyrosine Hydroxylase Neurons of the Hypothalamic Arcuate Nucleus Release GABA, Communicate with Dopaminergic and Other Arcuate Neurons, and Respond to Dynorphin, Met-Enkephalin, and Oxytocin

    OpenAIRE

    Zhang, Xiaobing; van den Pol, Anthony N.

    2015-01-01

    We employ transgenic mice with selective expression of tdTomato or cre recombinase together with optogenetics to investigate whether hypothalamic arcuate (ARC) dopamine/tyrosine hydroxylase (TH) neurons interact with other ARC neurons, how they respond to hypothalamic neuropeptides, and to test whether these cells constitute a single homogeneous population. Immunostaining with dopamine and TH antisera was used to corroborate targeted transgene expression. Using whole-cell recording on a large...

  2. Estradiol target neurons in the hypothalamic arcuate nucleus and lateral ventromedial nucleus of young adult, reproductively senescent, and monosodium glutamate-lesioned female golden hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Blaha, G.C.; Lamperti, A.A.

    1983-09-01

    Histoautoradiographic methods were used to assess estrogen target neurons in the hypothalamic arcuate nucleus (ARC) and ventromedial nucleus, lateral portion (LVM), comparing young adult and aged female golden hamsters. A subgroup of young adult females had ARC lesions induced by monosodium glutamate at neonatal day 8. All were ovariectomized to remove endogenous estrogens. Controls were given nonradioactive estradiol. After /sup 3/H-estradiol (/sup 3/H-E2) was injected intravenously, hypothalami were removed, frozen, and processed for histoautoradiography. In the ARC and LVM the ratio of /sup 3/H-E2 labelled neurons to total neurons counted was significantly lower in the older animals. Young females with ARC lesions had very few /sup 3/H-E2 labelled neurons remaining in the ARC but had a normal complement in the LVM. Although /sup 3/H-E2 labelled ARC neurons were notably decreased in old females, those ARC neurons that were labelled in the old had virtually the same frequency distribution of the labelling index as in the young, suggesting no change in the average estrogen uptake per target cell.

  3. Maternal Obesity in the Mouse Compromises the Blood-Brain Barrier in the Arcuate Nucleus of Offspring.

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    Kim, Dong Won; Glendining, Kelly A; Grattan, David R; Jasoni, Christine L

    2016-06-01

    The arcuate nucleus (ARC) regulates body weight in response to blood-borne signals of energy balance. Blood-brain barrier (BBB) permeability in the ARC is determined by capillary endothelial cells (ECs) and tanycytes. Tight junctions between ECs limit paracellular entry of blood-borne molecules into the brain, whereas EC transporters and fenestrations regulate transcellular entry. Tanycytes appear to form a barrier that prevents free diffusion of blood-borne molecules. Here we tested the hypothesis that gestation in an obese mother alters BBB permeability in the ARC of offspring. A maternal high-fat diet model was used to generate offspring from normal-weight (control) and obese dams (OffOb). Evans Blue diffusion into the ARC was higher in OffOb compared with controls, indicating that ARC BBB permeability was altered. Vessels investing the ARC in OffOb had more fenestrations than controls, although the total number of vessels was not changed. A reduced number of tanycytic processes in the ARC of OffOb was also observed. The putative transporters, Lrp1 and dysferlin, were up-regulated and tight junction components were differentially expressed in OffOb compared with controls. These data suggest that maternal obesity during pregnancy can compromise BBB formation in the fetus, leading to altered BBB function in the ARC after birth. PMID:27054554

  4. Photoperiodic regulation of histamine H3 receptor and VGF messenger ribonucleic acid in the arcuate nucleus of the Siberian hamster.

    Science.gov (United States)

    Barrett, Perry; Ross, Alexander W; Balik, Ales; Littlewood, Pauline A; Mercer, Julian G; Moar, Kim M; Sallmen, Tina; Kaslin, Jan; Panula, Pertti; Schuhler, Sandrine; Ebling, Francis J; Ubeaud, Caroline; Morgan, Peter J

    2005-04-01

    To survive winter the Siberian hamster has evolved profound physiological and behavioral adaptations, including a moult to winter pelage, regression of the reproductive axis, onset of daily torpor and increased capacity for thermogenesis. However, one of the most striking adaptations is the catabolism of intraabdominal and sc fat reserves contributing to the loss of up to 40% of body weight. These physiological and behavioral adaptations are photoperiodically driven, yet neither the site(s) in the brain nor the molecular mechanism(s) involved in the regulation of these profound adaptations is known. Here we report a dynamic regulation of gene expression in a dorsal region of the medial posterior area of the arcuate nucleus (dmpARC) of the Siberian and Syrian hamster brain in response to altered photoperiod. We show mRNA for the histamine H3 receptor is down-regulated and VGF is up-regulated in the dmpARC in hamsters switched from long- to short-day photoperiod. These data provide further evidence to support the view that the dmpARC is a major site to relay photoperiodic changes and as a site for the long-term regulation of seasonal physiology and behavior.

  5. Des-Acyl Ghrelin Directly Targets the Arcuate Nucleus in a Ghrelin-Receptor Independent Manner and Impairs the Orexigenic Effect of Ghrelin.

    Science.gov (United States)

    Fernandez, G; Cabral, A; Cornejo, M P; De Francesco, P N; Garcia-Romero, G; Reynaldo, M; Perello, M

    2016-02-01

    Ghrelin is a stomach-derived octanoylated peptide hormone that plays a variety of well-established biological roles acting via its specific receptor known as growth hormone secretagogue receptor (GHSR). In plasma, a des-octanoylated form of ghrelin, named des-acyl ghrelin (DAG), also exists. DAG is suggested to be a signalling molecule that has specific targets, including the brain, and regulates some physiological functions. However, no specific receptor for DAG has been reported until now, and, consequently, the potential role of DAG as a hormone has remained a matter of debate. In the present study, we show that DAG specifically binds to and acts on a subset of arcuate nucleus (ARC) cells in a GHSR-independent manner. ARC cells labelled by a DAG fluorescent tracer include the neuropeptide Y (NPY) and non-NPY neurones. Given the well-established role of the ARC in appetite regulation, we tested the effect of centrally administered DAG on food intake. We found that DAG failed to affect dark phase feeding, as well as food intake, after a starvation period; however, it impaired the orexigenic actions of peripherally administered ghrelin. Thus, we conclude that DAG directly targets ARC neurones and antagonises the orexigenic effects of peripherally administered ghrelin. PMID:26661382

  6. CAUDAL BRAINSTEM DELIVERY OF GHRELIN INDUCES FOS EXPRESSION IN THE NUCLEUS OF THE SOLITARY TRACT, BUT NOT IN THE ARCUATE OR PARAVENTRICULAR NUCLEI OF THE HYPOTHALAMUS

    OpenAIRE

    Faulconbridge, Lucy F.; Grill, Harvey J.; Kaplan, Joel M.; Daniels, Derek

    2008-01-01

    Ghrelin increases food intake when injected into either the forebrain or hindbrain ventricles. Brain areas activated by ghrelin after forebrain delivery have been examined using Fos immunohistochemistry and include the hypothalamic arcuate (Arc) and paraventricular (PVN) nuclei, and the nucleus of the solitary tract (NTS) in the medulla. It is not clear, however, if ghrelin applied directly to the hindbrain activates forebrain structures. Therefore, we examined Fos expression in the Arc, PVN,...

  7. Monosodium glutamate-induced arcuate nucleus damage affects both natural torpor and 2DG-induced torpor-like hypothermia in Siberian hamsters.

    Science.gov (United States)

    Pelz, Kimberly M; Routman, David; Driscoll, Joseph R; Kriegsfeld, Lance J; Dark, John

    2008-01-01

    Siberian hamsters (Phodopus sungorus) have the ability to express daily torpor and decrease their body temperature to approximately 15 degrees C, providing a significant savings in energy expenditure. Daily torpor in hamsters is cued by winterlike photoperiods and occurs coincident with the annual nadirs in body fat reserves and chronic leptin concentrations. To better understand the neural mechanisms underlying torpor, Siberian hamster pups were postnatally treated with saline or MSG to ablate arcuate nucleus neurons that likely possess leptin receptors. Body temperature was studied telemetrically in cold-acclimated (10 degrees C) male and female hamsters moved to a winterlike photoperiod (10:14-h light-dark cycle) (experiments 1 and 2) or that remained in a summerlike photoperiod (14:10-h light-dark cycle) (experiment 3). In experiment 1, even though other photoperiodic responses persisted, MSG-induced arcuate nucleus ablations prevented the photoperiod-dependent torpor observed in saline-treated Siberian hamsters. MSG-treated hamsters tended to possess greater fat reserves. To determine whether reductions in body fat would increase frequency of photoperiod-induced torpor after MSG treatment, hamsters underwent 2 wk of food restriction (70% of ad libitum) in experiment 2. Although food restriction did increase the frequency of torpor in both MSG- and saline-treated hamsters, it failed to normalize the proportion of MSG-treated hamsters undergoing photoperiod-dependent torpor. In experiment 3, postnatal MSG treatments reduced the proportion of hamsters entering 2DG-induced torpor-like hypothermia by approximately 50% compared with saline-treated hamsters (38 vs. 72%). In those MSG-treated hamsters that did become hypothermic, their minimum temperature during hypothermia was significantly greater than comparable saline-treated hamsters. We conclude that 1) arcuate nucleus mechanisms mediate photoperiod-induced torpor, 2) food-restriction-induced torpor may also be

  8. Moderate long-term modulation of neuropeptide Y in hypothalamic arcuate nucleus induces energy balance alterations in adult rats.

    Directory of Open Access Journals (Sweden)

    Lígia Sousa-Ferreira

    Full Text Available Neuropeptide Y (NPY produced by arcuate nucleus (ARC neurons has a strong orexigenic effect on target neurons. Hypothalamic NPY levels undergo wide-ranging oscillations during the circadian cycle and in response to fasting and peripheral hormones (from 0.25 to 10-fold change. The aim of the present study was to evaluate the impact of a moderate long-term modulation of NPY within the ARC neurons on food consumption, body weight gain and hypothalamic neuropeptides. We achieved a physiological overexpression (3.6-fold increase and down-regulation (0.5-fold decrease of NPY in the rat ARC by injection of AAV vectors expressing NPY and synthetic microRNA that target the NPY, respectively. Our work shows that a moderate overexpression of NPY was sufficient to induce diurnal over-feeding, sustained body weight gain and severe obesity in adult rats. Additionally, the circulating levels of leptin were elevated but the immunoreactivity (ir of ARC neuropeptides was not in accordance (POMC-ir was unchanged and AGRP-ir increased, suggesting a disruption in the ability of ARC neurons to response to peripheral metabolic alterations. Furthermore, a dysfunction in adipocytes phenotype was observed in these obese rats. In addition, moderate down-regulation of NPY did not affect basal feeding or normal body weight gain but the response to food deprivation was compromised since fasting-induced hyperphagia was inhibited and fasting-induced decrease in locomotor activity was absent.These results highlight the importance of the physiological ARC NPY levels oscillations on feeding regulation, fasting response and body weight preservation, and are important for the design of therapeutic interventions for obesity that include the NPY.

  9. Leptin modulates the intrinsic excitability of AgRP/NPY neurons in the arcuate nucleus of the hypothalamus.

    Science.gov (United States)

    Baver, Scott B; Hope, Kevin; Guyot, Shannon; Bjørbaek, Christian; Kaczorowski, Catherine; O'Connell, Kristen M S

    2014-04-16

    The hypothalamic arcuate nucleus (ARH) is a brain region critical for regulation of food intake and a primary area for the action of leptin in the CNS. In lean mice, the adipokine leptin inhibits neuropeptide Y (NPY) and agouti-related peptide (AgRP) neuronal activity, resulting in decreased food intake. Here we show that diet-induced obesity in mice is associated with persistent activation of NPY neurons and a failure of leptin to reduce the firing rate or hyperpolarize the resting membrane potential. However, the molecular mechanism whereby diet uncouples leptin's effect on neuronal excitability remains to be fully elucidated. In NPY neurons from lean mice, the Kv channel blocker 4-aminopyridine inhibited leptin-induced changes in input resistance and spike rate. Consistent with this, we found that ARH NPY neurons have a large, leptin-sensitive delayed rectifier K(+) current and that leptin sensitivity of this current is blunted in neurons from diet-induced obese mice. This current is primarily carried by Kv2-containing channels, as the Kv2 channel inhibitor stromatoxin-1 significantly increased the spontaneous firing rate in NPY neurons from lean mice. In HEK cells, leptin induced a significant hyperpolarizing shift in the voltage dependence of Kv2.1 but had no effect on the function of the closely related channel Kv2.2 when these channels were coexpressed with the long isoform of the leptin receptor LepRb. Our results suggest that dynamic modulation of somatic Kv2.1 channels regulates the intrinsic excitability of NPY neurons to modulate the spontaneous activity and the integration of synaptic input onto these neurons in the ARH.

  10. Changes in beta-endorphin neuron numbers and serum hormone levels in the arcuate nucleus of ovariectomized rats undergoing treadmill exercise

    Institute of Scientific and Technical Information of China (English)

    Weijie Zhang; Xiyi Liu

    2008-01-01

    BACKGROUND: The arcuate nucleus, when damaged in young rats, can lead to pathological changes in adults, such as osteoporosis. Ovariectomized rats suffer from osteoporosis at eight weeks following surgery and the number of β -endorphin immunoreactive neurons in the arcuate nucleus of the hypothalamus is significantly decreased. OBJECTIVE: To establish a rat model of osteoporosis using ovariectomy and to explore changes in the number of β -endorphin neurons and to correlate any such change with serum hormone levels in response to exercise or rest. DESIGN, TIME AND SETTING: The completely randomized block design, neural morphology study was performed at the Key Laboratory of Physiology, Guangdong Medical College, China between March 2004 and January 2005. MATERIALS: Sixteen healthy female rats were selected for ovariectomy. METHODS: Following model establishment, rats were assigned to either rest or exercise groups and each rat was housed individually. Rats in the exercise group underwent an exercise regimen using a treadmill. MAIN OUTCOME MEASURES: Eight weeks following exercise, radioirnmunoassay was performed to detect serum growth hormone, estrogen and osteocalcin levels. Immunohistochemistry was used to measure changes in the number of β -endorphin neurons in the arcuate nucleus of the hypothalamus. Changes in bone metabolism were assessed using bone histomorphometry. RESULTS: In the exercise group, the β -endorphin immunoreactive neurons were high in number, darkly stained, and the nucleus was not obvious. In the rest group, the β-endorphin immunoreactive neurons were low in number and lightly stained. The number of β-endorphin immunoreactive neurons in the exercise group was higher compared with the rest group (t = 2.83, P 0.05). Serum osteocalcin and growth hormone levels were significantly higher in the exercise group compared with the rest group (t = 2.78, 2.32, P < 0.05). Compared with the rest group, the percentage of trabecular bone area

  11. Arcuate NPY neurons sense and integrate peripheral metabolic signals to control feeding.

    Science.gov (United States)

    Kohno, Daisuke; Yada, Toshihiko

    2012-12-01

    NPY neuron in the hypothalamic arcuate nucleus is a key feeding center. Studies have shown that NPY neuron in the arcuate nucleus has a role to induce food intake. The arcuate nucleus is structurally unique with lacking blood brain barrier. Peripheral energy signals including hormones and nutrition can reach the arcuate nucleus. In this review, we discuss sensing and integrating peripheral signals in NPY neurons. In the arcuate nucleus, ghrelin mainly activates NPY neurons. Leptin and insulin suppress the ghrelin-induced activation in 30-40% of the ghrelin-activated NPY neurons. Lowering glucose concentration activates 40% of NPY neurons. These results indicate that NPY neuron in the arcuate nucleus is a feeding center in which major peripheral energy signals are directly sensed and integrated. Furthermore, there are subpopulations of NPY neurons in regard to their responsiveness to peripheral signals. These findings suggest that NPY neuron in the arcuate nucleus is an essential feeding center to induce food intake in response to peripheral metabolic state.

  12. An in vivo profile of beta-endorphin release in the arcuate nucleus and nucleus accumbens following exposure to stress or alcohol.

    Science.gov (United States)

    Marinelli, P W; Quirion, R; Gianoulakis, C

    2004-01-01

    The aim of the present study was to determine the effects of distinct categories of stressors on beta-endorphin (beta-EP) release in the arcuate nucleus (ArcN) and nucleus accumbens (NAcb) using in vivo microdialysis. Adult male rats were implanted with a cannula aimed at either the NAcb or the ArcN. On the day of testing, a 2 mm microdialysis probe was inserted into the cannula, and artificial cerebrospinal fluid was infused at 2.0 microl/min. After three baseline collections, animals either had a clothespin applied to the base of their tail for 20 min (a physical/tactile stressor), were exposed to fox urine odour for 20 min (a psychological stressor/species-specific threat), or were administered 2.4 g ethanol/kg body weight, 16.5% w/v, i.p. (a chemical/pharmacological stressor) with control animals receiving an equivalent volume of saline. Both tail-pinch and fox odour significantly increased beta-EP release from the ArcN (P<0.05), whilst only tail-pinch enhanced beta-EP release from the NAcb (P<0.01). On the other hand, alcohol stimulated beta-EP release in the NAcb as compared with saline-treated controls (P<0.01), but not in the ArcN. Although the increase in extracellular beta-EP produced by the other stressors was relatively rapid, there was a 90-min delay before alcohol administration caused beta-EP levels to exceed that of saline-injected controls. In conclusion, the fact that physical and fear-inducing psychological stressors stimulate beta-EP release in the ArcN and only physical stressors stimulate beta-EP release in the NAcb, indicates that stressors with different properties are processed differently in the brain. Also, an injection of alcohol caused a delayed increase of beta-EP in the NAcb but not the ArcN, indicating that alcohol may recruit a mechanism that is, at least partially, distinct from stress-related pathways. PMID:15283974

  13. Photoperiodic regulation of leptin sensitivity in the Siberian hamster, Phodopus sungorus, is reflected in arcuate nucleus SOCS-3 (suppressor of cytokine signaling) gene expression.

    Science.gov (United States)

    Tups, Alexander; Ellis, Claire; Moar, Kim M; Logie, Tracy J; Adam, Clare L; Mercer, Julian G; Klingenspor, Martin

    2004-03-01

    We present the first evidence that suppressor of cytokine signaling-3 (SOCS3), a protein inhibiting Janus kinase/signal transducer and activator of transcription (STAT) signaling distal of the leptin receptor, conveys seasonal changes in leptin sensitivity in the Siberian hamster. Food deprivation (48 h) reduced SOCS3 gene expression in hamsters acclimated to either long (LD) or short (SD) photoperiods, suggesting that leptin signals acute starvation regardless of photoperiod. However, SOCS3 mRNA levels were substantially lower in the hypothalamic arcuate nucleus of hamsters acclimated to SD than in those raised in LD. In juveniles raised in LD, a rapid increase in SOCS3 mRNA was observed within 4 d of weaning, which was completely prevented by transfer to SD on the day of weaning. The early increase in SOCS3 gene expression in juvenile hamsters in LD clearly preceded the establishment of different body weight trajectories in LD and SD. In adult LD hamsters, SOCS3 mRNA was maintained at an elevated level despite the chronic food restriction imposed to lower body weight and serum leptin to or even below SD levels. A single injection of leptin in SD hamsters elevated SOCS3 mRNA to LD levels, whereas leptin treatment had no effect on SOCS3 gene expression in LD hamsters. Our results suggest that the development of leptin resistance in LD-acclimated hamsters involves SOCS3-mediated suppression of leptin signaling in the arcuate nucleus. Increased SOCS3 expression in LD hamsters is independent of body fat and serum leptin levels, suggesting that the photoperiod is able to trigger the biannual reversible switch in leptin sensitivity.

  14. 甜味觉对大鼠弓状核NPY及FOS表达的影响%The effect of sweet taste stimulation on neuropeptide Y and FOS expression in the arcuate nucleus of the rat

    Institute of Scientific and Technical Information of China (English)

    朱永香; 王倩; 王爽; 贾敏; 杨颖; 于玮; 曹健; 南瑛

    2011-01-01

    Objective : To investigate the effect of sweet taste stimulation on neuropeptide Y and Fos expression in the arcuate nucleus of the rats.Methods: The experimental group rats intook sucrose solution 15mL , and the control group rats intook distilled water 15mL , 2 hours later, the expression of neuropeptide Y and Fos in the arcuate nucleus was detected by immunohistochemistry.Using statistical software to analyze the difference of neuropeptide Y and Fos expression in the arcuate nucleus between the experimental group and the control group.Results: Compared with the control group, neuropeptide Y and Fos expression in the arcuate nucleus in the experimental group rats significantly increased.Conclusion: Appetite-promoting effect of the sweet taste food may be related to activation of the arcuate nucleus NPY neurons and up-regulation of NPY.%目的:观察给SD大鼠摄入蔗糖甜味觉溶液后对弓状核内NPY及FOS表达的影响.方法:给实验组SD大鼠摄入15ml蔗糖溶液,给对照组SD大鼠摄入15ml蒸馏水,2h后应用免疫组织化学方法观察弓状核内NPY及FOS表达.应用统计软件分析实验组与对照组NPY及FOS表达情况的差异性.结果:与对照组相比,给大鼠蔗糖甜味觉溶液后引起弓状核NPY及FOS表达的显著增多.结论:甜味觉食物的促食欲作用可能与其激活了弓状核内的NPY能神经元,使NPY表达上调有关.

  15. Hypothalamic Paraventricular and Arcuate Nuclei Contribute to Elevated Sympathetic Nerve Activity in Pregnant Rats: Roles of Neuropeptide Y and α-Melanocyte-Stimulating Hormone.

    Science.gov (United States)

    Shi, Zhigang; Cassaglia, Priscila A; Gotthardt, Laura C; Brooks, Virginia L

    2015-12-01

    Pregnancy increases sympathetic nerve activity (SNA), but the mechanisms are unknown. Here, we investigated the contributions of the hypothalamic paraventricular and arcuate nuclei in α-chloralose-anesthetized pregnant and nonpregnant rats. Baseline arterial pressure (AP) was lower, and heart rate (HR), lumbar sympathetic activity, and splanchnic SNA were higher in pregnant rats compared with nonpregnant rats. Inhibition of the paraventricular nucleus via bilateral muscimol nanoinjections decreased AP and HR more in pregnant rats than in nonpregnant rats and decreased lumbar SNA only in pregnant rats. Similarly, after arcuate muscimol nanoninjections, the decreases in AP, HR, and lumbar, renal, and splanchnic sympathetic nerve activities were greater in pregnant rats than in nonpregnant rats. Major arcuate neuronal groups that project to the paraventricular nucleus express inhibitory neuropeptide Y (NPY) and excitatory α-melanocyte-stimulating hormone. Inhibition of paraventricular melanocortin 3/4 receptors with SHU9119 also decreased AP, HR, and lumbar SNA in pregnant rats but not in nonpregnant rats. Conversely, paraventricular nucleus NPY expression was reduced in pregnant animals, and although blockade of paraventricular NPY Y1 receptors increased AP, HR, and lumbar sympathetic activity in nonpregnant rats, it had no effects in pregnant rats. Yet, the sympathoinhibitory, depressor, and bradycardic effects of paraventricular NPY nanoinjections were similar between groups. In conclusion, the paraventricular and arcuate nuclei contribute to increased basal SNA during pregnancy, likely due in part to decreased tonic NPY inhibition and increased tonic α-melanocyte-stimulating hormone excitation of presympathetic neurons in the paraventricular nucleus.

  16. Hypothalamic Paraventricular and Arcuate Nuclei Contribute to Elevated Sympathetic Nerve Activity in Pregnant Rats: Roles of Neuropeptide Y and α-Melanocyte-Stimulating Hormone.

    Science.gov (United States)

    Shi, Zhigang; Cassaglia, Priscila A; Gotthardt, Laura C; Brooks, Virginia L

    2015-12-01

    Pregnancy increases sympathetic nerve activity (SNA), but the mechanisms are unknown. Here, we investigated the contributions of the hypothalamic paraventricular and arcuate nuclei in α-chloralose-anesthetized pregnant and nonpregnant rats. Baseline arterial pressure (AP) was lower, and heart rate (HR), lumbar sympathetic activity, and splanchnic SNA were higher in pregnant rats compared with nonpregnant rats. Inhibition of the paraventricular nucleus via bilateral muscimol nanoinjections decreased AP and HR more in pregnant rats than in nonpregnant rats and decreased lumbar SNA only in pregnant rats. Similarly, after arcuate muscimol nanoninjections, the decreases in AP, HR, and lumbar, renal, and splanchnic sympathetic nerve activities were greater in pregnant rats than in nonpregnant rats. Major arcuate neuronal groups that project to the paraventricular nucleus express inhibitory neuropeptide Y (NPY) and excitatory α-melanocyte-stimulating hormone. Inhibition of paraventricular melanocortin 3/4 receptors with SHU9119 also decreased AP, HR, and lumbar SNA in pregnant rats but not in nonpregnant rats. Conversely, paraventricular nucleus NPY expression was reduced in pregnant animals, and although blockade of paraventricular NPY Y1 receptors increased AP, HR, and lumbar sympathetic activity in nonpregnant rats, it had no effects in pregnant rats. Yet, the sympathoinhibitory, depressor, and bradycardic effects of paraventricular NPY nanoinjections were similar between groups. In conclusion, the paraventricular and arcuate nuclei contribute to increased basal SNA during pregnancy, likely due in part to decreased tonic NPY inhibition and increased tonic α-melanocyte-stimulating hormone excitation of presympathetic neurons in the paraventricular nucleus. PMID:26483343

  17. Leptin transiently antagonizes ghrelin and long-lastingly orexin in regulation of Ca2+ signaling in neuropeptide Y neurons of the arcuate nucleus

    Institute of Scientific and Technical Information of China (English)

    Daisuke Kohno; Shigetomo Suyama; Toshihiko Yada

    2008-01-01

    AIM: To explore the mechanism for interactions of leptin with ghrelin and orexin in the arcuate nucleus (ARC) activating neuropeptide Y (NPY) neurons during physiological regulation of feeding. METHODS: Single neurons from ARC of adult rats with matured feeding function were isolated. [Ca2+]I was measured to monitore their activities. The time course of leptin effects on ghrelin-induced versus orexin-induced [Ca2+]I increases in NPY neurons was studied. RESULTS: Administration of ghrelin or orexin-A at 10-10 mol/L increased cytosolic Ca2+ concentration ([Ca2+I) in NPY neurons isolated from the ARC of adult rats. Upon administration of leptin at 10-14-1012 mol/L, ghrelin-induced [Ca2+]I increases were initially (<10 min) inhibited but later restored, exhibiting a transient pattern of inhibition. In contrast, orexin-induced [Ca2+]I increases were inhibited by leptin in a long-lasting manner. Furthermore, a prior administration of leptin inhibited orexin action but not ghrelin action to increase [Ca2+]I. CONCLUSION: Leptin counteracted ghrelin effects transiently and orexin effects long-lastingly in NPY neurons. The transient property with which leptin counteracts ghrelin action in NPY neurons may allow the fasting-associated increase in ghrelin levels to activate NPY neurons in the presence of physiological leptin and to stimulate feeding.

  18. Differential gene regulation of GHSR signaling pathway in the arcuate nucleus and NPY neurons by fasting, diet-induced obesity, and 17β-estradiol.

    Science.gov (United States)

    Yasrebi, Ali; Hsieh, Anna; Mamounis, Kyle J; Krumm, Elizabeth A; Yang, Jennifer A; Magby, Jason; Hu, Pu; Roepke, Troy A

    2016-02-15

    Ghrelin's receptor, growth hormone secretagogue receptor (GHSR), is highly expressed in the arcuate nucleus (ARC) and in neuropeptide Y (NPY) neurons. Fasting, diet-induced obesity (DIO), and 17β-estradiol (E2) influence ARC Ghsr expression. It is unknown if these effects occur in NPY neurons. Therefore, we examined the expression of Npy, Agrp, and GHSR signaling pathway genes after fasting, DIO, and E2 replacement in ARC and pools of NPY neurons. In males, fasting increased ARC Ghsr and NPY Foxo1 but decreased NPY Ucp2. In males, DIO decreased ARC and NPY Ghsr and Cpt1c. In fed females, E2 increased Agrp, Ghsr, Cpt1c, and Foxo1 in ARC. In NPY pools, E2 decreased Foxo1 in fed females but increased Foxo1 in fasted females. DIO in females suppressed Agrp and augmented Cpt1c in NPY neurons. In summary, genes involved in GHSR signaling are differentially regulated between the ARC and NPY neurons in a sex-dependent manner.

  19. Young adult-specific hyperphagia in diabetic Goto-kakizaki rats is associated with leptin resistance and elevation of neuropeptide Y mRNA in the arcuate nucleus.

    Science.gov (United States)

    Maekawa, F; Fujiwara, K; Kohno, D; Kuramochi, M; Kurita, H; Yada, T

    2006-10-01

    The present study aimed to examine whether hyperphagia, which is frequently observed in type 1 diabetic patients and model animals, also occurs in type 2 diabetic Goto-Kakizaki (GK) rats and, if so, to explore underlying abnormalities in the hypothalamus. GK rats at postnatal weeks 6-12, compared to control Wistar rats, exhibited hyperphagia, hyperglycaemia, hyperleptinemia and increased visceral fat accumulation, whereas body weight was unaltered. The ability of leptin to suppress feeding was reduced in GK rats compared to Wistar rats of these ages. In GK rats, leptin-induced phosphorylation of signal transducer and activator of transcription 3 was significantly reduced in the cells of the hypothalamic arcuate nucleus (ARC), but not of the ventromedial hypothalamus, whereas the mRNA level of functional leptin receptor was unaltered. By real-time polymerase chain reaction and in situ hybridisation, mRNA levels of neuropeptide Y, but not pro-opiomelanocortin and galanin-like peptide, were significantly increased in the ARC of GK rats at 11 weeks, but not 26 weeks. Following i.c.v. injection of a NPY Y1 antagonist, 1229U91, the amount of food intake in GK rats was indistinguishable from that in Wistar rats, thus eliminating the hyperphagia of GK rats. These results demonstrate that young adult GK rats display hyperphagia in association with leptin resistance and increased NPY mRNA level in the ARC.

  20. Differential modulation of arcuate nucleus and mesolimbic gene expression levels by central leptin in rats on short-term high-fat high-sugar diet.

    Directory of Open Access Journals (Sweden)

    José K van den Heuvel

    Full Text Available OBJECTIVE: Leptin resistance is a common hallmark of obesity. Rats on a free-choice high-fat high-sugar (fcHFHS diet are resistant to peripherally administered leptin. The aim of this study was to investigate feeding responses to central leptin as well as the associated changes in mRNA levels in hypothalamic and mesolimbic brain areas. DESIGN AND METHODS: Rats on a CHOW or fcHFHS diet for 8 days received leptin or vehicle intracerebro(lateralventricularly (ICV and food intake was measured 5 h and 24 h later. Four days later, rats were sacrificed after ICV leptin or vehicle and mRNA levels were quantified for hypothalamic pro-opiomelanocortin (POMC and neuropeptide Y (NPY and for preproenkephalin (ppENK in nucleus accumbens and tyrosine hydroxylase (TH in ventral tegmental area (VTA. RESULTS: ICV leptin decreased caloric intake both in CHOW and fcHFHS rats. In fcHFHS, leptin preferentially decreased chow and fat intake. Leptin increased POMC and decreased NPY mRNA in CHOW, but not in fcHFHS rats. In CHOW rats, leptin had no effect on ppENK mRNA and decreased TH mRNA. In fcHFHS, leptin decreased ppENK mRNA and increased TH mRNA. CONCLUSION: Despite peripheral and arcuate leptin resistance, central leptin suppresses feeding in fcHFHS rats. As the VTA and nucleus accumbens are still responsive to leptin, these brain areas may therefore, at least partly, account for the leptin-induced feeding suppression in rats on a fcHFHS diet.

  1. Adjustment of acupuncture on arcuate nucleus of hypothalamus in obese rats%针剌对肥胖大鼠脑弓状核作用的调整

    Institute of Scientific and Technical Information of China (English)

    刘志诚; 孙凤岷; 袁锦虹; 姜军作; 衣运玲; 吕雅妮

    2005-01-01

    性作用可能是针灸减肥的作用机制之一.%BACKGROUND: The abnormality of the function of arcuate nucleus may be an important factor of obesity. It has been known that the mechanisms of acupuncture in treating obesity are related to nervous and neurohumoral regulation. What is the regulating effect of acupuncture on the function of arcuate nucleus?OBJECTIVE: To study the effects of acupuncture on the function of arcuate nucleus of obese rats, and further investigate central nervous functional mechanism of reducing weight by acupuncture.DESIGN: Randomized controlled study based on the experimental animals.SETTING: Acupuncture institute in second clinical medical college of a university of traditional Chinese medicine, and a population management college.MATERIALS: This experiment was carried out in the Acupuncture Institute of Second Clinical Medical College, Nanjing University of Traditional Chinese Medicine between April and October 2002. One-month old male SD rats just in ablactation were selected.METHODS: Rats fed with ordinary wholesome rat-feed were in the normal group. The successfully established experimental obese rats models were randomly divided as control group and acupuncture group with 12 rats in each group. Rats in the acupuncture group were given acupuncture treatment for 14 days, and rats in the normal and control groups were put into rat fixation-machine for 15 minutes every day, lasting for 14 days. Body mass, Lee' s index, body lipid, level of central and peripheral leptin and insulin(INS) as well as the frequency of spontaneous discharge of nerve cell in the arcuate nucleus(ARC) of hypothalamus in obese rats were observed with nervous electrophysiological and nervous biochemical technology before and after acupuncture.MAIN OUTCOME MEASURES: ① Effect of acupuncture on obesity index, fat contents of pericardium, kidney and epididymis of experimental obese rats. ② Effect of acupuncture on the frequency of spontaneous discharge of ARC

  2. Brain-derived neurotrophic factor is required for axonal growth of selective groups of neurons in the arcuate nucleus

    Directory of Open Access Journals (Sweden)

    Guey-Ying Liao

    2015-06-01

    Conclusion: This study shows that the majority of TrkB neurons in the ARH are distinct from known neuronal populations and that BDNF plays a critical role in directing projections from these neurons to the DMH and PVH. We propose that hyperphagic obesity due to BDNF deficiency is in part attributable to impaired axonal growth of TrkB-expressing ARH neurons.

  3. The ghrelin receptor agonist HM01 mimics the neuronal effects of ghrelin in the arcuate nucleus and attenuates anorexia-cachexia syndrome in tumor-bearing rats.

    Science.gov (United States)

    Borner, Tito; Loi, Laura; Pietra, Claudio; Giuliano, Claudio; Lutz, Thomas A; Riediger, Thomas

    2016-07-01

    The gastric hormone ghrelin positively affects energy balance by increasing food intake and reducing energy expenditure. Ghrelin mimetics are a possible treatment against cancer anorexia-cachexia syndrome (CACS). This study aimed to characterize the action of the nonpeptidergic ghrelin receptor agonist HM01 on neuronal function, energy homeostasis and muscle mass in healthy rats and to evaluate its possible usefulness for the treatment of CACS in a rat tumor model. Using extracellular single-unit recordings, we tested whether HM01 mimics the effects of ghrelin on neuronal activity in the arcuate nucleus (Arc). Furthermore, we assessed the effect of chronic HM01 treatment on food intake (FI), body weight (BW), lean and fat volumes, and muscle mass in healthy rats. Using a hepatoma model, we investigated the possible beneficial effects of HM01 on tumor-induced anorexia, BW loss, muscle wasting, and metabolic rate. HM01 (10(-7)-10(-6) M) mimicked the effect of ghrelin (10(-8) M) by increasing the firing rate in 76% of Arc neurons. HM01 delivered chronically for 12 days via osmotic minipumps (50 μg/h) increased FI in healthy rats by 24%, paralleled by increased BW, higher fat and lean volumes, and higher muscle mass. Tumor-bearing rats treated with HM01 had 30% higher FI than tumor-bearing controls and were protected against BW loss. HM01 treatment resulted in higher muscle mass and fat mass. Moreover, tumor-bearing rats reduced their metabolic rate following HM01 treatment. Our studies substantiate the possible therapeutic usefulness of ghrelin receptor agonists like HM01 for the treatment of CACS and possibly other forms of disease-related anorexia and cachexia. PMID:27147616

  4. The ghrelin receptor agonist HM01 mimics the neuronal effects of ghrelin in the arcuate nucleus and attenuates anorexia-cachexia syndrome in tumor-bearing rats.

    Science.gov (United States)

    Borner, Tito; Loi, Laura; Pietra, Claudio; Giuliano, Claudio; Lutz, Thomas A; Riediger, Thomas

    2016-07-01

    The gastric hormone ghrelin positively affects energy balance by increasing food intake and reducing energy expenditure. Ghrelin mimetics are a possible treatment against cancer anorexia-cachexia syndrome (CACS). This study aimed to characterize the action of the nonpeptidergic ghrelin receptor agonist HM01 on neuronal function, energy homeostasis and muscle mass in healthy rats and to evaluate its possible usefulness for the treatment of CACS in a rat tumor model. Using extracellular single-unit recordings, we tested whether HM01 mimics the effects of ghrelin on neuronal activity in the arcuate nucleus (Arc). Furthermore, we assessed the effect of chronic HM01 treatment on food intake (FI), body weight (BW), lean and fat volumes, and muscle mass in healthy rats. Using a hepatoma model, we investigated the possible beneficial effects of HM01 on tumor-induced anorexia, BW loss, muscle wasting, and metabolic rate. HM01 (10(-7)-10(-6) M) mimicked the effect of ghrelin (10(-8) M) by increasing the firing rate in 76% of Arc neurons. HM01 delivered chronically for 12 days via osmotic minipumps (50 μg/h) increased FI in healthy rats by 24%, paralleled by increased BW, higher fat and lean volumes, and higher muscle mass. Tumor-bearing rats treated with HM01 had 30% higher FI than tumor-bearing controls and were protected against BW loss. HM01 treatment resulted in higher muscle mass and fat mass. Moreover, tumor-bearing rats reduced their metabolic rate following HM01 treatment. Our studies substantiate the possible therapeutic usefulness of ghrelin receptor agonists like HM01 for the treatment of CACS and possibly other forms of disease-related anorexia and cachexia.

  5. Expression of RFamide-Related Peptide-3 (RFRP-3) mRNA in Dorsomedial Hypothalamic Nucleus and KiSS-1 mRNA in Arcuate Nucleus of Rat during Pregnancy

    Science.gov (United States)

    Sabet Sarvestani, Fatemeh; Tamadon, Amin; Koohi-Hosseinabadi, Omid; Mohammadi Nezhad, Saeed; Rahmanifar, Farhad; Jafarzadeh Shirazi, Mohammad Reza; Tanideh, Nader; Moghadam, Ali; Niazi, Ali

    2014-01-01

    Background RFamide-related peptide-3 (RFRP-3) and kisspeptin (KiSS-1) are known to respectively inhibit and stimulate gonadotropin releasing hormone (GnRH) and lute- inizing hormone (LH) secretion in rat. The aim of the present study was to evaluate the relative mRNA expression of RFRP-3 and KiSS-1 in the hypothalamus of pregnant rats. Materials and Methods In a randomized controlled experimental study, the exact preg- nancy day of 18 Sprague-Dawley rats were confirmed using the vaginal smear method and were equally assigned to three groups of days 7, 14 and 21 of pregnancy. Four non- pregnant female rats were ovariectomized and assigned as the control group. All rats were decapitated, and the dorsomedial hypothalamic nucleus (DMH) and the arcuate nucleus (ARC) for detection of KiSS-1 mRNA were separated from their hypothalamus to detect RFRP-3 and KiSS-1 mRNA respectively. Then, their relative expressions were compared between control and pregnant groups using real-time polymerase chain reac- tion (PCR). Results The relative expression of RFRP-3 mRNA in DMH did not change significantly during pregnancy (p>0.01). However, the relative expression of KiSS-1 mRNA in ARC was at its highest in day 7 of pregnancy and decreased until day 21 of pregnancy (p<0.01). Conclusion Decrease in GnRH and LH secretion during the pregnancy of rat may be controlled by constant expression of RFRP-3 mRNA and reduced expression of KiSS-1 mRNA in hypothalamus. PMID:25379163

  6. Expression of RFamide-Related Peptide-3 (RFRP-3 mRNA in Dorsomedial Hypothalamic Nucleus and KiSS-1 mRNA in Arcuate Nucleus of Rat during Pregnancy

    Directory of Open Access Journals (Sweden)

    Fatemeh Sabet Sarvestani

    2014-11-01

    Full Text Available Background: RFamide-related peptide-3 (RFRP-3 and kisspeptin (KiSS-1 are known to respectively inhibit and stimulate gonadotropin releasing hormone (GnRH and luteinizing hormone (LH secretion in rat. The aim of the present study was to evaluate the relative mRNA expression of RFRP-3 and KiSS-1 in the hypothalamus of pregnant rats. Materials and Methods: In a randomized controlled experimental study, the exact pregnancy day of 18 Sprague-Dawley rats were confirmed using the vaginal smear method and were equally assigned to three groups of days 7, 14 and 21 of pregnancy. Four nonpregnant female rats were ovariectomized and assigned as the control group. All rats were decapitated, and the dorsomedial hypothalamic nucleus (DMH and the arcuate nucleus (ARC for detection of KiSS-1 mRNA were separated from their hypothalamus to detect RFRP-3 and KiSS-1 mRNA respectively. Then, their relative expressions were compared between control and pregnant groups using real-time polymerase chain reaction (PCR. Results: The relative expression of RFRP-3 mRNA in DMH did not change significantly during pregnancy (p>0.01. However, the relative expression of KiSS-1 mRNA in ARC was at its highest in day 7 of pregnancy and decreased until day 21 of pregnancy (p<0.01. Conclusion: Decrease in GnRH and LH secretion during the pregnancy of rat may be controlled by constant expression of RFRP-3 mRNA and reduced expression of KiSS-1 mRNA in hypothalamus.

  7. Physical role for the nucleus in cell migration.

    Science.gov (United States)

    Fruleux, Antoine; Hawkins, Rhoda J

    2016-09-14

    Cell migration is important for the function of many eukaryotic cells. Recently the nucleus has been shown to play an important role in cell motility. After giving an overview of cell motility mechanisms we review what is currently known about the mechanical properties of the nucleus and the connections between it and the cytoskeleton. We also discuss connections to the extracellular matrix and mechanotransduction. We identify key physical roles of the nucleus in cell migration. PMID:27406341

  8. Physical role for the nucleus in cell migration

    Science.gov (United States)

    Fruleux, Antoine; Hawkins, Rhoda J.

    2016-09-01

    Cell migration is important for the function of many eukaryotic cells. Recently the nucleus has been shown to play an important role in cell motility. After giving an overview of cell motility mechanisms we review what is currently known about the mechanical properties of the nucleus and the connections between it and the cytoskeleton. We also discuss connections to the extracellular matrix and mechanotransduction. We identify key physical roles of the nucleus in cell migration.

  9. Glucose level determines excitatory or inhibitory effects of adiponectin on arcuate POMC neuron activity and feeding

    Science.gov (United States)

    Suyama, Shigetomo; Maekawa, Fumihiko; Maejima, Yuko; Kubota, Naoto; Kadowaki, Takashi; Yada, Toshihiko

    2016-01-01

    Adiponectin regulates glucose and lipid metabolism, acting against metabolic syndrome and atherosclerosis. Accumulating evidence suggest that adiponectin acts on the brain including hypothalamic arcuate nucleus (ARC), where proopiomelanocortin (POMC) neurons play key roles in feeding regulation. Several studies have examined intracerebroventricular (ICV) injection of adiponectin and reported opposite effects, increase or decrease of food intake. These reports used different nutritional states. The present study aimed to clarify whether adiponectin exerts distinct effects on food intake and ARC POMC neurons depending on the glucose concentration. Adiponectin was ICV injected with or without glucose for feeding experiments and administered to ARC slices with high or low glucose for patch clamp experiments. We found that adiponectin at high glucose inhibited POMC neurons and increased food intake while at low glucose it exerted opposite effects. The results demonstrate that glucose level determines excitatory or inhibitory effects of adiponectin on arcuate POMC neuron activity and feeding. PMID:27503800

  10. Glucose level determines excitatory or inhibitory effects of adiponectin on arcuate POMC neuron activity and feeding.

    Science.gov (United States)

    Suyama, Shigetomo; Maekawa, Fumihiko; Maejima, Yuko; Kubota, Naoto; Kadowaki, Takashi; Yada, Toshihiko

    2016-01-01

    Adiponectin regulates glucose and lipid metabolism, acting against metabolic syndrome and atherosclerosis. Accumulating evidence suggest that adiponectin acts on the brain including hypothalamic arcuate nucleus (ARC), where proopiomelanocortin (POMC) neurons play key roles in feeding regulation. Several studies have examined intracerebroventricular (ICV) injection of adiponectin and reported opposite effects, increase or decrease of food intake. These reports used different nutritional states. The present study aimed to clarify whether adiponectin exerts distinct effects on food intake and ARC POMC neurons depending on the glucose concentration. Adiponectin was ICV injected with or without glucose for feeding experiments and administered to ARC slices with high or low glucose for patch clamp experiments. We found that adiponectin at high glucose inhibited POMC neurons and increased food intake while at low glucose it exerted opposite effects. The results demonstrate that glucose level determines excitatory or inhibitory effects of adiponectin on arcuate POMC neuron activity and feeding. PMID:27503800

  11. The integrative role of the pedunculopontine nucleus in human gait.

    Science.gov (United States)

    Lau, Brian; Welter, Marie-Laure; Belaid, Hayat; Fernandez Vidal, Sara; Bardinet, Eric; Grabli, David; Karachi, Carine

    2015-05-01

    The brainstem pedunculopontine nucleus has a likely, although unclear, role in gait control, and is a potential deep brain stimulation target for treating resistant gait disorders. These disorders are a major therapeutic challenge for the ageing population, especially in Parkinson's disease where gait and balance disorders can become resistant to both dopaminergic medication and subthalamic nucleus stimulation. Here, we present electrophysiological evidence that the pedunculopontine and subthalamic nuclei are involved in distinct aspects of gait using a locomotor imagery task in 14 patients with Parkinson's disease undergoing surgery for the implantation of pedunculopontine or subthalamic nuclei deep brain stimulation electrodes. We performed electrophysiological recordings in two phases, once during surgery, and again several days after surgery in a subset of patients. The majority of pedunculopontine nucleus neurons (57%) recorded intrasurgically exhibited changes in activity related to different task components, with 29% modulated during visual stimulation, 41% modulated during voluntary hand movement, and 49% modulated during imaginary gait. Pedunculopontine nucleus local field potentials recorded post-surgically were modulated in the beta and gamma bands during visual and motor events, and we observed alpha and beta band synchronization that was sustained for the duration of imaginary gait and spatially localized within the pedunculopontine nucleus. In contrast, significantly fewer subthalamic nucleus neurons (27%) recorded intrasurgically were modulated during the locomotor imagery, with most increasing or decreasing activity phasically during the hand movement that initiated or terminated imaginary gait. Our data support the hypothesis that the pedunculopontine nucleus influences gait control in manners extending beyond simply driving pattern generation. In contrast, the subthalamic nucleus seems to control movement execution that is not likely to be gait

  12. Neuropeptide-Y in the paraventricular nucleus increases ethanol self-administration

    OpenAIRE

    Kelley, Stephen P; Nannini, Michelle A.; Bratt, Alison M.; Hodge, Clyde W.

    2001-01-01

    The paraventricular nucleus (PVN) of the hypothalamus is known to modulate feeding, obesity, and ethanol intake. Neuropeptide-Y (NPY), which is released endogenously by neurons projecting from the arcuate nucleus to the PVN, is one of the most potent stimulants of feeding behavior known. The role of NPY in the PVN on ethanol self-administration is unknown. To address this issue, rats were trained to self-administer ethanol via a sucrose fading procedure and injector guide cannulae aimed at th...

  13. On the Role of the Transition State Nucleus in Fission

    International Nuclear Information System (INIS)

    Although it is well-known that times. In order for fission to compete favourably with gamma-ray and neutron emission, a fixed amount of energy, equivalent to an activation energy in a chemical reaction, must be supplied to the heavy nucleus. This energy (often referred to as the fission threshold) is approximately 5 to 6 MeV for U238, and is the minimum energy required to produce the deformed transition state nucleus (zero internal excitation energy). In the process of stretching the original nucleus into the transition state nucleus (whose distortion is sometimes described as the saddle-point deformation), the increase in energy due to the short-range nuclear forces (surface tension) is greater than the decrease in energy due to the long-range Coulomb forces. However, as the particular distortion defining the transition state nucleus is approached, the decrease in Coulomb energy becomes equal to the increase in surface energy. The degree of distortion needed to produce the transition state nucleus is a function of several nuclear parameters and, hence, the saddle shape and threshold energy for fission change markedly for different nuclei. Since a large fraction of the excitation energy of the initial compound nucleus is consumed in deformation energy in passing to the fission saddle point, the transition state nucleus is thermodynamically ''cold''. Hence, for low excitation energies where the non-fission degrees of freedom favour the passage of the barrier with only a small kinetic energy, it seems reasonable to postulate that the traversal time of the saddle or the lifetime of the transition state nucleus is many orders of magnitude longer than the characteristic nuclear time. This leads to the prediction that the highly deformed transition state nucleus will have properties, including a spectrum of excited states, analogous to those of normal nuclei. Information on highly deformed transition state nuclei obtained by fission-fragment angular distribution studies

  14. Arcuate foramen and its clinical significance

    International Nuclear Information System (INIS)

    The present study determines the degree of ossification of the posterior atlanto-occipital membrane in dry bone, plane lateral cervical spine radiographs and computer tomography (CT). The average length, width and the area of the arcuate foramen were measured on dry bone and on cervical CT. Further, age, gender and complaints of the patients of shoulder and arm pain, neck pain, headache, vertigo, and lacrimation in relation to the presence of bony complete or incomplete arcuate foramen were evaluated. From February 2004 to January 2005 60 dry atlases were obtained from the Anatomy Department, University of Marmara, Istanbul, Turkey and 416 lateral cervical spine radiographs were obtained from the Radiology department for neurological and orthopedic evaluations. Each complete arcuate foramen was calculated with the aid of Clemex Vision PE demo version computer program. Among the 60 dry atlases examined 7 (11.7%) had complete and 2 (3.3 %) had incomplete bony bridge formation. Of the 416 plane lateral cervical spine radiographs examined, 30 (7.2%) had complete and 26 (6.25%) had incomplete bony bridge formation. Of the 30 complete arcuate foramen 24 (80%) were females and 6 (20%) were males. The frequency of having a complete arcuate foramen in females was 8.45%, and in males it was 4.55%. Further, of the 26 incomplete arcuate foramen 20 (76.9%) were females and 6 (23.1%) were males. The frequency of having an incomplete arcuate foramen in females was 7%, and in males was 4.55%. The statistical evaluations showed that patients with complete arcuate foramen had significant complaints of shoulder-arm pain (p=0.0072), neck pain (p=0.0072) and vertigo (p=0.0598) compared to patients with incomplete arcuate foramen. The patients with complete arcuate foramen had a headache ratio of 12:30 and this ratio was 2:26 in patients with incomplete arcuate foramen and the difference between complete and incomplete arcuate foramen was statistically significant (p=0.0062). Further

  15. Role of nucleus accumbens glutamatergic plasticity in drug addiction

    Directory of Open Access Journals (Sweden)

    Quintero GC

    2013-09-01

    Full Text Available Gabriel C Quintero1–31Florida State University – Panama, Clayton, Panama; 2Medical University of South Carolina, Charleston, South Carolina, USA; 3Smithsonian Tropical Research Institute, Ancon, Republic of PanamaAbstract: Substance dependence is characterized by a group of symptoms, according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR. These symptoms include tolerance, withdrawal, drug consumption for alleviating withdrawal, exaggerated consumption beyond original intention, failure to reduce drug consumption, expending a considerable amount of time obtaining or recovering from the substance’s effects, disregard of basic aspects of life (for example, family, and maintenance of drug consumption, despite facing adverse consequences. The nucleus accumbens (NAc is a brain structure located in the basal forebrain of vertebrates, and it has been the target of addictive drugs. Different neurotransmitter systems at the level of the NAc circuitry have been linked to the different problems of drug addiction, like compulsive use and relapse. The glutamate system has been linked mainly to relapse after drug-seeking extinction. The dopamine system has been linked mainly to compulsive drug use. The glutamate homeostasis hypothesis centers around the dynamics of synaptic and extrasynaptic levels of glutamate, and their impact on circuitry from the prefrontal cortex (PFC to the NAc. After repetitive drug use, deregulation of this homeostasis increases the release of glutamate from the PFC to the NAc during drug relapse. Glial cells also play a fundamental role in this hypothesis; glial cells shape the interactions between the PFC and the NAc by means of altering glutamate levels in synaptic and extrasynaptic spaces. On the other hand, cocaine self-administration and withdrawal increases the surface expression of subunit glutamate receptor 1 (GluA1 of alpha-amino-3-hydroxy-5-methyl-4

  16. Role of nucleus accumbens glutamatergic plasticity in drug addiction

    Science.gov (United States)

    Quintero, Gabriel C

    2013-01-01

    Substance dependence is characterized by a group of symptoms, according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR). These symptoms include tolerance, withdrawal, drug consumption for alleviating withdrawal, exaggerated consumption beyond original intention, failure to reduce drug consumption, expending a considerable amount of time obtaining or recovering from the substance’s effects, disregard of basic aspects of life (for example, family), and maintenance of drug consumption, despite facing adverse consequences. The nucleus accumbens (NAc) is a brain structure located in the basal forebrain of vertebrates, and it has been the target of addictive drugs. Different neurotransmitter systems at the level of the NAc circuitry have been linked to the different problems of drug addiction, like compulsive use and relapse. The glutamate system has been linked mainly to relapse after drug-seeking extinction. The dopamine system has been linked mainly to compulsive drug use. The glutamate homeostasis hypothesis centers around the dynamics of synaptic and extrasynaptic levels of glutamate, and their impact on circuitry from the prefrontal cortex (PFC) to the NAc. After repetitive drug use, deregulation of this homeostasis increases the release of glutamate from the PFC to the NAc during drug relapse. Glial cells also play a fundamental role in this hypothesis; glial cells shape the interactions between the PFC and the NAc by means of altering glutamate levels in synaptic and extrasynaptic spaces. On the other hand, cocaine self-administration and withdrawal increases the surface expression of subunit glutamate receptor 1 (GluA1) of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors at the level of the NAc. Also, cocaine self-administration and withdrawal induce the formation of subunit glutamate receptor 2 (GluA2), lacking the Ca2+-permeable AMPA receptors (CP-AMPARs) at the level of the NAc

  17. Role of nucleus accumbens glutamatergic plasticity in drug addiction.

    Science.gov (United States)

    Quintero, Gabriel C

    2013-01-01

    Substance dependence is characterized by a group of symptoms, according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR). These symptoms include tolerance, withdrawal, drug consumption for alleviating withdrawal, exaggerated consumption beyond original intention, failure to reduce drug consumption, expending a considerable amount of time obtaining or recovering from the substance's effects, disregard of basic aspects of life (for example, family), and maintenance of drug consumption, despite facing adverse consequences. The nucleus accumbens (NAc) is a brain structure located in the basal forebrain of vertebrates, and it has been the target of addictive drugs. Different neurotransmitter systems at the level of the NAc circuitry have been linked to the different problems of drug addiction, like compulsive use and relapse. The glutamate system has been linked mainly to relapse after drug-seeking extinction. The dopamine system has been linked mainly to compulsive drug use. The glutamate homeostasis hypothesis centers around the dynamics of synaptic and extrasynaptic levels of glutamate, and their impact on circuitry from the prefrontal cortex (PFC) to the NAc. After repetitive drug use, deregulation of this homeostasis increases the release of glutamate from the PFC to the NAc during drug relapse. Glial cells also play a fundamental role in this hypothesis; glial cells shape the interactions between the PFC and the NAc by means of altering glutamate levels in synaptic and extrasynaptic spaces. On the other hand, cocaine self-administration and withdrawal increases the surface expression of subunit glutamate receptor 1 (GluA1) of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors at the level of the NAc. Also, cocaine self-administration and withdrawal induce the formation of subunit glutamate receptor 2 (GluA2), lacking the Ca(2+)-permeable AMPA receptors (CP-AMPARs) at the level of the NAc

  18. Expression of GnRH in the hypothalamic arcuate nucleus in rats with diet-induced obesity and its influence on spermatogenesis%营养性肥胖大鼠弓状核促性腺激素释放激素的表达变化以及对精子发生的影响

    Institute of Scientific and Technical Information of China (English)

    刘冉冉; 赵方欣; 张洪芹

    2013-01-01

    Objective:To investigate the expressions of neuropeptide Y (NPY), obesity receptor (ob-R) and gonadotropin-re-leasing hormone (GnRH) in the hypothalamic arcuate nucleus in rats with diet-induced obesity and its influence on spermatogenesis. Methods:Weanling SD male rats were fed with high-energy feed. After 14 weeks, obesity models were selected according to Lee's Index. The rats in the control group were established by feeding them with normal feed. We observed the expressions of NPY. ob-R and GnRH in the hypothalamic arcuate nucleus and the expression of androgen binding protein (ABP) in the testis and the changes of spermatogenic cells cycle with obesity. We also detected the level of leptin,follicule-stimula-ting hormone (FSH), luteinizing hormone (LH) in serum and the concentration of testosterone in venous blood of testicle. Results:The level of leptin was higher in the obesity group than in the control group. The levels of testosterone, FSH and LH were lower than that in the control group. The expression of NPY increased, and the expressions of ob-R and GnRH decreased, as compared with the control group. The expression of ABP in testicles in obesity models was attenuated. The spermatogenic cells in S phase in obesity model decreased, while the cells in G2/M phase significantly increased. Conclusion:The low level of GnRH induced by neuroendocrine metabolic disorder lead to dysfunction of hypothalamic-pituitarytesticular axis, resulting in impediment of spermatogenesis, which might result in infertility.%目的:探讨营养性肥胖大鼠弓状核神经肽Y(NPY)、瘦素受体(ob-R)及与生殖相关的促性腺激素释放激素(GnRH)表达变化以及对精子发生的影响.方法:免疫组织化学观察NPY、ob R及GnRH在肥胖模型组下丘脑弓状核的表达情况以及睾丸支持细胞雄激素结合蛋白(ABP)表达变化;流式细胞分析检测睾丸生精细胞周期的改变.并测定血清中瘦素、睾酮、卵泡

  19. The role of the nucleus basalis of Meynert and reticular thalamic nucleus in pathogenesis of genetically determined absence epilepsy in rats : A lesion study

    NARCIS (Netherlands)

    Berdiev, R. K.; Chepurnov, S. A.; Veening, J. G.; Chepurnova, N. E.; van Luiftelaar, G.

    2007-01-01

    The role of cholinergic nucleus basalis (of Meynert) and the reticular thalamic nucleus in mechanisms of the generation spontaneous spike-and-wave discharges (SWDs) was investigated in the WAG/Rij rat model of absence epilepsy. Selective lesions were affected by local unilateral intraparenchymal inf

  20. Photoperiod regulates genes encoding melanocortin 3 and serotonin receptors and secretogranins in the dorsomedial posterior arcuate of the Siberian hamster.

    Science.gov (United States)

    Nilaweera, K N; Archer, Z A; Campbell, G; Mayer, C-D; Balik, A; Ross, A W; Mercer, J G; Ebling, F J P; Morgan, P J; Barrett, P

    2009-02-01

    The mechanism(s) involved in the regulation of the seasonal-appropriate body weight of the Siberian hamster are currently unknown. We have identified photoperiodically regulated genes including VGF in a sub-region of the arcuate nucleus termed the dorsomedial posterior arcuate (dmpARC). Gene expression changes in this nucleus so far account for a significant number of those reported as photoperiodically regulated and are therefore likely to contribute to seasonal physiological responses of the hamsters. The present study aimed to identify additional genes expressed in the dmpARC regulated by photoperiod that could be involved in regulating the activity of this nucleus with respect to seasonal physiology of the Siberian hamster. Using laser capture microdissection coupled with a microarray analysis and a candidate gene approach, we have identified several photoperiodically regulated genes in the dmpARC that are known to have roles in secretory and intracellular signalling pathways. These include secretogranin (sg) III and SgVI (secretory pathway), melanocortin 3 receptor (MC3-R) and serotonin (5-HT) receptors 2A and 7 (signalling pathway), all of which increase in expression under a short photoperiod. The spatial relationship between receptor signalling and potential secretory pathways was investigated by dual in situ hybridisation, which revealed that 5-HT2A and 5-HT7 receptors are expressed in neurones expressing VGF mRNA and that a sub-population (approximately 40%) of these neurones express MC3-R. These gene expression changes in dmpARC neurones may reflect the functional requirement of these neurones for seasonal physiological responses of the hamster.

  1. Role of the RVM in Descending Pain Regulation Originating from the Cerebrospinal Fluid-Contacting Nucleus.

    Science.gov (United States)

    Fei, Yan; Wang, Xin; Chen, Songsong; Zhou, Qiangqiang; Zhang, Chao; Li, Ying; Sun, Lihong; Zhang, Licai

    2016-07-01

    Evidence has suggested that cerebrospinal fluid-contacting nucleus (CSF-contacting nucleus) is correlated with the development and recurrence of pain. A recent research showed that the CSF-contacting nucleus acts as a component of the descending 5-hydroxytryptamine (5-HT) system and plays a role in descending pain inhibition. However, limited studies are conducted to investigate the relationship between the CSF-contacting nucleus and pain. In present study, we explored the effect of CSF-contacting nucleus on nociceptive behaviors in both normal and neuropathic rats via targeted ablation of the CSF-contacting nucleus in the brainstem, using cholera toxin subunit B-saporin (CB-SAP), a cytotoxin coupled to cholera toxin subunit B. The CB-SAP-treated rats showed aggravated thermal hyperalgesia and mechanical allodynia. Also, results from immunohistochemical experiments showed that rostral ventromedial medulla (RVM) received fiber projection from the CSF-contacting nucleus, which disappeared after ablation of the CSF-contacting nucleus, and the CB-SAP treated rats showed downregulation of c-Fos expression in the RVM as compared with the rats receiving i.c.v. injection of phosphate buffer saline (PBS). A significant downregulation of 5-HT-labeled neurons and tryptophan hydroxylase 2 (TPH2) as the marker of 5-HT cells in the RVM, and 5-HT expression in spinal dorsal horn in both normal and chronic constriction injury (CCI) rats after i.c.v. injection of CB-SAP was observed. These results suggested that RVM may be involved in descending pain modulation originating from the CSF-contacting nucleus. PMID:26961890

  2. ATG5: a distinct role in the nucleus.

    Science.gov (United States)

    Simon, Hans-Uwe; Friis, Robert

    2014-01-01

    Both apoptotic and autophagic pathways are activated in cells during anticancer treatment using DNA-damaging agents. Thus, the outcome is balanced between apoptotic cell death and enhanced autophagy, with the possibility of prolonged cell survival. It seems intuitively obvious that this survival mechanism might interfere with the desired tumor cell killing. We addressed this question by tipping the balance in favor of autophagy, using etoposide or cisplatin at low, sublethal doses. Over 4 days, only a little apoptosis was observed, but both drugs sharply increased autophagic flux. Surprisingly, cells underwent a cell cycle arrest at G 2/M, followed later by mitotic catastrophe with formation of multipolar spindles, missegregated chromosomes, or enlarged, irregular, sometimes multiple nuclei. Why? The answer is that even a low level of DNA damage not only upregulates autophagy, but also provokes the recruitment of an autophagy-related protein, ATG5, to the nucleus, where it binds BIRC5/survivin, thereby interfering with correct assembly of the chromosome passenger complex needed for cytokinesis.

  3. Deiters' Nucleus. Its Role in Cerebellar Ideogenesis : The Ferdinando Rossi Memorial Lecture.

    Science.gov (United States)

    Voogd, Jan

    2016-02-01

    Otto Deiters (1834-1863) was a promising neuroscientist who, like Ferdinando Rossi, died too young. His notes and drawings were posthumously published by Max Schultze in the book "Untersuchungen über Gehirn und Rückenmark." The book is well-known for his dissections of nerve cells, showing the presence of multiple dendrites and a single axon. Deiters also made beautiful drawings of microscopical sections through the spinal cord and the brain stem, the latter showing the lateral vestibular nucleus which received his name. This nucleus, however, should be considered as a cerebellar nucleus because it receives Purkinje cell axons from the vermal B zone in its dorsal portion. Afferents from the labyrinth occur in its ventral part. The nucleus gives rise to the lateral vestibulospinal tract. The cerebellar B module of which Deiters' nucleus is the target nucleus was used in many innovative studies of the cerebellum on the zonal organization of the olivocerebellar projection, its somatotopical organization, its microzones, and its role in posture and movement that are the subject of this review.

  4. The olfactory thalamus: unanswered questions about the role of the mediodorsal thalamic nucleus in olfaction.

    Science.gov (United States)

    Courtiol, Emmanuelle; Wilson, Donald A

    2015-01-01

    The mediodorsal thalamic nucleus (MDT) is a higher order thalamic nucleus and its role in cognition is increasingly well established. Interestingly, components of the MDT also have a somewhat unique sensory function as they link primary olfactory cortex to orbitofrontal associative cortex. In fact, anatomical evidence firmly demonstrates that the MDT receives direct input from primary olfactory areas including the piriform cortex and has dense reciprocal connections with the orbitofrontal cortex. The functions of this olfactory pathway have been poorly explored but lesion, imaging, and electrophysiological studies suggest that these connections may be involved in olfactory processing including odor perception, discrimination, learning, and attention. However, many important questions regarding the MDT and olfaction remain unanswered. Our goal here is not only to briefly review the existing literature but also to highlight some of the remaining questions that need to be answered to better define the role(s) of the MDT in olfactory processing.

  5. The role of meson exchange currents in charged current (anti)neutrino-nucleus scattering

    CERN Document Server

    Barbaro, M B; Caballero, J A; De Pace, A; Donnelly, T W; Megias, G D; Simo, I Ruiz

    2016-01-01

    We present our recent progress in the description of neutrino-nucleus interaction in the GeV region, of interest for ongoing and future oscillation experiments. In particular, we discuss the weak excitation of two-particle-two-hole states induced by meson exchange currents in a fully relativistic framework. We compare the results of our model with recent measurements of neutrino scattering cross sections, showing the crucial role played by two-nucleon knockout in the interpretation of the data.

  6. Sacral arcuate lines: Anatomy and pathologic conditions

    International Nuclear Information System (INIS)

    The sacrum is one of the most commonly radiographed bones of the human body as part of abdominal and pelvic radiologic examinations. This paper describes the radiologic anatomy of the sacral arcuate lines and presents a systematic approach to identifying pathologic conditions, for example, primary and metastatic malignancies, traumatic and osteoporotic fractures, vascular erosions from aneurysms, changes from neural tumors, and changes following radiation therapy

  7. Communication Between the Cell Membrane and the Nucleus: Role of Protein Compartmentalization

    Energy Technology Data Exchange (ETDEWEB)

    Lelievre, Sophie A; Bissell, Mina J

    1998-10-21

    Understanding how the information is conveyed from outside to inside the cell is a critical challenge for all biologists involved in signal transduction. The flow of information initiated by cell-cell and cell-extracellular matrix contacts is mediated by the formation of adhesion complexes involving multiple proteins. Inside adhesion complexes, connective membrane skeleton (CMS) proteins are signal transducers that bind to adhesion molecules, organize the cytoskeleton, and initiate biochemical cascades. Adhesion complex-mediated signal transduction ultimately directs the formation of supramolecular structures in the cell nucleus, as illustrated by the establishment of multi complexes of DNA-bound transcription factors, and the redistribution of nuclear structural proteins to form nuclear subdomains. Recently, several CMS proteins have been observed to travel to the cell nucleus, suggesting a distinctive role for these proteins in signal transduction. This review focuses on the nuclear translocation of structural signal transducers of the membrane skeleton and also extends our analysis to possible translocation of resident nuclear proteins to the membrane skeleton. This leads us to envision the communication between spatially distant cellular compartments (i.e., membrane skeleton and cell nucleus) as a bidirectional flow of information (a dynamic reciprocity) based on subtle multilevel structural and biochemical equilibria. At one level, it is mediated by the interaction between structural signal transducers and their binding partners, at another level it may be mediated by the balance and integration of signal transducers in different cellular compartments.

  8. LEPTIN SIGNALING IN THE NUCLEUS TRACTUS SOLITARII INCREASES SYMPATHETIC NERVE ACTIVITY TO THE KIDNEY

    OpenAIRE

    Mark, Allyn L.; Agassandian, Khristofor; Morgan, Donald A.; Liu, Xuebo; Cassell, Martin D.; Rahmouni, Kamal

    2008-01-01

    The hypothalamic arcuate nucleus was initially regarded as the principal site of leptin action, but there is increasing evidence for functional leptin receptors (Ob-Rb) in extra-hypothalamic sites, including the nucleus tractus solitarii (NTS). We previously demonstrated that arcuate injection of leptin increases sympathetic nerve activity (SNA) to brown adipose tissue (BAT) and kidney. In this study, we tested the hypothesis that leptin signaling in the NTS affects sympathetic neural outflow...

  9. Role of adrenomedullin in the cerebrospinal fluid-contacting nucleus in the modulation of immobilization stress.

    Science.gov (United States)

    Wu, Yue-Hong; Song, Si-Yuan; Liu, He; Xing, Dan; Wang, Xin; Fei, Yan; Li, Guang-Ling; Zhang, Chao; Li, Ying; Zhang, Li-Cai

    2015-06-01

    The contribution of the cerebrospinal fluid-contacting nucleus (CSF-contacting nucleus) and adrenomedullin (ADM) to the developmental modulation of stressful events remains controversial. This study explored the effects of endogenous ADM in the CSF-contacting nucleus on immobilization of stress-induced physiological parameter disorders and glucocorticoid hormone releasing hormone (CRH), rat plasma corticosterone expression, and verification of such effects by artificially lowering ADM expression in the CSF-contacting nucleus by targeted ablation of the nucleus. Immunohistochemical experiments showed that ADM-like immunoreactivity and the calcitonin receptor-like receptor (CRLR) marker were localized in the CSF-contacting nucleus. After 7 continuous days of chronic immobilization stress (CIS), animals exhibited anxiety-like behavior. Also, an increase in serum corticosterone, and enhanced expression of ADM in the CSF-contacting nucleus were observed, following activation by CIS. The intracerebroventricular (i.c.v.) administration of the ADM receptor antagonist AM22-52 significantly reduced ADM in the CSF-contacting nucleus, additionally, blocked the effects of ADM, meaning the expression of CRH in the hypothalamic paraventricular nucleus (Pa) and serum corticosterone level were increased, and the physiological parameters of the rats became correspondingly deteriorated. Additionally, the i.c.v. administration of cholera toxin subunit B-saporin (CB-SAP), a cytotoxin coupled to a cholera toxin subunit, completely eliminated the CSF-contacting nucleus, worsening the reaction of the body to CIS. The collective results demonstrated that ADM acted as a stress-related peptide in the CSF-contacting nucleus, and its lower expression and blocked effects in the nucleus contributed to the deterioration of stress-induced physiologic parameter disorders as well as the excessive expressions of stress-related hormones which were part of the hypothalamic-pituitary-adrenal (HPA) axis

  10. High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons

    Science.gov (United States)

    Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Padilla, Stephanie L; Palmiter, Richard D

    2016-01-01

    Kisspeptin (Kiss1) and neurokinin B (NKB) neurocircuits are essential for pubertal development and fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (Kiss1ARH) co-express Kiss1, NKB, dynorphin and glutamate and are postulated to provide an episodic, excitatory drive to gonadotropin-releasing hormone 1 (GnRH) neurons, the synaptic mechanisms of which are unknown. We characterized the cellular basis for synchronized Kiss1ARH neuronal activity using optogenetics, whole-cell electrophysiology, molecular pharmacology and single cell RT-PCR in mice. High-frequency photostimulation of Kiss1ARH neurons evoked local release of excitatory (NKB) and inhibitory (dynorphin) neuropeptides, which were found to synchronize the Kiss1ARH neuronal firing. The light-evoked synchronous activity caused robust excitation of GnRH neurons by a synaptic mechanism that also involved glutamatergic input to preoptic Kiss1 neurons from Kiss1ARH neurons. We propose that Kiss1ARH neurons play a dual role of driving episodic secretion of GnRH through the differential release of peptide and amino acid neurotransmitters to coordinate reproductive function. DOI: http://dx.doi.org/10.7554/eLife.16246.001 PMID:27549338

  11. High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons.

    Science.gov (United States)

    Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Padilla, Stephanie L; Palmiter, Richard D; Kelly, Martin J; Rønnekleiv, Oline K

    2016-01-01

    Kisspeptin (Kiss1) and neurokinin B (NKB) neurocircuits are essential for pubertal development and fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (Kiss1(ARH)) co-express Kiss1, NKB, dynorphin and glutamate and are postulated to provide an episodic, excitatory drive to gonadotropin-releasing hormone 1 (GnRH) neurons, the synaptic mechanisms of which are unknown. We characterized the cellular basis for synchronized Kiss1(ARH) neuronal activity using optogenetics, whole-cell electrophysiology, molecular pharmacology and single cell RT-PCR in mice. High-frequency photostimulation of Kiss1(ARH) neurons evoked local release of excitatory (NKB) and inhibitory (dynorphin) neuropeptides, which were found to synchronize the Kiss1(ARH) neuronal firing. The light-evoked synchronous activity caused robust excitation of GnRH neurons by a synaptic mechanism that also involved glutamatergic input to preoptic Kiss1 neurons from Kiss1(ARH) neurons. We propose that Kiss1(ARH) neurons play a dual role of driving episodic secretion of GnRH through the differential release of peptide and amino acid neurotransmitters to coordinate reproductive function. PMID:27549338

  12. Selecting danger signals: dissociable roles of nucleus accumbens shell and core glutamate in predictive fear learning.

    Science.gov (United States)

    Li, Susan S Y; McNally, Gavan P

    2015-06-01

    Conditioned stimuli (CSs) vary in their reliability as predictors of danger. Animals must therefore select among CSs those that are appropriate to enter into an association with the aversive unconditioned stimulus (US). The actions of prediction error instruct this stimulus selection so that when prediction error is large, attention to the CS is maintained and learning occurs but when prediction is small attention to the CS is withdrawn and learning is prevented. Here we studied the role of glutamate acting at rat nucleus accumbens shell (AcbSh) and core (AcbC) α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in this selection of danger signals. Using associative blocking and unblocking designs in rats, we show that antagonizing AcbSh AMPA receptors via infusions of 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo[f]quinoxaline-2,3-dione (NBQX; 0.5 μg) prevents the unblocking of fear learning, whereas antagonizing AcbC AMPA receptors via infusions of NBQX (0.5 μg) prevents both the blocking and unblocking of fear learning. These results identify dissociable but complementary roles for AcbSh and AcbC glutamate acting at AMPA receptors in selecting danger signals: AcbSh AMPA receptors upregulate attention and learning to CSs that signal surprising USs, whereas AcbC AMPA receptors encode the predicted outcome of each trial.

  13. The Role of the Suprachiasmatic Nucleus in Cardiac Autonomic Control during Sleep

    Science.gov (United States)

    Joustra, S. D.; Reijntjes, R. H.; Pereira, A. M.; Lammers, G. J.; Biermasz, N. R.; Thijs, R. D.

    2016-01-01

    Background The suprachiasmatic nucleus (SCN) may play an important role in central autonomic control, since its projections connect to (para)sympathetic relay stations in the brainstem and spinal cord. The cardiac autonomic modifications during nighttime may therefore not only result from direct effects of the sleep-related changes in the central autonomic network, but also from endogenous circadian factors as directed by the SCN. To explore the influence of the SCN on autonomic fluctuations during nighttime, we studied heart rate and its variability (HRV) in a clinical model of SCN damage. Methods Fifteen patients in follow-up after surgical treatment for nonfunctioning pituitary macroadenoma (NFMA) compressing the optic chiasm (8 females, 26–65 years old) and fifteen age-matched healthy controls (5 females, 30–63 years) underwent overnight ambulatory polysomnography. Eleven patients had hypopituitarism and received adequate replacement therapy. HRV was calculated for each 30-second epoch and corrected for sleep stage, arousals, and gender using mixed effect regression models. Results Compared to controls, patients spent more time awake after sleep onset and in NREM1-sleep, and less in REM-sleep. Heart rate, low (LF) and high frequency (HF) power components and the LF/HF ratio across sleep stages were not significantly different between groups. Conclusions These findings suggest that the SCN does not play a dominant role in cardiac autonomic control during sleep. PMID:27010631

  14. The Role of Nucleus Accumbens Shell in Learning about Neutral versus Excitatory Stimuli during Pavlovian Fear Conditioning

    Science.gov (United States)

    Bradfield, Laura A.; McNally, Gavan P.

    2010-01-01

    We studied the role of nucleus accumbens shell (AcbSh) in Pavlovian fear conditioning. Rats were trained to fear conditioned stimulus A (CSA) in Stage I, which was then presented in compound with a neutral stimulus and paired with shock in Stage II. AcbSh lesions had no effect on fear-learning to CSA in Stage I, but selectively prevented learning…

  15. The role of neurotensin in positive reinforcement in the rat central nucleus of amygdala.

    Science.gov (United States)

    László, Kristóf; Tóth, Krisztián; Kertes, Erika; Péczely, László; Lénárd, László

    2010-04-01

    In the central nervous system neurotensin (NT) acts as a neurotransmitter and neuromodulator. It was shown that NT has positive reinforcing effects after its direct microinjection into the ventral tegmental area. The central nucleus of amygdala (CeA), part of the limbic system, plays an important role in learning, memory, regulation of feeding, anxiety and emotional behavior. By means of immunohistochemical and radioimmune methods it was shown that the amygdaloid body is relatively rich in NT immunoreactive elements and NT receptors. The aim of our study was to examine the possible effects of NT on reinforcement and anxiety in the CeA. In conditioned place preference test male Wistar rats were microinjected bilaterally with 100 or 250 ng NT in volume of 0.4 microl or 35 ng neurotensin receptor 1 (NTS1) antagonist SR 48692 alone, or NTS1 antagonist 15 min before 100 ng NT treatment. Hundred or 250 ng NT significantly increased the time rats spent in the treatment quadrant. Prior treatment with the non-peptide NTS1 antagonist blocked the effects of NT. Antagonist itself did not influence the reinforcing effect. In elevated plus maze test we did not find differences among the groups as far as the anxiety index (time spent on the open arms) was concerned. Our results suggest that in the rat ACE NT has positive reinforcing effects. We clarified that NTS1s are involved in this action. It was also shown that NT does not influence anxiety behavior.

  16. Role of DNA methylation in the nucleus accumbens in incubation of cocaine craving.

    Science.gov (United States)

    Massart, Renaud; Barnea, Royi; Dikshtein, Yahav; Suderman, Matthew; Meir, Oren; Hallett, Michael; Kennedy, Pamela; Nestler, Eric J; Szyf, Moshe; Yadid, Gal

    2015-05-27

    One of the major challenges of cocaine addiction is the high rate of relapse to drug use after periods of withdrawal. During the first few weeks of withdrawal, cue-induced cocaine craving intensifies, or "incubates," and persists over extended periods of time. Although several brain regions and molecular mechanisms were found to be involved in this process, the underlying epigenetic mechanisms are still unknown. Herein, we used a rat model of incubation of cocaine craving, in which rats were trained to self-administer cocaine (0.75 mg/kg, 6 h/d, 10 d), and cue-induced cocaine-seeking was examined in an extinction test after 1 or 30 d of withdrawal. We show that the withdrawal periods, as well as cue-induced cocaine seeking, are associated with broad, time-dependent enhancement of DNA methylation alterations in the nucleus accumbens (NAc). These gene methylation alterations were partly negatively correlated with gene expression changes. Furthermore, intra-NAc injections of a DNA methyltransferase inhibitor (RG108, 100 μm) abolished cue-induced cocaine seeking on day 30, an effect that persisted 1 month, whereas the methyl donor S-adenosylmethionine (500 μm) had an opposite effect on cocaine seeking. We then targeted two proteins whose genes were demethylated by RG108-estrogen receptor 1 (ESR1) and cyclin-dependent kinase 5 (CDK5). Treatment with an intra-NAc injection of the ESR1 agonist propyl pyrazole triol (10 nm) or the CDK5 inhibitor roscovitine (28 μm) on day 30 of withdrawal significantly decreased cue-induced cocaine seeking. These results demonstrate a role for NAc DNA methylation, and downstream targets of DNA demethylation, in incubation of cocaine craving.

  17. Divergent roles of clock genes in retinal and suprachiasmatic nucleus circadian oscillators.

    Directory of Open Access Journals (Sweden)

    Guo-Xiang Ruan

    Full Text Available The retina is both a sensory organ and a self-sustained circadian clock. Gene targeting studies have revealed that mammalian circadian clocks generate molecular circadian rhythms through coupled transcription/translation feedback loops which involve 6 core clock genes, namely Period (Per 1 and 2, Cryptochrome (Cry 1 and 2, Clock, and Bmal1 and that the roles of individual clock genes in rhythms generation are tissue-specific. However, the mechanisms of molecular circadian rhythms in the mammalian retina are incompletely understood and the extent to which retinal neural clocks share mechanisms with the suprachiasmatic nucleus (SCN, the central neural clock, is unclear. In the present study, we examined the rhythmic amplitude and period of real-time bioluminescence rhythms in explants of retina from Per1-, Per2-, Per3-, Cry1-, Cry2-, and Clock-deficient mice that carried transgenic PERIOD2::LUCIFERASE (PER2::LUC or Period1::luciferase (Per1::luc circadian reporters. Per1-, Cry1- and Clock-deficient retinal and SCN explants showed weakened or disrupted rhythms, with stronger effects in retina compared to SCN. Per2, Per3, and Cry2 were individually dispensable for sustained rhythms in both tissues. Retinal and SCN explants from double knockouts of Cry1 and Cry2 were arrhythmic. Gene effects on period were divergent with reduction in the number of Per1 alleles shortening circadian period in retina, but lengthening it in SCN, and knockout of Per3 substantially shortening retinal clock period, but leaving SCN unaffected. Thus, the retinal neural clock has a unique pattern of clock gene dependence at the tissue level that it is similar in pattern, but more severe in degree, than the SCN neural clock, with divergent clock gene regulation of rhythmic period.

  18. Complementary roles of different oscillatory activities in the subthalamic nucleus in coding motor effort in Parkinsonism.

    Science.gov (United States)

    Tan, Huiling; Pogosyan, Alek; Anzak, Anam; Ashkan, Keyoumars; Bogdanovic, Marko; Green, Alexander L; Aziz, Tipu; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Brown, Peter

    2013-10-01

    The basal ganglia may play an important role in the control of motor scaling or effort. Recently local field potential (LFP) recordings from patients with deep brain stimulation electrodes in the basal ganglia have suggested that local increases in the synchronisation of neurons in the gamma frequency band may correlate with force or effort. Whether this feature uniquely codes for effort and whether such a coding mechanism holds true over a range of efforts is unclear. Here we investigated the relationship between frequency-specific oscillatory activities in the subthalamic nucleus (STN) and manual grips made with different efforts. The latter were self-rated using the 10 level Borg scale ranging from 0 (no effort) to 10 (maximal effort). STN LFP activities were recorded in patients with Parkinson's Disease (PD) who had undergone functional surgery. Patients were studied while motor performance was improved by dopaminergic medication. In line with previous studies we observed power increase in the theta/alpha band (4-12 Hz), power suppression in the beta band (13-30 Hz) and power increase in the gamma band (55-90 Hz) and high frequency band (101-375 Hz) during voluntary grips. Beta suppression deepened, and then reached a floor level as effort increased. Conversely, gamma and high frequency power increases were enhanced during grips made with greater effort. Multiple regression models incorporating the four different spectral changes confirmed that the modulation of power in the beta band was the only independent predictor of effort during grips made with efforts rated coding. The latter function is thought to be impaired in untreated PD where task-related reactivity in these two bands is deficient.

  19. NEW ASPECTS OF MELANOCORTIN SIGNALING: A ROLE FOR PRCP IN ALPHA-MSH DEGRADATION

    OpenAIRE

    Diano, Sabrina

    2010-01-01

    The role of the central melanocortin system in the regulation of energy metabolism has received much attention during the past decade since gene mutations of key components in melanocortin signaling cause monogenic forms of obesity in animals and humans. In the arcuate nucleus of the hypothalamus the prohormone proopiomelanocortin (POMC) is posttranslationally cleaved to produce α-melanocyte stimulating hormone (α-MSH), a peptide with anorexigenic effects upon activation of the melanocortin r...

  20. Neuromedin U in the paraventricular and arcuate hypothalamic nuclei increases non-exercise activity thermogenesis.

    Science.gov (United States)

    Novak, C M; Zhang, M; Levine, J A

    2006-08-01

    Brain neuromedin U (NMU) has been associated with the regulation of both energy intake and expenditure. We hypothesized that NMU induces changes in spontaneous physical activity and nonexercise activity thermogenesis (NEAT) through its actions on hypothalamic nuclei. We applied increasing doses of NMU directly to the paraventricular (PVN) and arcuate hypothalamic nuclei using chronic unilateral guide cannulae. In both nuclei, NMU significantly and dose-dependently increased physical activity and NEAT. Moreover, NMU increased physical activity and NEAT during the first hour of the dark phase, indicating that the reduction of sleep is unlikely to account for the increased physical activity seen with NMU treatment. As a positive control, we demonstrated that paraventricular NMU also significantly decreased food intake, as well as body weight. These data demonstrate that NMU is positively associated with NEAT through its actions in the PVN and arcuate nucleus. In co-ordination with its suppressive effects on feeding, the NEAT-activating effects of NMU make it a potential candidate in the combat of obesity. PMID:16867180

  1. The Role of the Nucleus Accumbens in Knowing when to Respond

    Science.gov (United States)

    Singh, Teghpal; McDannald, Michael A.; Takahashi, Yuji K.; Haney, Richard Z.; Cooch, Nisha K.; Lucantonio, Federica; Schoenbaum, Geoffrey

    2011-01-01

    While knowing what to expect is important, it is equally important to know when to expect it and to respond accordingly. This is apparent even in simple Pavlovian training situations in which animals learn to respond more strongly closer to reward delivery. Here we report that the nucleus accumbens core, an area well-positioned to represent…

  2. Neural set point for the control of arterial pressure: role of the nucleus tractus solitarius

    Directory of Open Access Journals (Sweden)

    Valentinuzzi Max E

    2010-01-01

    Full Text Available Abstract Background Physiological experiments have shown that the mean arterial blood pressure (MAP can not be regulated after chemo and cardiopulmonary receptor denervation. Neuro-physiological information suggests that the nucleus tractus solitarius (NTS is the only structure that receives information from its rostral neural nuclei and from the cardiovascular receptors and projects to nuclei that regulate the circulatory variables. Methods From a control theory perspective, to answer if the cardiovascular regulation has a set point, we should find out whether in the cardiovascular control there is something equivalent to a comparator evaluating the error signal (between the rostral projections to the NTS and the feedback inputs. The NTS would function as a comparator if: a its lesion suppresses cardiovascular regulation; b the negative feedback loop still responds normally to perturbations (such as mechanical or electrical after cutting the rostral afferent fibers to the NTS; c perturbation of rostral neural structures (RNS to the NTS modifies the set point without changing the dynamics of the elicited response; and d cardiovascular responses to perturbations on neural structures within the negative feedback loop compensate for much faster than perturbations on the NTS rostral structures. Results From the control theory framework, experimental evidence found currently in the literature plus experimental results from our group was put together showing that the above-mentioned conditions (to show that the NTS functions as a comparator are satisfied. Conclusions Physiological experiments suggest that long-term blood pressure is regulated by the nervous system. The NTS functions as a comparator (evaluating the error signal between its RNS and the cardiovascular receptor afferents and projects to nuclei that regulate the circulatory variables. The mean arterial pressure (MAP is regulated by the feedback of chemo and cardiopulmonary receptors and

  3. THE PREMULTIPLICATION NUCLEUS - ROLE IN MAINTAINING THE VALUE OF THE TECHNICAL MATERIAL PROPAGATING WINE

    Directory of Open Access Journals (Sweden)

    Adriana Costescu

    2012-04-01

    Full Text Available The strategy of developing the viticultural sector implies the restructuring of the national nursery system, as a result of implementing the European legislation, namely by placing the premultiplication nucleus at the head of the viticultural channel as a guarantee of ensuring the biological traceability and retraceability of the certified propagation material. Also, in the nucleus hothouse, the ameliorator transfers the results of clone selection, sanitary and creation of new genotypes activity which can be finalized by homologation. These stipulations which should be controlled and respected during the maintenance period with a view to prevent the biological degradation and the reinfection with pathogens of the propagating material, are obligatory during premultiplication and transfer period in the nursery.

  4. Neutrino-nucleus reactions and their role for supernova dynamics and nucleosynthesis

    CERN Document Server

    Balasi, K G; Martínez-Pinedo, G

    2015-01-01

    The description of nuclear reactions induced by supernova neutrinos has witnessed significant progress during the recent years. At the energies and momentum transfers relevant for supernova neutrinos neutrino-nucleus cross sections are dominated by allowed transitions, however, often with non-negligible contributions from (first) forbidden transitions. For several nuclei allowed Gamow-Teller strength distributions could be derived from charge-exchange reactions and from inelastic electron scattering data. Importantly the diagonalization shell model has been proven to accurately describe these data and hence became the appropriate tool to calculate the allowed contributions to neutrino-nucleus cross sections for supernova neutrinos. Higher multipole contributions are usually calculated within the framework of the Quasiparticle Random Phase Approximation, which describes the total strength and the position of the giant resonances quite well. This manuscript reviews the recent progress achieved in calculating su...

  5. The Arcuate Sign: A Marker of Potential Knee Dislocation? A Report of Two Cases

    OpenAIRE

    Crimmins, Jason T.; Wissman, Robert D.

    2015-01-01

    The arcuate sign is a well described finding of fibular head avulsion at the insertion site of the arcuate complex. It has been associated with posterolateral corner knee injury and resulting instability. The authors report two patients presenting with the arcuate sign following knee dislocation, which has not been previously described. As unrecognized spontaneously reduced knee dislocation often results in significant morbidity, the authors propose that the arcuate sign should raise clinical...

  6. Role of G-proteins in the effects of leptin on pedunculopontine nucleus (PPN) neurons

    OpenAIRE

    Beck, Paige; Mahaffey, Susan; Urbano, Francisco J.; Garcia-Rill, Edgar

    2013-01-01

    The pedunculopontine nucleus (PPN), the cholinergic arm of the reticular activating system, regulates waking and rapid eye movement (REM) sleep. Here, we demonstrate immunohistochemical labeling of the leptin receptor signaling isoform in PPN neurons, and investigated the effects of G-protein modulation and the leptin triple antagonist (TA) on the action of leptin in the PPN. Whole-cell patch clamp recordings were performed in rat brainstem slices from 9–17 day old pups. Previous results show...

  7. The role of the dorsal raphé nucleus in reward-seeking behavior

    OpenAIRE

    Kae eNakamura

    2013-01-01

    Pharmacological experiments have shown that the modulation of brain serotonin levels has a strong impact on value-based decision making. Anatomical and physiological evidence also revealed that the dorsal raphé nucleus (DRN), a major source of serotonin, and the dopamine system receive common inputs from brain regions associated with appetitive and aversive information processing. The serotonin and dopamine systems also have reciprocal functional influences on each other. However, the sp...

  8. A Primary Role for Nucleus Accumbens and Related Limbic Network in Vocal Tics.

    Science.gov (United States)

    McCairn, Kevin W; Nagai, Yuji; Hori, Yukiko; Ninomiya, Taihei; Kikuchi, Erika; Lee, Ju-Young; Suhara, Tetsuya; Iriki, Atsushi; Minamimoto, Takafumi; Takada, Masahiko; Isoda, Masaki; Matsumoto, Masayuki

    2016-01-20

    Inappropriate vocal expressions, e.g., vocal tics in Tourette syndrome, severely impact quality of life. Neural mechanisms underlying vocal tics remain unexplored because no established animal model representing the condition exists. We report that unilateral disinhibition of the nucleus accumbens (NAc) generates vocal tics in monkeys. Whole-brain PET imaging identified prominent, bilateral limbic cortico-subcortical activation. Local field potentials (LFPs) developed abnormal spikes in the NAc and the anterior cingulate cortex (ACC). Vocalization could occur without obvious LFP spikes, however, when phase-phase coupling of alpha oscillations were accentuated between the NAc, ACC, and the primary motor cortex. These findings contrasted with myoclonic motor tics induced by disinhibition of the dorsolateral putamen, where PET activity was confined to the ipsilateral sensorimotor system and LFP spikes always preceded motor tics. We propose that vocal tics emerge as a consequence of dysrhythmic alpha coupling between critical nodes in the limbic and motor networks. VIDEO ABSTRACT.

  9. Role of G-proteins in the effects of leptin on pedunculopontine nucleus neurons.

    Science.gov (United States)

    Beck, Paige; Mahaffey, Susan; Urbano, Francisco J; Garcia-Rill, Edgar

    2013-09-01

    The pedunculopontine nucleus (PPN), the cholinergic arm of the reticular activating system, regulates waking and rapid eye movement sleep. Here, we demonstrate immunohistochemical labeling of the leptin receptor signaling isoform in PPN neurons, and investigated the effects of G-protein modulation and the leptin triple antagonist (TA) on the action of leptin in the PPN. Whole-cell patch clamp recordings were performed in rat brainstem slices from 9 to 17 day old pups. Previous results showed that leptin caused a partial blockade of sodium (I(Na)) and h-current (I(H)) in PPN neurons. TA (100 nM) reduced the blockade of I(Na) (~ 50% reduction) and I(H) (~ 93% reduction) caused by leptin. Intracellular guanosine 5'-[β-thio]diphosphate trilithium salt (a G-protein inhibitor) significantly reduced the effect of leptin on I(Na) (~ 60% reduction) but not on I(H) (~ 25% reduction). Intracellular GTPγS (a G-protein activator) reduced the effect of leptin on both I(Na) (~ 80% reduction) and I(H) (~ 90% reduction). These results suggest that the effects of leptin on the intrinsic properties of PPN neurons are leptin receptor- and G-protein dependent. We also found that leptin enhanced NMDA receptor-mediated responses in single neurons and in the PPN population as a whole, an effect blocked by TA. These experiments further strengthen the association between leptin dysregulation and sleep disturbances. Beck et al. investigated the effects of leptin on the intrinsic properties of neurons from the pedunculopontine nucleus (PPN). Leptin reduced the amplitude of voltage-gated sodium (I(Na)) and hyperpolarization-activated cyclic nucleotide-gated HCN (I(H)) channels. These effects were antagonized by a leptin receptor (OB-R) antagonist and by the G-protein antagonist GDPβ. PMID:23692342

  10. Research progress of arcuate fasciculus with diffusion tensor tractography

    OpenAIRE

    Geng, Jie-feng; Chen, Xiao-Lei; XU Bai-nan

    2015-01-01

    Arcuate fasciculus (AF) is a crucial part of human language network. Diffusion tensor tractography (DTT) is the most common method for reconstruction of white matter fibers in vivo. DTT is widely applied in both basic researches on the anatomical structure and functions of AF and clinical studies on AF navigation. However, the validity of AF with DTT needs further investigation in the future. DOI: 10.3969/j.issn.1672-6731.2015.04.015

  11. Research progress of arcuate fasciculus with diffusion tensor tractography

    Directory of Open Access Journals (Sweden)

    Jie-feng GENG

    2015-04-01

    Full Text Available Arcuate fasciculus (AF is a crucial part of human language network. Diffusion tensor tractography (DTT is the most common method for reconstruction of white matter fibers in vivo. DTT is widely applied in both basic researches on the anatomical structure and functions of AF and clinical studies on AF navigation. However, the validity of AF with DTT needs further investigation in the future. DOI: 10.3969/j.issn.1672-6731.2015.04.015

  12. Saturation of Nuclear Matter and Roles of Many-Body Forces: nuclear matter in neutron stars probed by nucleus-nucleus scattering

    CERN Document Server

    Sakuragi, Y

    2016-01-01

    Yoichiro Nambu put a great foot print in nuclear physics in the era of its fundamental developments including his pioneering insight into essential ingredients of repulsive core of nuclear force and its relation to the saturation of nuclear matter. The present review article focuses onto recent developments of the interaction models between colliding nuclei in terms of Brueckner's G-matrix theory staring from realistic nuclear forces and the saturation property of symmetric nuclear matter as well as neutron-star matter. A recently proposed unique scenario of extracting the saturation property of nuclear matter and stiffness of neutron stars through the analysis of nucleus-nucleus elastic scattering in laboratories is presented in some detail.

  13. Inferior olivary nucleus involvement in pediatric neurodegenerative disorders: does it play a role in neuroimaging pattern-recognition approach?

    Science.gov (United States)

    Mirabelli-Badenier, Marisol; Morana, Giovanni; Bruno, Claudio; Di Rocco, Maja; Striano, Pasaquale; De Grandis, Eusa; Veneselli, Edvige; Rossi, Andrea; Biancheri, Roberta

    2015-04-01

    The diagnostic work up of neurometabolic/degenerative disorders is complex. In such context, identification of neuroradiological features suggestive of specific diagnoses is useful to prompt further diagnostic tests. Involvement of the inferior olivary nucleus (ION) has been reported in several pathologic conditions, either as a primary manifestation of disease or secondary to hypertrophic olivary degeneration (HOD). In this study, we analyzed a cohort of 95 children with different neurometabolic/degenerative diseases involving the brainstem and cerebellum, with the aim to evaluate whether ION involvement plays a role in a neuroimaging-based pattern-recognition approach. A total of 13 patients (13.7%) showed bilateral high-signal intensity and enlargement of the ION on T2-weighted images, while 16 (16.8%) had ION T2-hyperintensity without olivary nucleus enlargement. Our study demonstrates that ION involvement is not rare in children with neurometabolic/degenerative disorders. Two main neuroradiological patterns, that is, "T2-hyperintense signal" and "T2-hyperintense signal with enlargement" are found. These patterns can be related to different etiologies, and do not suggest specific diagnoses. Primary ION lesion can be characterized by olivary swelling, and the differentiation from typical secondary HOD may be difficult. PMID:25686202

  14. Dorsal raphe nucleus acetylcholine-mediated neurotransmission modulates post-ictal antinociception: The role of muscarinic and nicotinic cholinergic receptors.

    Science.gov (United States)

    de Oliveira, Rithiele Cristina; de Oliveira, Ricardo; Biagioni, Audrey Francisco; Falconi-Sobrinho, Luiz Luciano; Coimbra, Norberto Cysne

    2016-01-15

    The dorsal raphe nucleus (DRN) is a key structure of the endogenous pain inhibitory system. Although the DRN is rich in serotoninergic neurons, cholinergic neurons are also found in that nucleus. Both ictal and inter-ictal states are followed by post-ictal analgesia. The present study investigated the role of cholinergic mechanisms in postictal antinociceptive processes using microinjections of atropine and mecamylamine, muscarinic and nicotinic cholinergic receptor antagonists, respectively, in the DRN of rats. Intraperitoneal injection of pentylenetetrazole (PTZ) (at 64mg/kg) caused tonic and tonic-clonic seizures. The convulsive motor reactions were followed by an increase in pain thresholds, a phenomenon known as post-ictal analgesia. Pre-treatment of the DRN with atropine or mecamylamine at 1µg, 3µg and 5µg/0.2µL decreased the post-ictal antinociceptive phenomenon. The present results showed that the post-ictal analgesia was mediated by muscarinic and nicotinic cholinergic receptors in the DRN, a structure crucially involved in the neural network that organises post-ictal hypoalgesia. PMID:26620541

  15. Functional role of Barrington's nucleus in the micturition reflex: relevance in the surgical treatment of Parkinson's disease.

    Science.gov (United States)

    Blanco, L; Ros, C M; Tarragón, E; Fernández-Villalba, E; Herrero, M T

    2014-04-25

    The pontine micturition center or Barrington's nucleus (BN) - besides regulating micturition - co-regulates the activity of other pelvic viscera such as the colon and genitals. At present, this issue is gaining particular importance due to: (i) recent findings of α-synuclein in BN, (ii) known urinary dysfunction in parkinsonian patients (part of the so-called non-motor symptoms), other patients with dementia and as in very old individuals; and (iii) its proximity to the pedunculopontine nucleus, a surgical target in deep brain stimulation for Parkinson's disease (PD). The structural and functional organization of the micturition reflex comprises a coordinating action of somatic motor activity with both divisions of the autonomic nervous system, modulated by trunk encephalic and cortical centers that involve the BN as locus coeruleus and periaqueductal gray matter, among other trunk encephalic structures. The involvement of dopaminergic activity (physiologic inhibition of the micturition reflex mediated by dopaminergic D1 activity) that diminishes in Parkinsonism and leads to overactivity of the micturition reflex is also well known. In this review, the integrating role of the BN in the context of vesical and gastrointestinal behavior is revisited, and the principal morpho-functional findings that associate dysfunction with the urinary disorders that appear during the pre-motor stages of PD are summarized.

  16. Phosphorylation of CaMKII in the rat dorsal raphe nucleus plays an important role in sleep-wake regulation.

    Science.gov (United States)

    Cui, Su-Ying; Li, Sheng-Jie; Cui, Xiang-Yu; Zhang, Xue-Qiong; Yu, Bin; Sheng, Zhao-Fu; Huang, Yuan-Li; Cao, Qing; Xu, Ya-Ping; Lin, Zhi-Ge; Yang, Guang; Song, Jin-Zhi; Ding, Hui; Wang, Zi-Jun; Zhang, Yong-He

    2016-02-01

    The Ca(2+) modulation in the dorsal raphe nucleus (DRN) plays an important role in sleep-wake regulation. Calmodulin-dependent kinase II (CaMKII) is an important signal-transducing molecule that is activated by Ca(2+) . This study investigated the effects of intracellular Ca(2+) /CaMKII signaling in the DRN on sleep-wake states in rats. Maximum and minimum CaMKII phosphorylation was detected at Zeitgeber time 21 (ZT 21; wakefulness state) and ZT 3 (sleep state), respectively, across the light-dark rhythm in the DRN in rats. Six-hour sleep deprivation significantly reduced CaMKII phosphorylation in the DRN. Microinjection of the CAMKII activation inhibitor KN-93 (5 or 10 nmol) into the DRN suppressed wakefulness and enhanced rapid-eye-movement sleep (REMS) and non-REM sleep (NREMS). Application of a high dose of KN-93 (10 nmol) increased slow-wave sleep (SWS) time, SWS bouts, the mean duration of SWS, the percentage of SWS relative to total sleep, and delta power density during NREMS. Microinjection of CaCl2 (50 nmol) in the DRN increased CaMKII phosphorylation and decreased NREMS, SWS, and REMS. KN-93 abolished the inhibitory effects of CaCl2 on NREMS, SWS, and REMS. These data indicate a novel wake-promoting and sleep-suppressing role for the Ca(2+) /CaMKII signaling pathway in DRN neurons. We propose that the intracellular Ca(2+) /CaMKII signaling in the dorsal raphe nucleus (DRN) plays wake-promoting and sleep-suppressing role in rats. Intra-DRN application of KN-93 (CaMKII activation inhibitor) suppressed wakefulness and enhanced rapid-eye-movement sleep (REMS) and non-REMS (NREMS). Intra-DRN application of CaCl2 attenuated REMS and NREMS. We think these findings should provide a novel cellular and molecular mechanism of sleep-wake regulation. PMID:26558357

  17. The role of the dorsal raphé nucleus in reward-seeking behavior

    Directory of Open Access Journals (Sweden)

    Kae eNakamura

    2013-08-01

    Full Text Available Pharmacological experiments have shown that the modulation of brain serotonin levels has a strong impact on value-based decision making. Anatomical and physiological evidence also revealed that the dorsal raphé nucleus (DRN, a major source of serotonin, and the dopamine system receive common inputs from brain regions associated with appetitive and aversive information processing. The serotonin and dopamine systems also have reciprocal functional influences on each other. However, the specific mechanism by which serotonin affects value-based decision making is not clear.To understand the information carried by the DRN for reward-seeking behavior, we measured single neuron activity in the primate DRN during the performance of saccade tasks to obtain different amounts of a reward. We found that DRN neuronal activity was characterized by tonic modulation that was altered by the expected and received reward value. Consistent reward-dependent modulation across different task periods suggested that DRN activity kept track of the reward value throughout a trial. The DRN was also characterized by modulation of its activity in the opposite direction by different neuronal subgroups, one firing strongly for the prediction and receipt of large rewards, with the other firing strongly for small rewards. Conversely, putative dopamine neurons showed positive phasic responses to reward-indicating cues and the receipt of an unexpected reward amount, which supports the reward prediction error signal hypothesis of dopamine.I suggest that the tonic reward monitoring signal of the DRN, possibly together with its interaction with the dopamine system, reports a continuous level of motivation throughout the performance of a task. Such a signal may provide reward context information to the targets of DRN projections, where it may be integrated further with incoming motivationally salient information.

  18. Median arcuate ligament syndrome: a nonvascular, vascular diagnosis.

    Science.gov (United States)

    Skeik, Nedaa; Cooper, Leslie T; Duncan, Audra A; Jabr, Fadi I

    2011-07-01

    Median arcuate ligament syndrome (MALS) is often diagnosed when idiopathic, episodic abdominal pain is associated with dynamic compression of the proximal celiac artery by fibers of the median arcuate ligament. The character of the abdominal pain is often postprandial and associated with gradual weight loss from poor food intake, suggestive of chronic mesenteric ischemia. However, the pathognomonic imaging feature of dynamic, ostial celiac artery compression with expiration does not consistently predict clinical improvement from revascularization. Proposed but unproven pathophysiological mechanisms include neurogenic pain from compression of the splanchnic nerve plexus and intermittent ischemia from compression of the celiac artery. Alterations in blood flow and ganglion compression are both associated with delayed gastric emptying, another physiological correlate of the clinical syndrome. Published reports describe a variable response to revascularization and nerve plexus resection suggest a need for translational research to better characterize this poorly understood clinical entity. We illustrate the current gaps in our knowledge of MALS with the case of a 51-year-old woman with a 4-year history of chronic abdominal pain who responded to a combination of ganglion resection and celiac artery reconstruction. PMID:21536596

  19. Arcuate AgRP neurons and the regulation of energy balance

    Directory of Open Access Journals (Sweden)

    Céline eCansell

    2012-12-01

    Full Text Available The arcuate nucleus of the hypothalamus contains at least two crucial populations of neurons that continuously monitor signals reflecting energy status and promote the appropriate behavioral and metabolic responses to changes in energy demand. Neurons making pro-opiomelanocortin (POMC decrease food intake and increase energy expenditure through activation of G protein-coupled receptors melanocortin receptors (MCR via the release of a-melanocyte stimulating hormone. A prevailing idea until recently was that the neighboring neurons expressing the orexigenic neuropeptides, agouti-related protein (AgRP and neuropeptide Y (NPY (AgRP neurons increased feeding by opposing the anorexigenic actions of the POMC neurons. AgRP neurons activation but not POMC neurons inhibition was recently demonstrated to be necessary and sufficient to promote feeding. AgRP expressing axons were identified in mesolimbic, midbrain and pontine structure where they regulate feeding but also feeding-independent functions such as reward or peripheral nutrient partitioning. Post-synaptic Gamma aminobutyric acid (GABA, lasting in a timeline similar to neuromodulation, was identified as the core mechanism by which hunger-activated neurons regulate feeding and non-food related processes in a melanocortin independent manner.

  20. Peroxisome Proliferator-Activated Receptor γ Controls Ingestive Behavior, Agouti-Related Protein, and Neuropeptide Y mRNA in the Arcuate Hypothalamus

    Science.gov (United States)

    Garretson, John T.; Teubner, Brett J.W.; Grove, Kevin L.; Vazdarjanova, Almira; Ryu, Vitaly

    2015-01-01

    Peroxisome proliferator-activated receptor γ (PPARγ) is clinically targeted for type II diabetes treatment; however, rosiglitazone (ROSI), a PPARγ agonist, increases food intake and body/fat mass as side-effects. Mechanisms for these effects and the role of PPARγ in feeding are not understood. Therefore, we tested this role in Siberian hamsters, a model of human energy balance, and C57BL/6 mice. We tested the following: (1) how ROSI and/or GW9662 (2-chloro-5-nitro-N-phenylbenzamide; PPARγ antagonist) injected intraperitoneally or into the third ventricle (3V) affected Siberian hamster feeding behaviors; (2) whether food deprivation (FD) co-increases agouti-related protein (AgRP) and PPARγ mRNA expression in Siberian hamsters and mice; (3) whether intraperitoneally administered ROSI increases AgRP and NPY in ad libitum-fed animals; (4) whether intraperitoneally administered PPARγ antagonism blocks FD-induced increases in AgRP and NPY; and finally, (5) whether intraperitoneally administered PPARγ modulation affects plasma ghrelin. Third ventricular and intraperitoneally administered ROSI increased food hoarding and intake for 7 d, an effect attenuated by 3V GW9662, and also prevented (intraperitoneal) FD-induced feeding. FD hamsters and mice increased AgRP within the arcuate hypothalamic nucleus with concomitant increases in PPARγ exclusively within AgRP/NPY neurons. ROSI increased AgRP and NPY similarly to FD, and GW9662 prevented FD-induced increases in AgRP and NPY in both species. Neither ROSI nor GW9662 affected plasma ghrelin. Thus, we demonstrated that PPARγ activation is sufficient to trigger food hoarding/intake, increase AgRP/NPY, and possibly is necessary for FD-induced increases in feeding and AgRP/NPY. These findings provide initial evidence that FD-induced increases in AgRP/NPY may be a direct PPARγ-dependent process that controls ingestive behaviors. PMID:25788674

  1. Fast synchronous oscillations of firing rate in cultured rat suprachiasmatic nucleus neurons: possible role in circadian synchronization in the intact nucleus.

    Science.gov (United States)

    Kononenko, Nikolai I; Honma, Sato; Honma, Ken-Ichi

    2013-03-01

    The coherent circadian rhythm of the brain's master circadian pacemaker, the suprachiasmatic nucleus (SCN), is a result of synchronization of electrical activity of many SCN neurons possessing their own circadian oscillators. However, how the activity of these neurons is synchronized is not precisely known. By plotting the electrical firing rates of dispersed rat SCN neurons in multi-electrode array dishes with 20-s averaging of action-potential activity, we have investigated a novel phenomenon: fast (relative to the circadian cycle) oscillations of firing rate (FOFR) with duration of bursts ∼10min and interburst interval varying in a range from 20 to 60min in different cells, remaining nevertheless rather regular in individual cells. In many cases, separate neurons in distant parts of the 1mm recording area of an array exhibited correlated FOFR. FOFR of individual cells were positively or negatively correlated with those of other cells in a functioning neural network. Intriguingly, in occasional neuron pairs, transformation of their irregular firing to circadian peaks was accompanied by appearance of FOFR and an increase in the magnitude of firing correlation. We hypothesize that this FOFR observed in cultured SCN neurons contribute to synchronization of the circadian rhythm in the intact SCN.

  2. A potential role for the paraventricular nucleus of the thalamus in mediating individual variation in Pavlovian conditioned responses

    Directory of Open Access Journals (Sweden)

    Joshua Lewis Haight

    2014-03-01

    Full Text Available There is ample evidence to suggest that the paraventricular nucleus of the thalamus (PVT mediates cue-reward learning, especially as it relates to drug-seeking behavior. However, its exact role in these complex processes remains unknown. Here we will present and discuss data from our own laboratory which suggests that the PVT plays a role in multiple forms of stimulus-reward learning, and does so via distinct neurobiological systems. Using an animal model that captures individual variation in response to reward-associated cues, we are able to parse the incentive from the predictive properties of reward cues and to elucidate the neural circuitry underlying these different forms of cue-reward learning. When rats are exposed to a classical Pavlovian conditioning paradigm, wherein a cue predicts food reward, some rats, termed sign-trackers, approach and manipulate the cue upon its presentation. This behavior is indicative of attributing incentive salience to the cue. That is, the cue gains excessive control over behavior for sign-trackers. In contrast, other rats, termed goal-trackers, treat the cue as a mere predictor, and upon its presentation go to the location of reward delivery. Based on our own data utilizing this model, we hypothesize that the PVT represents a common node, but differentially regulates the sign- vs. goal-tracking response. We postulate that the PVT regulates sign-tracking behavior, or the attribution of incentive salience, via subcortical, dopamine-dependent mechanisms. In contrast, we propose that goal-tracking behavior, or the attribution of predictive value, is the product of top-down glutamatergic processing between the prelimbic cortex and the PVT. Together, data from our laboratory and others support a role for the PVT in cue-motivated behaviors and suggest that it may be an important locus within the neural circuitry that goes awry in addiction and related disorders.

  3. Opposing roles for the nucleus accumbens core and shell in cue-induced reinstatement of food-seeking behavior.

    Science.gov (United States)

    Floresco, S B; McLaughlin, R J; Haluk, D M

    2008-06-26

    Reinstatement of previously extinguished instrumental responding for drug-related cues has been used as an animal model for relapse of drug abuse, and is differentially affected by inactivation of the core and shell subregions of the nucleus accumbens (NAc). To compare the roles of these subregions in reinstatement induced by cues associated with natural and drug rewards, the present study assessed the effects of inactivation of the NAc core and shell on cue-induced reinstatement of food-seeking behavior. Rats acquired a lever pressing response for food reward paired with a light/tone conditioned stimulus (CS). They were then subjected to extinction, where both food and the CS were withheld. Reinstatement of responding was measured during response-contingent presentations of the CS. Following saline infusions into the NAc core or shell, rats displayed a significant increase in lever pressing during reinstatement sessions. Inactivation of the core, induced by infusion of GABA agonists muscimol and baclofen, attenuated responding for the CS, but did not affect pavlovian approach toward the food receptacle. In contrast, inactivation of the shell had the opposite effect, potentiating responding relative to vehicle treatments. These data suggest that the NAc core and shell play opposing, yet complementary roles in mediating the influence that food-associated conditioned stimuli exert over behavior. The core enables reward-related stimuli to bias the direction and vigor of instrumental responding. In contrast, the shell facilitates alterations in behavior in response to changes in the incentive value of conditioned stimuli. The fact that the NAc core appears to play a similar role in cue-induced reinstatement induced by both natural and drug rewards suggests that this region of the ventral striatum may be a final common pathway through which both drug- and food-associated stimuli may influence the direction and magnitude of ongoing behavior. PMID:18479836

  4. THE ROLE OF RED NUCLEUS IN THE MODULATION OF SPINAL NOCICEPTIVE TRANSMISSION AND IN NOCICEPTION ELICITED BY MUSCLE SPINDLE AFFERENTS

    Institute of Scientific and Technical Information of China (English)

    唐斌; 樊小力; 吴苏娣

    2003-01-01

    Objective To analyse the antinociceptive effect of red nucleus (RN) and its role in the antinociceptive effect of muscle spindle afferents. Methods The single units of RN or wide dynamic range (WDR) neuron in the spinal cord dorsal horn were extracelluarly recorded. The effects of RN stimulation on nociceptive responses (C-fibers-evoked responses, C-responses) of WDR neurons were observed. The influence of muscle spindle afferents elicited by intravenous administration of succinylcholine (Sch) on the spontaneous discharge of RN neurons and on C-responses of WDR neurons were observed. The effect of muscle spindle afferents on C-responses of WDR neurons after unilateral lesions of RN was also observed. Results Electrical stimulation of the RN produced a significantly inhibitory effect on the nociceptive responses of WDR neurons. RN neurons were excited by muscle spindle afferents. Muscle spindle afferents significantly inhibited C-response of WDR neurons and this inhibitory effect was reduced by lesions of RN. Conclusion RN neurons have a significant antinociceptive effect and might be involved in the antinociceptive effects elicited by muscle spindle afferents.

  5. Lateral hypothalamus, nucleus accumbens, and ventral pallidum roles in eating and hunger: interactions between homeostatic and reward circuitry

    Directory of Open Access Journals (Sweden)

    Daniel Charles Castro

    2015-06-01

    Full Text Available The study of the neural bases of eating behavior, hunger, and reward has consistently implicated the lateral hypothalamus (LH and its interactions with mesocorticolimbic circuitry, such as mesolimbic dopamine projections to nucleus accumbens (NAc and ventral pallidum (VP, in controlling motivation to eat. The NAc and VP play special roles in mediating the hedonic impact (‘liking’ and motivational incentive salience (‘wanting’ of food rewards, and their interactions with LH help permit regulatory hunger/satiety modulation of food motivation and reward. Here, we review some progress that has been made regarding this circuitry and its functions: the identification of localized anatomical hedonic hotspots within NAc and VP for enhancing hedonic impact; interactions of NAc/VP hedonic hotspots with specific LH signals such as orexin; an anterior-posterior gradient of sites in NAc shell for producing intense appetitive eating versus intense fearful reactions; and anatomically distributed appetitive functions of dopamine and mu opioid signals in NAc shell and related structures. Such findings help improve our understanding of NAc, VP, and LH interactions in mediating affective and motivation functions, including ‘liking’ and ‘wanting’ for food rewards.

  6. Role of the lateral paragigantocellular nucleus in the network of paradoxical (REM sleep: an electrophysiological and anatomical study in the rat.

    Directory of Open Access Journals (Sweden)

    Chrystelle Sirieix

    Full Text Available The lateral paragigantocellular nucleus (LPGi is located in the ventrolateral medulla and is known as a sympathoexcitatory area involved in the control of blood pressure. In recent experiments, we showed that the LPGi contains a large number of neurons activated during PS hypersomnia following a selective deprivation. Among these neurons, more than two-thirds are GABAergic and more than one fourth send efferent fibers to the wake-active locus coeruleus nucleus. To get more insight into the role of the LPGi in PS regulation, we combined an electrophysiological and anatomical approach in the rat, using extracellular recordings in the head-restrained model and injections of tracers followed by the immunohistochemical detection of Fos in control, PS-deprived and PS-recovery animals. With the head-restrained preparation, we showed that the LPGi contains neurons specifically active during PS (PS-On neurons, neurons inactive during PS (PS-Off neurons and neurons indifferent to the sleep-waking cycle. After injection of CTb in the facial nucleus, the neurons of which are hyperpolarized during PS, the largest population of Fos/CTb neurons visualized in the medulla in the PS-recovery condition was observed in the LPGi. After injection of CTb in the LPGi itself and PS-recovery, the nucleus containing the highest number of Fos/CTb neurons, moreover bilaterally, was the sublaterodorsal nucleus (SLD. The SLD is known as the pontine executive PS area and triggers PS through glutamatergic neurons. We propose that, during PS, the LPGi is strongly excited by the SLD and hyperpolarizes the motoneurons of the facial nucleus in addition to local and locus coeruleus PS-Off neurons, and by this means contributes to PS genesis.

  7. Role of mitogen-activated protein kinases in the regulation of paraventricular nucleus to gastric ischemia-reperfusion injuries

    Institute of Scientific and Technical Information of China (English)

    LI Li; ZHANG Yong-mei; QIAO Wei-li; ZHANG Jian-fu; WANG Lin

    2007-01-01

    Background We investigated the role in electrical stimulations of paraventricular nucleus (PVN) on gastric mucosal cells and the activity of mitogen-activated protein kinases (MAPKs) family members induced by gastric ischemia-repertusion (Gl-R). And we elucidated the molecular mechanisms of the protection of PVN from GI-R injuries.Methods Sprague-Dawley rats were divided randomly into 4 groups: Group Ⅰ, the sham-operated GI-R control group;Group Ⅱ, the sham-operated electrical stimulations to PVN + sham-operated GI-R control group; Group Ⅲ, the GI-R group; and Group Ⅳ, the electrical stimulations to PVN + GI-R group. In all of the experiments, the PVN was stimulated prior to the induction of GI-R. The GI-R model was established by clamping the celiac artery for 30 minutes to induce ischemia and then was released to allow reperfusion for 30 minutes, 1 hour, 3 hours and 6 hours, respectively. The gastric mucosal cellular apoptosis, proliferation, and the expression and activity of MAPKs protein were observed by immunohistochemistry and Western blotting, respectively.Results Compared with the GI-R group, the application of electrical stimulations in the PVN significantly depressed gastric mucosal cellular apoptosis and enhanced gastric mucosal cellular proliferation following the 30-minute, 1-hour and 3-hour intervals of reperfusion; it also promoted the activation of p-ERK during the early phase of reperfusion but inhibited the activation of p-JNK1/2 and p-p38 following the 30-minute, 1-hour and 3-hour intervals of reperfusion.Conclusions The protection of PVN against GI-R injuries may attribute to the inhibition of apoptosis and the promotion of the proliferation of gastric mucosal cells during GI-R. This protective effect is mediated by activating the ERK pathway and depressing the JNK, p38 MAPK pathways of the gastric mucosal cells.

  8. Role of the thalamic nucleus reuniens in mediating interactions between the hippocampus and medial prefrontal cortex during spatial working memory

    Directory of Open Access Journals (Sweden)

    Amy L Griffin

    2015-03-01

    Full Text Available Despite decades of research, the neural mechanisms of spatial working memory remain poorly understood. Although the dorsal hippocampus is known to be critical for memory-guided behavior, experimental evidence suggests that spatial working memory depends not only on the hippocampus itself, but also on the circuit comprised of the hippocampus and the medial prefrontal cortex (mPFC. Disruption of hippocampal-mPFC interactions may result in failed transfer of spatial and contextual information processed by the hippocampus to the circuitry in mPFC responsible for decision making and goal-directed behavior. Oscillatory synchrony between the hippocampus and mPFC has been shown to increase in tasks with high spatial working memory demand. However, the mechanisms and circuitry supporting hippocampal-mPFC interactions during these tasks is unknown. The midline thalamic nucleus reuniens (RE is reciprocally connected to both the hippocampus and the mPFC and has been shown to be critical for a variety of working memory tasks. Therefore, it is likely that hippocampal-mPFC oscillatory synchrony is modulated by RE activity. This article will review the anatomical connections between the hippocampus, mPFC and RE along with the behavioral studies that have investigated the effects of RE disruption on working memory task performance. The article will conclude with suggestions for future directions aimed at identifying the specific role of the RE in regulating functional interactions between the hippocampus and the PFC and investigating the degree to which these interactions contribute to spatial working memory.

  9. Fear extinction can be made state-dependent on peripheral epinephrine: role of norepinephrine in the nucleus tractus solitarius.

    Science.gov (United States)

    Rosa, Jessica; Myskiw, Jociane C; Furini, Cristiane R G; Sapiras, Gerson G; Izquierdo, Ivan

    2014-09-01

    We investigate whether the extinction of inhibitory avoidance (IA) learning can be subjected to endogenous state-dependence with systemic injections of epinephrine (E), and whether endogenous norepinephrine (NE) and the nucleus tractus solitarius (NTS)→locus coeruleus→hippocampus/amygdala (HIPP/BLA) pathway participate in this. Rats trained in IA were submitted to two sessions of extinction 24 h apart: In the first, the animals were submitted to a training session of extinction, and in the second they were tested for the retention of extinction. Saline or E were given i.p. immediately after the extinction training (post-extinction training injections) and/or 6 min before the extinction test (pre-extinction test). Post-extinction training E (50 or 100 μg/kg) induced a poor retrieval of extinction in the test session of this task unless an additional E injection (50 μg/kg) was given prior to the extinction test. This suggested state-dependence. Muscimol (0.01 μg/side) microinfused into the NTS prior to the extinction test session blocked E-induced state-dependence. Norepinephrine (NE, 1 μg/side) infused bilaterally into NTS restores the extinction impairment caused by post-extinction training i.p. E. In animals with bilateral NTS blockade induced by muscimol, NE (1 μg/side) given prior to the extinction test into the CA1 region of the dorsal hippocampus or into the basolateral amygdala restored the normal extinction levels that had been impaired by muscimol. These results suggest a role for the NTS→locus coeruleus→HIPP/BLA pathway in the retrieval of extinction, as it has been shown to have in the consolidation of inhibitory avoidance and of object recognition learning.

  10. Critical role of cholinergic transmission from the laterodorsal tegmental nucleus to the ventral tegmental area in cocaine-induced place preference

    OpenAIRE

    Shinohara, Fumiya; Kihara, Yukari; Ide, Soichiro; Minami, Masabumi; Kaneda, Katsuyuki

    2014-01-01

    Conditioned place preference (CPP) is widely used to investigate the rewarding properties of cocaine. Various brain regions and neurotransmitters are involved in developing cocaine CPP. However, the contribution of cholinergic transmission in the ventral tegmental area (VTA) to cocaine CPP remains largely unexplored. Here, we examined the role of cholinergic input arising from the laterodorsal tegmental nucleus (LDT) to the VTA in the acquisition and expression of cocaine CPP in rats. Intra-L...

  11. The role of D-serine as co-agonist of NMDA receptors in the nucleus accumbens: relevance to cocaine addiction

    OpenAIRE

    D’Ascenzo, Marcello; Podda, Maria Vittoria; Grassi, Claudio

    2014-01-01

    Cocaine addiction is characterized by compulsive drug use despite adverse consequences and high rate of relapse during periods of abstinence. Increasing consensus suggests that addiction to drugs of abuse usurps learning and memory mechanisms normally related to natural rewards, ultimately producing long-lasting neuroadaptations in the mesocorticolimbic system. This system, formed in part by the ventral tegmental area and nucleus accumbens (NAc), has a central role in the development and expr...

  12. Dopamine D1 and D2 receptor immunoreactivities in the arcuate-median eminence complex and their link to the tubero-infundibular dopamine neurons

    Directory of Open Access Journals (Sweden)

    W. Romero-Fernandez

    2014-07-01

    Full Text Available Dopamine D1 and D2 receptor immunohistochemistry and Golgi techniques were used to study the structure of the adult rat arcuate-median eminence complex, and determine the distribution of the dopamine D1 and D2 receptor immunoreactivities therein, particularly in relation to the tubero-infundibular dopamine neurons. Punctate dopamine D1 and D2 receptor immunoreactivities, likely located on nerve terminals, were enriched in the lateral palisade zone built up of nerve terminals, while the densities were low to modest in the medial palisade zone. A codistribution of dopamine D1 receptor or dopamine D2 receptor immunoreactive puncta with tyrosine hydroxylase immunoreactive nerve terminals was demonstrated in the external layer. Dopamine D1 receptor but not dopamine D2 receptor immnunoreactivites nerve cell bodies were found in the ventromedial part of the arcuate nucleus and in the lateral part of the internal layer of the median eminence forming a continuous cell mass presumably representing neuropeptide Y immunoreactive nerve cell bodies. The major arcuate dopamine/ tyrosine hydroxylase nerve cell group was found in the dorsomedial part. A large number of tyrosine hydroxylase immunoreactive nerve cell bodies in this region demonstrated punctate dopamine D1 receptor immunoreactivity but only a few presented dopamine D2 receptor immunoreactivity which were mainly found in a substantial number of tyrosine hydroxylase cell bodies of the ventral periventricular hypothalamic nucleus, also belonging to the tubero-infundibular dopamine neurons. Structural evidence for projections of the arcuate nerve cells into the median eminence was also obtained. Distal axons formed horizontal axons in the internal layer issuing a variable number of collaterals classified into single or multiple strands located in the external layer increasing our understanding of the dopamine nerve terminal networks in this region.  Dopamine D1 and D2 receptors may therefore directly

  13. Curvature range measurements of the arcuate fasciculus using diffusion tensor tractography

    Institute of Scientific and Technical Information of China (English)

    Dong Hoon Lee; Cheol Pyo Hong; Yong Hyun Kwon; Yoon Tae Hwang; Joong Hwi Kim; Ji Won Park

    2013-01-01

    Because Broca's area and Wernicke's area in the brain are connected by the arcuate fasciculus, understanding the anatomical location and morphometry of the arcuate fasciculus can help in the treatment of patients with aphasia. We measured the horizontal and vertical curvature ranges of the arcuate fasciculus in both hemispheres in 12 healthy subjects using diffusion tensor tractography. In the right hemisphere, the direct curvature range and indirect curvature range values of the arcuate fasciculus horizontal part were 121.13 ± 5.89 and 25.99 ± 3.01 degrees, respectively, and in the left hemisphere, the values were 121.83 ± 5.33 and 27.40 ± 2.96 degrees, respectively. In the right hemisphere, the direct curvature range and indirect curvature range values of the arcuate fasciculus vertical part were 43.97 ± 7.98 and 30.15 ± 3.82 degrees, respectively, and in the left hemisphere, the values were 39.39 ± 4.42 and 24.08 ± 4.34 degrees, respectively. We believe that the measured curvature ranges are important data for localization and quantitative assessment of specific neuronal pathways in patients presenting with arcuate fasciculus abnormalities.

  14. Medial nucleus tractus solitarius oxytocin receptor signaling and food intake control: the role of gastrointestinal satiation signal processing

    OpenAIRE

    Ong, Zhi Yi; Alhadeff, Amber L; Grill, Harvey J.

    2015-01-01

    Central oxytocin (OT) administration reduces food intake and its effects are mediated, in part, by hindbrain oxytocin receptor (OT-R) signaling. The neural substrate and mechanisms mediating the intake inhibitory effects of hindbrain OT-R signaling are undefined. We examined the hypothesis that hindbrain OT-R-mediated feeding inhibition results from an interaction between medial nucleus tractus solitarius (mNTS) OT-R signaling and the processing of gastrointestinal (GI) satiation signals by n...

  15. Arcuate ligament syndrome inducing hepatic artery thrombosis after liver transplantation

    Institute of Scientific and Technical Information of China (English)

    Zhi-Jun Jiang; Ting-Bo Liang; Xiao-Ning Feng; Wei-Lin Wang; Yan Shen; Min Zhang; Jian Wu; Xiao Xu; Shu-Sen Zheng

    2008-01-01

    BACKGROUND: Hepatic artery thrombosis (HAT) is a frequent complication following liver transplantation, but it is rarely caused by arcuate ligament compression of the celiac artery. This article mainly describes our experience in managing a patient with celiac artery stenosis and HAT after liver transplantation. METHODS: A 44-year-old man with a 15-year history of hepatitis B was admitted to our hospital for hepatocellular carcinoma. Before the operation, he received trans-arterial chemoembolization once, and pretransplant MR angiography indicated a suspected stenosis at the initiation of the celiac artery, while color Doppler showed normal blood lfow in the arterial system. In this case, orthotopic liver transplantation was performed for radical cure of hepatocellular carcinoma. However, B-ultrasonography detected poor blood lfow in the intra- and extra-hepatic artery on the ifrst posttransplant day, and during exploratory laparotomy a thrombus was found in the hepatic artery. Thus, re-transplantation was conducted with a bypass between the graft hepatic artery and the recipient abdominal aorta with the donor's splenic artery. RESULTS: The patient made an uneventful recovery and color Doppler showed good blood lfow in the artery and portal system. Histology conifrmed extensive thrombosis in the left and right hepatic artery of the explanted graft, indicating HAT. CONCLUSIONS: Although HAT caused by celiac trunk compression is rarely reported in liver transplantation, the diagnosis should be considered in patients with pretransplant hepatic artery stenosis on angiography and abnormal blood lfow on B-ultrasonography. Once HAT is formed, treatment such as thrombectomy or re-transplantation should be performed as early as possible.

  16. Depressed GABA and glutamate synaptic signaling by 5-HT1A receptors in the nucleus tractus solitarii and their role in cardiorespiratory function

    OpenAIRE

    Ostrowski, Tim D.; Ostrowski, Daniela; Hasser, Eileen M.; Kline, David D.

    2014-01-01

    Serotonin (5-HT), and its 5-HT1A receptor (5-HT1AR) subtype, is a powerful modulator of the cardiorespiratory system and its sensory reflexes. The nucleus tractus solitarii (nTS) serves as the first central station for visceral afferent integration and is critical for cardiorespiratory reflex responses. However, the physiological and synaptic role of 5-HT1ARs in the nTS is relatively unknown. In the present study, we examined the distribution and modulation of 5-HT1ARs on cardiorespiratory an...

  17. The role of D-serine as co-agonist of NMDA receptors in the nucleus accumbens: relevance to cocaine addiction

    Directory of Open Access Journals (Sweden)

    Marcello eD'Ascenzo

    2014-07-01

    Full Text Available Cocaine addiction is characterized by compulsive drug use despite adverse consequences and high rate of relapse during periods of abstinence. Increasing consensus suggests that addiction to drugs of abuse usurps learning and memory mechanisms normally related to natural rewards, ultimately producing long-lasting neuroadaptations in the mesocorticolimbic system. This system, formed in part by the ventral tegmental area and nucleus accumbens (NAc, has a central role in the development and expression of addictive behaviors. In addition to a broad spectrum of changes that affect morphology and function of NAc excitatory circuits in cocaine–treated animals, impaired N-methyl-D-aspartate receptor (NMDAR-dependent synaptic plasticity is a typical feature. D-serine, a D-amino acid that has been found at high levels in mammalian brain, binds with high affinity the co-agonist site of NMDAR and mediates, along with glutamate, several important processes including synaptic plasticity. Here we review recent literature focusing on cocaine-induced impairment in synaptic plasticity mechanisms in the NAc and on the fundamental role of D-serine as co-agonist of NMDAR in functional and dysfunctional synaptic plasticity within this nucleus. The emerging picture is that reduced D-serine levels play a crucial role in synaptic plasticity relevant to cocaine addiction. This finding opens new perspectives for therapeutic approaches to treat this addictive state.

  18. Reduced Volume of the Arcuate Fasciculus in Adults with High-Functioning Autism Spectrum Conditions.

    Science.gov (United States)

    Moseley, Rachel L; Correia, Marta M; Baron-Cohen, Simon; Shtyrov, Yury; Pulvermüller, Friedemann; Mohr, Bettina

    2016-01-01

    Atypical language is a fundamental feature of autism spectrum conditions (ASC), but few studies have examined the structural integrity of the arcuate fasciculus, the major white matter tract connecting frontal and temporal language regions, which is usually implicated as the main transfer route used in processing linguistic information by the brain. Abnormalities in the arcuate have been reported in young children with ASC, mostly in low-functioning or non-verbal individuals, but little is known regarding the structural properties of the arcuate in adults with ASC or, in particular, in individuals with ASC who have intact language, such as those with high-functioning autism or Asperger syndrome. We used probabilistic tractography of diffusion-weighted imaging to isolate and scrutinize the arcuate in a mixed-gender sample of 18 high-functioning adults with ASC (17 Asperger syndrome) and 14 age- and IQ-matched typically developing controls. Arcuate volume was significantly reduced bilaterally with clearest differences in the right hemisphere. This finding remained significant in an analysis of all male participants alone. Volumetric reduction in the arcuate was significantly correlated with the severity of autistic symptoms as measured by the Autism-Spectrum Quotient. These data reveal that structural differences are present even in high-functioning adults with ASC, who presented with no clinically manifest language deficits and had no reported developmental language delay. Arcuate structural integrity may be useful as an index of ASC severity and thus as a predictor and biomarker for ASC. Implications for future research are discussed. PMID:27242478

  19. The role of γ-aminobutyric acid and its receptors in the nucleus of basal optic root in pigeons

    Institute of Scientific and Technical Information of China (English)

    付煜西; 高宏峰; 王书荣; Stephen A.George

    1997-01-01

    The effects of γ-aminobutyric acid (GABA) and its antagonists bicuculline and 2-hydroxysaclofen on neuronal firings in the nucleus of basal optic root (nBOR) in pigeons were studied by using extracellular recording and microiontophoretic techniques. The results suggest that GABA may be an inhibitory neurotransmitter or modulator within nBOR, functioning by means of main mediation of GABAA receptors and of minor mediation of GABAB receptors. Furthermore, GABA and its GABAA receptors are involved in the modulation of directional selectivity in part of nBOR neurons.

  20. NPY mediates reward activity of morphine, via NPY Y1 receptors, in the nucleus accumbens shell.

    Science.gov (United States)

    Desai, Sagar J; Upadhya, Manoj A; Subhedar, Nishikant K; Kokare, Dadasaheb M

    2013-06-15

    Although the interaction between endogenous neuropeptide Y (NPY) and opioidergic systems in processing of reward has been speculated, experimental evidence is lacking. We investigated the role of NPY, and its Y1 receptors, in the nucleus accumbens shell (AcbSh) in morphine induced reward and reinforcement behavior. Rats were implanted with cannulae targeted at AcbSh for drug administration, and with stimulating electrode in the medial forebrain bundle (MFB). The rats were then conditioned in an operant conditioning chamber for electrical self-stimulation of the MFB. Increased rate of lever pressings was evaluated against the frequency of the stimulating current. Increase in rate of lever presses was considered as a measure of reward and reinforcement. About 30-70% increase in self-stimulation was observed following bilateral intra-AcbSh treatment with morphine, NPY or [Leu(31), Pro(34)]-NPY (NPY Y1/Y5 receptors agonist), however, BIBP3226 (selective NPY Y1 receptors antagonist) produced opposite effect. The reward effect of morphine was significantly potentiated by NPY or [Leu(31), Pro(34)]-NPY, but antagonized by BIBP3226. NPY-immunoreactivity in the AcbSh, arcuate nucleus (ARC) and lateral part of bed nucleus of stria terminalis (BNSTl) was significantly more in the operant conditioned rats than in naïve control. However, morphine administration to the conditioned rats resulted in significant decrease in the NPY-immunoreactivity in all these anatomical regions. Since the role of morphine in modulation of mesolimbic-dopaminergic pathway is well established, we suggest that NPY system in AcbSh, ARC and BNSTl, perhaps acting via Y1-receptor system, may be an important component of the mesolimbic-AcbSh reward circuitry triggered by endogenous opioids.

  1. In silico prediction of escherichia coli proteins targeting the host cell nucleus, with special reference to their role in colon cancer etiology.

    Science.gov (United States)

    Khan, Abdul Arif

    2014-06-01

    The potential role of Escherichia coli in the development of colorectal carcinoma (CRC) has been investigated in many studies. Although the exact mechanism is not clear, chronic inflammation caused by E. coli and other related events are suggested as possible causes behind E. coli-induced colon cancer. It has been found that CRC cells, but not normal cells, are colonized by an intracellular form of E. coli. We predicted nuclear targeting of bacterial proteins in the host cell through computational tools nuclear localization signal (NLS) mapper and balanced subcellular localization predictor (BaCeILo). During intracellular E. coli residence, such targeting is highly likely and may have a possible role in colon cancer etiology. We observed that several gene expression-associated proteins of E. coli can migrate to the host nucleus during intracellular infections. This situation provides an opportunity for competitive interaction of host and pathogen proteins with similar cellular substrates, thereby increasing the chances of development of colon cancer. Moreover, the results indicated that proteins localized in the membrane of E. coli mostly act as secretary proteins in host cells. No exact correlation was observed between NLS prediction and nuclear localization prediction by BaCeILo. This is partly because of a number of reasons, including that only 30% of nuclear proteins carry NLS and that proteins <40 kDa molecular weight can passively target the host nucleus. This study concludes that detection of gene expression-specific E. coli proteins and their targeting of the nucleus may have a profound impact on CRC etiology. PMID:24611522

  2. Further evidence for the role of the caudate nucleus in programming motor and nonmotor behavior in Java monkeys.

    Science.gov (United States)

    Vrijmoed-de Vries, M C; Cools, A R

    1985-01-01

    This study describes the short-term effects of intracaudate microinjections of carbachol in temporarily isolated and restrained Java monkeys. The monkeys were found to display a series of motor disturbances including blepharoptosis, facial twitches, tongue protrusions, ear flattening, torticollis, and compulsive alternations of rapid flexions and extensions of the extremities. In general, carbachol was found to produce consistent effects as far as it concerns its ability to elicit motor disturbances. Three of the five tested monkeys had previously received another series of carbachol injections when they were freely moving and living in a stabilized social group. Accordingly, the present study enabled us to compare the effectiveness of threshold doses of carbachol in the same monkey in two distinct situations. We concluded first, that motor disturbances and disturbances in social communication were closely coupled in relation to the involvement of a particular cholinoceptive substrate within the caudate nucleus of Java monkeys. Second, the motor disturbances under study appeared to require a larger degree of dysfunctioning of this substrate than did subtle disturbances in the social communication of these monkeys. And, finally, stress inherent to restraint increased the susceptibility of the cholinoceptive substrate within the caudate nucleus. The clinical impact of our findings is discussed in view of differences between the premorbid and manifest phases of Parkinson's disease.

  3. Investigating the dynamics of the brain response to music: A central role of the ventral striatum/nucleus accumbens.

    Science.gov (United States)

    Mueller, Karsten; Fritz, Thomas; Mildner, Toralf; Richter, Maxi; Schulze, Katrin; Lepsien, Jöran; Schroeter, Matthias L; Möller, Harald E

    2015-08-01

    Ventral striatal activity has been previously shown to correspond well to reward value mediated by music. Here, we investigate the dynamic brain response to music and manipulated counterparts using functional magnetic resonance imaging (fMRI). Counterparts of musical excerpts were produced by either manipulating the consonance/dissonance of the musical fragments or playing them backwards (or both). Results show a greater involvement of the ventral striatum/nucleus accumbens both when contrasting listening to music that is perceived as pleasant and listening to a manipulated version perceived as unpleasant (backward dissonant), as well as in a parametric analysis for increasing pleasantness. Notably, both analyses yielded a ventral striatal response that was strongest during an early phase of stimulus presentation. A hippocampal response to the musical stimuli was also observed, and was largely mediated by processing differences between listening to forward and backward music. This hippocampal involvement was again strongest during the early response to the music. Auditory cortex activity was more strongly evoked by the original (pleasant) music compared to its manipulated counterparts, but did not display a similar decline of activation over time as subcortical activity. These findings rather suggest that the ventral striatal/nucleus accumbens response during music listening is strongest in the first seconds and then declines.

  4. Arcuate eminence: Is it due to semicircular canal?

    Directory of Open Access Journals (Sweden)

    Manvikar Purushottam Rao

    2012-01-01

    Full Text Available Background: Arcuate eminence (AE is an arc-like elevation seen on the anterior surface of petrous part of temporal bone in the middle cranial fossa (MCF. It has been believed and conventionally taught that AE is a protrusion caused because of the superior semicircular canal (SSC present in the petrous bone. AE is an useful anatomical landmark in the MCF during surgical approaches to acoustic neuroma through suprapetrosal approach. However, the relevance of relation to AE and SSC has been questioned in recent times. Presence of AE of various shapes and dimensions supports this view. Aim: To study and to establish the relation between shape of AE and inferior surface of cerebral hemispheres. Classify various types and subtypes in case of variation in shape based on its appearance. AE could be a negative impression of either gyrus or a sulcus. Material and Methods: The study was conducted in two parts. In the first part, the shape of AE and the impression on cerebral surface were correlated while removing brain from cranial cavity in 8 cadavers (16 wet temporal bones. In second part of the study, 100 dry temporal bones were examined. Relevant photographs were taken. A total of 116 temporal bones were studied. AE was classified as linear, globular, generalized swelling, and flat based on the appearance. Results and Conclusion: 10 AE of 16 wet temporal bones were linear type and did correspond with a sulcus, whilein 1 cadaver no relation was seen. In dry bones, maximum linear variety was seen. There was no relation to shape of AE and cerebral surface in two cadavers. Diversity in shapes, (linear type 47% and correlation with sulci on cerebral surface contests the earlier understanding that AE is due to SSC. Thickness of bone over SSC was not measured in this study. Having seen so many shapes of AE in this study, authors are of the opinion that there is a need to revisit this bony landmark in MCF and rethink if it can be used as a guide in middle

  5. A SAP domain-containing protein shuttles between the nucleus and cell membranes and plays a role in adhesion and migration in D. discoideum

    Directory of Open Access Journals (Sweden)

    Jessica S. Kelsey

    2013-02-01

    The AmpA protein reduces cell adhesion, thereby influencing cell migration in Dictyostelium. To understand how ampA influences cell migration, second site suppressors of an AmpA overexpressing cell line were created by REMI mutagenesis. Mutant candidates were identified by their ability to suppress the large plaques that the AmpA overexpressing cells form on bacterial lawns as a result of their increased rate of migration. One suppressor gene, sma, encodes an uncharacterized protein, which contains a SAP DNA-binding domain and a PTEN-like domain. Using sma gene knockouts and Sma-mRFP expressing cell lines, a role for sma in influencing cell migration was uncovered. Knockouts of the sma gene in a wild-type background enhanced chemotaxis. An additional role for Sma in influencing cell–cell adhesion was also demonstrated. Sma protein transitions between cytosolic and nuclear localizations as a function of cell density. In growing cells migrating to folic acid it is localized to regions of actin polymerization and absent from the nucleus. A role for Sma in influencing ampA mRNA levels is also demonstrated. Sma additionally appears to be involved in ampA pathways regulating cell size, actin polymerization, and cell substrate adhesion. We present insights to the SAP domain-containing group of proteins in Dictyostelium and provide evidence of a role for a SAP domain-containing protein shuttling from the nucleus to sites of actin polymerization during chemotaxis to folic acid and influencing the efficiency of migration.

  6. Pediatric traumatic brain injury: language outcomes and their relationship to the arcuate fasciculus.

    Science.gov (United States)

    Liégeois, Frédérique J; Mahony, Kate; Connelly, Alan; Pigdon, Lauren; Tournier, Jacques-Donald; Morgan, Angela T

    2013-12-01

    Pediatric traumatic brain injury (TBI) may result in long-lasting language impairments alongside dysarthria, a motor-speech disorder. Whether this co-morbidity is due to the functional links between speech and language networks, or to widespread damage affecting both motor and language tracts, remains unknown. Here we investigated language function and diffusion metrics (using diffusion-weighted tractography) within the arcuate fasciculus, the uncinate fasciculus, and the corpus callosum in 32 young people after TBI (approximately half with dysarthria) and age-matched healthy controls (n=17). Only participants with dysarthria showed impairments in language, affecting sentence formulation and semantic association. In the whole TBI group, sentence formulation was best predicted by combined corpus callosum and left arcuate volumes, suggesting this "dual blow" seriously reduces the potential for functional reorganisation. Word comprehension was predicted by fractional anisotropy in the right arcuate. The co-morbidity between dysarthria and language deficits therefore seems to be the consequence of multiple tract damage.

  7. Clinical and radiologic review of uncommon cause of profound iron deficiency anemia: Median arcuate ligament syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Gunduz, Yasemin; Asil, Kiyasrttin; Aksoy, Yakup Ersel; Ayhan, Lacin Tatli [Dept. of Radiology, Sakarya University Medical Faculty, Sakarya (Turkmenistan)

    2014-08-15

    Median arcuate ligament syndrome is an anatomic and clinical entity characterized by dynamic compression of the proximal celiac artery by the median arcuate ligament, which leads to postprandial epigastric pain, vomiting, and weight loss. These symptoms are usually nonspecific and are easily misdiagnosed as functional dyspepsia, peptic ulcer disease, or gastropathy. In this report, we presented a 72-year-old male patient with celiac artery compression syndrome causing recurrent abdominal pain associated with gastric ulcer and iron deficiency anemia. This association is relatively uncommon and therefore not well determined. In addition, we reported the CT angiography findings and three-dimensional reconstructions of this rare case.

  8. Emerging role for corticotropin releasing factor signaling in the bed nucleus of the stria terminalis at the intersection of stress and reward.

    Science.gov (United States)

    Silberman, Yuval; Winder, Danny G

    2013-01-01

    Stress and anxiety play an important role in the development and maintenance of drug and alcohol addiction. The bed nucleus of the stria terminalis (BNST), a brain region involved in the production of long-term stress-related behaviors, plays an important role in animal models of relapse, such as reinstatement to previously extinguished drug-seeking behaviors. While a number of neurotransmitter systems have been suggested to play a role in these behaviors, recent evidence points to the neuropeptide corticotropin releasing factor (CRF) as being critically important in BNST-mediated reinstatement behaviors. Although numerous studies indicate that the BNST is a complex brain region with multiple afferent and efferent systems and a variety of cell types, there has only been limited work to determine how CRF modulates this complex neuronal system at the circuit level. Recent work from our lab and others have begun to unravel these BNST neurocircuits and explore their roles in CRF-related reinstatement behaviors. This review will examine the role of CRF signaling in drug addiction and reinstatement with an emphasis on critical neurocircuitry within the BNST that may offer new insights into treatments for addiction.

  9. Effect of perinatal asphyxia on tuberomammillary nucleus neuronal density and object recognition memory: A possible role for histamine?

    Science.gov (United States)

    Flores-Balter, Gabriela; Cordova-Jadue, Héctor; Chiti-Morales, Alessandra; Lespay, Carolyne; Espina-Marchant, Pablo; Falcon, Romina; Grinspun, Noemi; Sanchez, Jessica; Bustamante, Diego; Morales, Paola; Herrera-Marschitz, Mario; Valdés, José L

    2016-10-15

    Perinatal asphyxia (PA) is associated with long-term neuronal damage and cognitive deficits in adulthood, such as learning and memory disabilities. After PA, specific brain regions are compromised, including neocortex, hippocampus, basal ganglia, and ascending neuromodulatory pathways, such as dopamine system, explaining some of the cognitive disabilities. We hypothesize that other neuromodulatory systems, such as histamine system from the tuberomammillary nucleus (TMN), which widely project to telencephalon, shown to be relevant for learning and memory, may be compromised by PA. We investigated here the effect of PA on (i) Density and neuronal activity of TMN neurons by double immunoreactivity for adenosine deaminase (ADA) and c-Fos, as marker for histaminergic neurons and neuronal activity respectively. (ii) Expression of the histamine-synthesizing enzyme, histidine decarboxylase (HDC) by western blot and (iii) thioperamide an H3 histamine receptor antagonist, on an object recognition memory task. Asphyxia-exposed rats showed a decrease of ADA density and c-Fos activity in TMN, and decrease of HDC expression in hypothalamus. Asphyxia-exposed rats also showed a low performance in object recognition memory compared to caesarean-delivered controls, which was reverted in a dose-dependent manner by the H3 antagonist thioperamide (5-10mg/kg, i.p.). The present results show that the histaminergic neuronal system of the TMN is involved in the long-term effects induced by PA, affecting learning and memory. PMID:27444242

  10. Bi-directional CB1 receptor-mediated cardiovascular effects of cannabinoids in anaesthetized rats: role of the paraventricular nucleus.

    Science.gov (United States)

    Grzeda, E; Schlicker, E; Luczaj, W; Harasim, E; Baranowska-Kuczko, M; Malinowska, B

    2015-06-01

    The activation of cannabinoid CB1 receptors decreases and increases blood pressure (BP) in anaesthetized and conscious rats, respectively. The aim of our study was to check the possible involvement of CB1 receptors in the paraventricular nucleus of the hypothalamus (PVN) in the cardiovascular effects of cannabinoids in rats. Methanandamide (metabolically stable analogue of the endocannabinoid anandamide) and the synthetic cannabinoid receptor agonist CP55940 were microinjected into the PVN of urethane-anaesthetized rats twice (S1 and S2, 20 min apart). Receptor antagonists were administered intravenously (i.v.) 5 min before S1. Methanandamide and CP55940 decreased blood pressure by 15 - 20%. The CB1 receptor antagonist AM251 reversed the depressor effect into a pressor response of 20 - 30%. The pressor effect of CP55940 observed in the presence of AM251 i.v. was reduced by AM251 given additionally into the PVN but not by the i.v. injection of the CB2 antagonist SR144528 or the vanilloid TRPV1 antagonist ruthenium red. In the presence of the peripherally restricted CB1 receptor antagonist AM6545, CP55940 given into the PVN increased BP by 40%. AM6545 reversed the decrease in BP induced by CP55940 i.v. into a marked increase. Bilateral chemical lesion of the PVN by kainic acid abolished all cardiovascular effects of CP55940 i.v. In conclusion, the cannabinoid CP55940 administered to the PVN of urethane-anaesthetized rats can induce depressor and pressor effects. The direction of the response probably depends on the sympathetic tone. The centrally induced hypertensive response of CP55940 can, in addition, be masked by peripheral CB1 receptors.

  11. Role of α{sub 2}-adrenoceptors in the lateral parabrachial nucleus in the control of body fluid homeostasis

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, C.A.F.; Andrade-Franzé, G.M.F.; De Paula, P.M.; De Luca, L.A. Jr.; Menani, J.V. [Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP (Brazil)

    2014-01-10

    Central α{sub 2}-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α{sub 2}-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α{sub 2}-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α{sub 2}-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α{sub 2}-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α{sub 2}-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion.

  12. Medial nucleus tractus solitarius oxytocin receptor signaling and food intake control: the role of gastrointestinal satiation signal processing.

    Science.gov (United States)

    Ong, Zhi Yi; Alhadeff, Amber L; Grill, Harvey J

    2015-05-01

    Central oxytocin (OT) administration reduces food intake and its effects are mediated, in part, by hindbrain oxytocin receptor (OT-R) signaling. The neural substrate and mechanisms mediating the intake inhibitory effects of hindbrain OT-R signaling are undefined. We examined the hypothesis that hindbrain OT-R-mediated feeding inhibition results from an interaction between medial nucleus tractus solitarius (mNTS) OT-R signaling and the processing of gastrointestinal (GI) satiation signals by neurons of the mNTS. Here, we demonstrated that mNTS or fourth ventricle (4V) microinjections of OT in rats reduced chow intake in a dose-dependent manner. To examine whether the intake suppressive effects of mNTS OT-R signaling is mediated by GI signal processing, rats were injected with OT to the 4V (1 μg) or mNTS (0.3 μg), followed by self-ingestion of a nutrient preload, where either treatment was designed to be without effect on chow intake. Results showed that the combination of mNTS OT-R signaling and GI signaling processing by preload ingestion reduced chow intake significantly and to a greater extent than either stimulus alone. Using enzyme immunoassay, endogenous OT content in mNTS-enriched dorsal vagal complex (DVC) in response to ingestion of nutrient preload was measured. Results revealed that preload ingestion significantly elevated endogenous DVC OT content. Taken together, these findings provide evidence that mNTS neurons are a site of action for hindbrain OT-R signaling in food intake control and that the intake inhibitory effects of hindbrain mNTS OT-R signaling are mediated by interactions with GI satiation signal processing by mNTS neurons.

  13. Role of α2-adrenoceptors in the lateral parabrachial nucleus in the control of body fluid homeostasis

    International Nuclear Information System (INIS)

    Central α2-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α2-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α2-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α2-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α2-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion

  14. A NEW GENERATING METHOD FOR THE MACHINING OF A CYLINDRICAL GEAR WITH SYMMETRIC ARCUATE TOOTH TRACE

    Institute of Scientific and Technical Information of China (English)

    马振群; 龚堰珏; 王小椿

    2004-01-01

    Objective To introduce a new generating method for the machining of a cylindrical gear with symmetric arcuate tooth trace. Methods Adopting this method, the key problems of mismatch control and manufacturing of symmetric arcuate tooth trace gears are solved by using suitable cutter tilt and a new generating method with double-edge gear-wheel cutter. The machining principle is analyzed and the mathematical model of generating motion is established. Then the tooth flank equation and differential geometrical parameters are discussed. Results The minim alteration of cutter tilt will make the contact flank area change so as to satisfy the special requirements. It is easy to realize the tip relief of gearing by altering coefficients of every moving axis. Because the tooth has the arc shape, the symmetrical arcuate cylindrical gears have higher overall strength and it is easy to perform the flank grinding for high precision. Conclusion This new generating method has higher productivity. It is easy to get a perfect contact zone and fully give play to the potential bearing capacity of the gears. The symmetrical arcuate cylindrical gears can be used in highly durable and heavy duty gearing applications.

  15. Decoding the superior parietal lobule connections of the superior longitudinal fasciculus/arcuate fasciculus in the human brain.

    Science.gov (United States)

    Kamali, A; Sair, H I; Radmanesh, A; Hasan, K M

    2014-09-26

    The temporo-parietal (TP) white matter connections between the inferior parietal lobule and superior temporal gyrus as part of the superior longitudinal fasciculus/arcuate fasciculus (SLF/AF) or middle longitudinal fasciculus (MdLF) have been studied in prior diffusion tensor tractography (DTT) studies. However, few studies have been focusing on the higher TP connections of the superior parietal lobule with the temporal lobe. These higher TP connections have been shown to have a role in core processes such as attention, memory, emotions, and language. Our most recent study, for the first time, hinted to the possibility of a long white matter connection interconnecting the superior parietal lobule (SPL) with the posterior temporal lobe in human brain which we call the SLF/AF TP-SPL and for a shorter abbreviation, the TP-SPL. We decided to further investigate this white matter connection using fiber assignment by continuous tracking deterministic tractography and high spatial resolution diffusion tensor imaging on 3T. Five healthy right-handed men (age range 24-37 years) were studied. We delineated the SPL connections of the SLF/AF TP bilaterally in five normal adult human brains. Using a high resolution DTT technique, we demonstrate for the first time, the trajectory of a long fiber bundle connectivity between the SPL and posterior temporal lobe, called the SLF/AF TP-SPL (or the TP-SPL), bilaterally in five healthy adult human brains. We also demonstrate the trajectory of the vertically oriented posterior TP connections, interconnecting the inferior parietal lobule (IPL) with the posterior temporal lobe (TP-IPL) in relation to the TP-SPL, arcuate fasciculus and other major language pathways. In the current study, for the first time, we categorized the TP connections into the anterior and posterior connectivity groups and subcategorized each one into the SPL or IPL connections. PMID:25086308

  16. Apolipoprotein A-IV inhibits AgRP/NPY neurons and activates POMC neurons in the arcuate nucleus

    Science.gov (United States)

    Apolipoprotein A-IV (apoA-IV) in the brain potently suppresses food intake. However the mechanisms underlying its anorexigenic effects remain to be identified. We first examined the effects of apoA-IV on cellular activities in hypothalamic neurons that co-express agouti-related peptide (AgRP) and ne...

  17. Direct regulation of GnRH neuron excitability by arcuate nucleus POMC and NPY neuron neuropeptides in female mice.

    Science.gov (United States)

    Roa, Juan; Herbison, Allan E

    2012-11-01

    Hypothalamic neuropeptide Y (NPY) and proopiomelanocortin (POMC) neurons act to sense and coordinate the brain's responses to metabolic cues. One neuronal network that is very sensitive to metabolic status is that controlling fertility. In this study, we investigated the impact of neuropeptides released by NPY and POMC neurons on the cellular excitability of GnRH neurons, the final output cells of the brain controlling fertility. The majority (∼70%) of GnRH neurons were activated by α-melanocyte-stimulating hormone, and this resulted from the direct postsynaptic activation of melanocortin receptor 3 and melanocortin receptor 4. A small population of GnRH neurons (∼15%) was excited by cocaine and amphetamine-regulated transcript or inhibited by β-endorphin. Agouti-related peptide, released by NPY neurons, was found to have variable inhibitory (∼10%) and stimulatory (∼25%) effects upon subpopulations of GnRH neurons. A variety of NPY and pancreatic polypeptide analogs was used to examine potential NPY interactions with GnRH neurons. Although porcine NPY (Y1/Y2/Y5 agonist) directly inhibited the firing of approximately 45% of GnRH neurons, [Leu(31),Pro(34)]-NPY (Y1/Y4/Y5 agonist) could excite (56%) or inhibit (19%). Experiments with further agonists indicated that Y1 receptors were responsible for suppressing GnRH neuron activity, whereas postsynaptic Y4 receptors were stimulatory. These results show that the activity of GnRH neurons is regulated in a complex manner by neuropeptides released by POMC and NPY neurons. This provides a direct route through which different metabolic cues can regulate fertility.

  18. Acute inflammation reduces kisspeptin immunoreactivity at the arcuate nucleus and decreases responsiveness to kisspeptin independently of its anorectic effects

    DEFF Research Database (Denmark)

    Castellano, J M; Bentsen, A H; Romero, M;

    2010-01-01

    Severe inflammatory challenges are frequently coupled to decreased food intake and disruption of reproductive function, the latter via deregulation of different signaling pathways that impinge onto GnRH neurons. Recently, the hypothalamic Kiss1 system, a major gatekeeper of GnRH function, was sug...

  19. Neutrino-nucleus interactions

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, H.; /Tufts U.; Garvey, G.; /Los Alamos; Zeller, G.P.; /Fermilab

    2011-01-01

    The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.

  20. PGC-1 family coactivators and cell fate: roles in cancer, neurodegeneration, cardiovascular disease and retrograde mitochondria-nucleus signalling.

    OpenAIRE

    Jones, A W; Z. Yao; Vicencio, J. M.; Karkucinska-Wieckowska, A.; Szabadkai, G.

    2012-01-01

    Over the past two decades, a complex nuclear transcriptional machinery controlling mitochondrial biogenesis and function has been described. Central to this network are the PGC-1 family coactivators, characterised as master regulators of mitochondrial biogenesis. Recent literature has identified a broader role for PGC-1 coactivators in both cell death and cellular adaptation under conditions of stress, here reviewed in the context of the pathology associated with cancer, neurodegeneration and...

  1. The role of nucleus accumbens core/shell in sleep-wake regulation and their involvement in modafinil-induced arousal.

    Directory of Open Access Journals (Sweden)

    Mei-Hong Qiu

    Full Text Available BACKGROUND: We have previously shown that modafinil promotes wakefulness via dopamine receptor D(1 and D(2 receptors; however, the locus where dopamine acts has not been identified. We proposed that the nucleus accumbens (NAc that receives the ventral tegmental area dopamine inputs play an important role not only in reward and addiction but also in sleep-wake cycle and in mediating modafinil-induced arousal. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we further explored the role of NAc in sleep-wake cycle and sleep homeostasis by ablating the NAc core and shell, respectively, and examined arousal response following modafinil administration. We found that discrete NAc core and shell lesions produced 26.5% and 17.4% increase in total wakefulness per day, respectively, with sleep fragmentation and a reduced sleep rebound after a 6-hr sleep deprivation compared to control. Finally, NAc core but not shell lesions eliminated arousal effects of modafinil. CONCLUSIONS/SIGNIFICANCE: These results indicate that the NAc regulates sleep-wake behavior and mediates arousal effects of the midbrain dopamine system and stimulant modafinil.

  2. The roles of the nucleus accumbens core, dorsomedial striatum, and dorsolateral striatum in learning: performance and extinction of Pavlovian fear-conditioned responses and instrumental avoidance responses.

    Science.gov (United States)

    Wendler, Etieli; Gaspar, Jessica C C; Ferreira, Tatiana L; Barbiero, Janaína K; Andreatini, Roberto; Vital, Maria A B F; Blaha, Charles D; Winn, Philip; Da Cunha, Claudio

    2014-03-01

    This study examined the effects of bilateral excitotoxic lesions of the nucleus accumbens core (NAc-co), dorsomedial striatum (DMS) or dorsolateral striatum (DLS) of rats on the learning and extinction of Pavlovian and instrumental components of conditioned avoidance responses (CARs). None of the lesions caused sensorimotor deficits that could affect locomotion. Lesions of the NAc-co, but not DMS or DLS, decreased unconditioned and conditioned freezing. The NAc-co and DLS lesioned rats learned the 2-way active avoidance task more slowly. These results suggest: (i) CARs depend on both Pavlovian and instrumental learning; (ii) learning the Pavlovian component of CARs depends on the NAc-co; learning the instrumental component of CARs depends on the DLS, NAc and DMS; (iii) although the NAc-co is also needed for learning the instrumental component, it is not clear whether it plays a role in learning the instrumental component per se or if it simply allows learning of the Pavlovian component which is a pre-condition for learning the instrumental component; (iv) we did not find evidence that the DMS and DLS play the same roles in habit and goal-directed aspects of the instrumental component of CARs as observed in appetitive motivated instrumental responding.

  3. THE ROLE OF NUCLEUS RAPHE MAGNUS IN THE ANTINOCICEPTIVE EFFECT OF MUSCLE SPINDLE AFFERENTS IN THE RAT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To investigate the role of NRM in the antinociceptive effect of muscle spindle afferents, the influence of NRM lesion on the inhibitory effect of muscle spindle afferents on the nociceptive responses of wide dynamic range (WDR) neurons and the effects of the muscle spindle afferents on the NRM neuronal activities were observed. Methods The single units of WDR neurons in the spinal dorsal horn were recorded extracellularly, and the inhibitory effects of activating muscle spindle afferents by intravenous administration of succinyicholine (SCH) on the C-fibers evoked responses (C-responses) of WDR neurons were tested before and after lesion of NRM. The ef- fects of the muscle spindle afferents activated by administrating SCH on the single NRM neurons were also examined. Results ①lt was found that the C-responses of WDR neurons were significantly inhibited by intravenously adminis- tration of SCH, and the inhibitory effect was reduced after lesion of NRM ;②The activities of most of the NRM neu- rons could be changed significantly by administrating SCH. According to their responses, NRM neurons could be classified into three types:excitatory, inhibitory and non-responsive neurons, and the responses were dose-depen- dent. Conclusion These results suggest that the muscle spindle afferents evoked by SCH may activate the NRM neu- rons, which plays an important role in the antinociception of muscle spindle afferents.

  4. Nuclear aspects of neutral current non-standard ν-nucleus reactions and the role of the exotic μ-→e- transitions experimental limits

    Science.gov (United States)

    Papoulias, D. K.; Kosmas, T. S.

    2014-01-01

    The nuclear aspects of flavour changing neutral current (FCNC) processes, predicted by various new-physics models to occur in the presence of nuclei, are examined by computing the relevant nuclear matrix elements within the context of the quasi-particle RPA using realistic strong two-body forces. One of our aims is to explore the role of the non-standard interactions (NSI) in the leptonic sector and specifically: (i) in lepton flavour violating (LFV) processes involving the neutral particles νℓ and ν, ℓ=e,μ,τ and (ii) in charged lepton flavour violating (cLFV) processes involving the charged leptons ℓ- or ℓ+. As concrete nuclear systems we have chosen the stopping targets of μ-→e- conversion experiments, i.e. the 48Ti nucleus of the PRIME/PRISM experiment at J-PARC and the 27Al of the COMET at J-PARC as well as of the Mu2e at Fermilab. These experiments have been designed to reduce the single event sensitivity down to 10-16-10-18 in searching for charged lepton mixing events. Our goal is, by taking advantage of our detailed nuclear structure calculations and using the present limits or the sensitivity of the aforementioned exotic μ-→e- experiments, to put stringent constraints on the parameters of NSI Lagrangians.

  5. PYY(3-36) Induces Fos in the Arcuate Nucleus and in both Catecholaminergic and Non-catecholaminergic Neurons in the Nucleus Tractus Solitarius of Rats

    OpenAIRE

    Blevins, J. E.; Chelikani, P. K.; Haver, A. C.; Reidelberger, R. D.

    2007-01-01

    Peptide YY (3-36) [PYY(3-36)] inhibits feeding in rodents, nonhuman primates and humans, yet the neural circuits underlying this action remain to be determined. Here we assessed whether PYY(3-36) inhibits feeding by activating neurons in forebrain and hindbrain sites containing Y2 receptors and linked to control of food intake, or in hindbrain sites immediately downstream of vagal afferent neurons. Rats received an anorexigenic dose of PYY(3-36), and the number of neurons expressing Fos, an i...

  6. Role of orexin-2 receptors in the nucleus accumbens in antinociception induced by carbachol stimulation of the lateral hypothalamus in formalin test.

    Science.gov (United States)

    Yazdi, Fatemeh; Jahangirvand, Mahboubeh; Ezzatpanah, Somayeh; Haghparast, Abbas

    2016-08-01

    Orexins, which are mainly produced by orexin-expressing neurons in the lateral hypothalamus (LH), play an important role in pain modulation. Previously, it has been established that the nucleus accumbens (NAc) is involved in the modulation of formalin-induced nociceptive responses, a model of tonic pain. In this study, the role of intra-accumbal orexin-2 receptors (OX2rs) in the mediation of formalin-induced pain was investigated. A volume of 0.5 μl of 10, 20, and 40 nmol/l solutions of TCS OX2 29, an OX2r antagonist, were unilaterally microinjected into the NAc 5 min before an intra-LH carbachol microinjection (0.5 μl of 250 nmol/l solution). After 5 min, animals received a subcutaneous injection of formalin 2.5% (50 μl) into the hind paw. Pain-related behaviors were assessed at 5 min intervals during a 60-min test period. The findings showed that TCS OX2 29 administration dose dependently blocked carbachol-induced antinociception during both phases of formalin-induced pain. The antianalgesic effect of TCS OX2 29 was greater during the late phase compared with the early phase. These observations suggest that the NAc, as a part of a descending pain-modulatory circuitry, partially mediates LH-induced analgesia in the formalin test through recruitment of OX2rs. This makes the orexinergic system a good potential therapeutic target in the control of persistent inflammatory pain. PMID:26871404

  7. Opposing roles of corticotropin-releasing factor and neuropeptide Y within the dorsolateral bed nucleus of the stria terminalis in the negative affective component of pain in rats.

    Science.gov (United States)

    Ide, Soichiro; Hara, Taiki; Ohno, Atsushi; Tamano, Ryuta; Koseki, Kana; Naka, Tomonori; Maruyama, Chikashi; Kaneda, Katsuyuki; Yoshioka, Mitsuhiro; Minami, Masabumi

    2013-04-01

    Pain is a complex experience composed of sensory and affective components. Although the neural systems of the sensory component of pain have been studied extensively, those of its affective component remain to be determined. In the present study, we examined the effects of corticotropin-releasing factor (CRF) and neuropeptide Y (NPY) injected into the dorsolateral bed nucleus of the stria terminalis (dlBNST) on pain-induced aversion and nociceptive behaviors in rats to examine the roles of these peptides in affective and sensory components of pain, respectively. In vivo microdialysis showed that formalin-evoked pain enhanced the release of CRF in this brain region. Using a conditioned place aversion (CPA) test, we found that intra-dlBNST injection of a CRF1 or CRF2 receptor antagonist suppressed pain-induced aversion. Intra-dlBNST CRF injection induced CPA even in the absence of pain stimulation. On the other hand, intra-dlBNST NPY injection suppressed pain-induced aversion. Coadministration of NPY inhibited CRF-induced CPA. This inhibitory effect of NPY was blocked by coadministration of a Y1 or Y5 receptor antagonist. Furthermore, whole-cell patch-clamp electrophysiology in dlBNST slices revealed that CRF increased neuronal excitability specifically in type II dlBNST neurons, whereas NPY decreased it in these neurons. Excitatory effects of CRF on type II dlBNST neurons were suppressed by NPY. These results have uncovered some of the neuronal mechanisms underlying the affective component of pain by showing opposing roles of intra-dlBNST CRF and NPY in pain-induced aversion and opposing actions of these peptides on neuronal excitability converging on the same target, type II neurons, within the dlBNST.

  8. A critical role of nucleus accumbens dopamine D1-family receptors in renewal of alcohol seeking after punishment-imposed abstinence.

    Science.gov (United States)

    Marchant, Nathan J; Kaganovsky, Konstantin

    2015-06-01

    In humans, places or contexts previously associated with alcohol use often provoke relapse during abstinence. This phenomenon is modeled in laboratory animals using the ABA renewal procedure, in which extinction training in context (B) suppresses alcohol seeking, and renewal of this seeking occurs when the animal returns to the original training context (A). However, extinction training does not adequately capture the motivation for abstinence in human alcoholics who typically self-initiate abstinence in response to the negative consequences of excessive use. We recently developed a procedure to study renewal in laboratory rats after abstinence imposed by negative consequences (footshock punishment). The mechanisms of renewal of punished alcohol seeking are largely unknown. Here, we used the D1-family receptor antagonist SCH 23390 to examine the role of nucleus accumbens (NAc) shell and core dopamine in renewal of alcohol seeking after punishment-imposed abstinence. We trained alcohol-preferring "P rats" to self-administer 20% alcohol in Context A and subsequently suppressed alcohol taking via response-contingent footshock punishment in Context B. We tested the effects of systemic, NAc shell, or NAc core injections of SCH 23390 on renewal of alcohol seeking after punishment-imposed abstinence. We found that both systemic and NAc shell and core injections of SCH 23390 decreased renewal of punished alcohol seeking. Our results demonstrate a critical role of NAc dopamine in renewal of alcohol seeking after punishment-imposed abstinence. We discuss these results in reference to the brain mechanisms of renewal of alcohol seeking after extinction versus punishment.

  9. A critical role of nucleus accumbens dopamine D1-family receptors in renewal of alcohol seeking after punishment-imposed abstinence.

    Science.gov (United States)

    Marchant, Nathan J; Kaganovsky, Konstantin

    2015-06-01

    In humans, places or contexts previously associated with alcohol use often provoke relapse during abstinence. This phenomenon is modeled in laboratory animals using the ABA renewal procedure, in which extinction training in context (B) suppresses alcohol seeking, and renewal of this seeking occurs when the animal returns to the original training context (A). However, extinction training does not adequately capture the motivation for abstinence in human alcoholics who typically self-initiate abstinence in response to the negative consequences of excessive use. We recently developed a procedure to study renewal in laboratory rats after abstinence imposed by negative consequences (footshock punishment). The mechanisms of renewal of punished alcohol seeking are largely unknown. Here, we used the D1-family receptor antagonist SCH 23390 to examine the role of nucleus accumbens (NAc) shell and core dopamine in renewal of alcohol seeking after punishment-imposed abstinence. We trained alcohol-preferring "P rats" to self-administer 20% alcohol in Context A and subsequently suppressed alcohol taking via response-contingent footshock punishment in Context B. We tested the effects of systemic, NAc shell, or NAc core injections of SCH 23390 on renewal of alcohol seeking after punishment-imposed abstinence. We found that both systemic and NAc shell and core injections of SCH 23390 decreased renewal of punished alcohol seeking. Our results demonstrate a critical role of NAc dopamine in renewal of alcohol seeking after punishment-imposed abstinence. We discuss these results in reference to the brain mechanisms of renewal of alcohol seeking after extinction versus punishment. PMID:25914922

  10. Estrogen and Growth Hormone and their Roles in Reproductive Function

    Directory of Open Access Journals (Sweden)

    Hüseyin Baki ÇİFTCİ

    2013-02-01

    Full Text Available The aim of this study was to review the effect of estrogen on growth hormone secretion and the roles of estrogen and growth hormone in reproductive function. Estrogen is the main hormone affecting growth, development, maturation and functioning of reproductive tract as well as the sexual differentiation and the behavior. Growth hormone is also important factor in sexual maturation and attainment of puberty. The impact of estrogen on growth hormone secretion has been reported in rodents and primates. However, the precise mechanism for the alterations in growth hormone secretion is not clearly known. Estrogen may possibility have a direct affect on growth hormone secretion via the binding to estrogen receptor-α due to its co-expression in growth hormone neurons in the medial preoptic area and arcuate nucleus. Estrogen may also have an indirect effect via the reducing insulin-like growth factor-1 feedback inhibition resulting with increased growth hormone secretion.

  11. Role of the origin of glutamatergic synaptic inputs in controlling synaptic plasticity and its modulation by alcohol in mice nucleus accumbens

    OpenAIRE

    Gilles Erwann Martin; Xincai eJi; Sucharita eSaha

    2015-01-01

    It is widely accepted that long-lasting changes of synaptic strength in the nucleus accumbens, a brain region involved in drug reward, mediate acute and chronic effects of alcohol. However, our understanding of the mechanisms underlying the effects of alcohol on synaptic plasticity is limited by the fact that the nucleus accumbens receives glutamatergic inputs from distinct brain regions (e.g. the prefrontal cortex, the amygdala and the hippocampus), each region providing different informatio...

  12. The Possible Role of TASK Channels in Rank-Ordered Recruitment of Motoneurons in the Dorsolateral Part of the Trigeminal Motor Nucleus.

    Science.gov (United States)

    Okamoto, Keiko; Emura, Norihito; Sato, Hajime; Fukatsu, Yuki; Saito, Mitsuru; Tanaka, Chie; Morita, Yukako; Nishimura, Kayo; Kuramoto, Eriko; Xu Yin, Dong; Furutani, Kazuharu; Okazawa, Makoto; Kurachi, Yoshihisa; Kaneko, Takeshi; Maeda, Yoshinobu; Yamashiro, Takashi; Takada, Kenji; Toyoda, Hiroki; Kang, Youngnam

    2016-01-01

    Because a rank-ordered recruitment of motor units occurs during isometric contraction of jaw-closing muscles, jaw-closing motoneurons (MNs) may be recruited in a manner dependent on their soma sizes or input resistances (IRs). In the dorsolateral part of the trigeminal motor nucleus (dl-TMN) in rats, MNs abundantly express TWIK (two-pore domain weak inwardly rectifying K channel)-related acid-sensitive-K(+) channel (TASK)-1 and TASK3 channels, which determine the IR and resting membrane potential. Here we examined how TASK channels are involved in IR-dependent activation/recruitment of MNs in the rat dl-TMN by using multiple methods. The real-time PCR study revealed that single large MNs (>35 μm) expressed TASK1 and TASK3 mRNAs more abundantly compared with single small MNs (15-20 μm). The immunohistochemistry revealed that TASK1 and TASK3 channels were complementarily distributed in somata and dendrites of MNs, respectively. The density of TASK1 channels seemed to increase with a decrease in soma diameter while there were inverse relationships between the soma size of MNs and IR, resting membrane potential, or spike threshold. Dual whole-cell recordings obtained from smaller and larger MNs revealed that the recruitment of MNs depends on their IRs in response to repetitive stimulation of the presumed Ia afferents. 8-Bromoguanosine-cGMP decreased IRs in small MNs, while it hardly changed those in large MNs, and subsequently decreased the difference in spike-onset latency between the smaller and larger MNs, causing a synchronous activation of MNs. These results suggest that TASK channels play critical roles in rank-ordered recruitment of MNs in the dl-TMN. PMID:27482536

  13. N-methyl-D-aspartate receptor-mediated glutamate transmission in nucleus accumbens plays a more important role than that in dorsal striatum in cognitive flexibility

    Directory of Open Access Journals (Sweden)

    Xuekun eDing

    2014-09-01

    Full Text Available Cognitive flexibility is a critical ability for adapting to an ever-changing environment in humans and animals. Deficits in cognitive flexibility are observed in most schizophrenia patients. Previous studies reported that the medial prefrontal cortex-to-ventral striatum and orbital frontal cortex-to-dorsal striatum circuits play important roles in extra- and intra-dimensional strategy switching, respectively. However, the precise function of striatal subregions in flexible behaviors is still unclear. N-methyl-D-aspartate receptors (NMDARs are major glutamate receptors in the striatum that receive glutamatergic projections from the frontal cortex. The membrane insertion of Ca2+-permeable α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors (AMPARs depends on NMDAR activation and is required in learning and memory processes. In the present study, we measured set-shifting and reversal learning performance in operant chambers in rats and assessed the effects of blocking NMDARs and Ca2+-permeable AMPARs in striatal subregions on behavioral flexibility. The blockade of NMDARs in the nucleus accumbens (NAc core by AP5 impaired set-shifting ability by causing a failure to modify prior learning. The suppression of NMDAR-mediated transmission in the NAc shell induced a deficit in set-shifting by disrupting the learning and maintenance of novel strategies. During reversal learning, infusions of AP5 into the NAc shell and core impaired the ability to learn and maintain new strategies. However, behavioral flexibility was not significantly affected by blocking NMDARs in the dorsal striatum. We also found that the blockade of Ca2+-permeable AMPARs by NASPM in any subregion of the striatum did not affect strategy switching. These findings suggest that NMDAR-mediated glutamate transmission in the NAc contributes more to cognitive execution compared with the dorsal striatum.

  14. Anti-nociceptive role of neuropeptide Y in the nucleus accumbens in rats with inflammation, an effect modulated by mu- and kappa-opioid receptors

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Recent study in our laboratory showed that neuropeptide Y (NPY) plays an antinociceptive role in the nucleus accumbens (NAc) in intact rats. The present study was performed to further investigate the effect of NPY in nociceptive modulation in the NAc of rats with inflammation, and the possible interaction between NPY and the opioid systems. Experimental inflammation was induced by subcutaneous injection of carrageenan into the left hindpaw of rats. Intra-NAc administration of NPY induced a dose-dependent increase of hindpaw withdrawal latencies (HWLs) to thermal and mechanical stimulations in rats with inflammation. The anti-nociceptive effect of NPY was significantly blocked by subsequent intra-NAc injection of the Y1 receptor antagonist NPY28-36, suggesting an involvement of Y1 receptor in the NPY-induced anti-nociception. Furthermore, intra-NAc administration of the opioid antagonist naloxone significantly antagonized the increased HWLs induced by preceding intra-NAc injection of NPY, suggesting an involvement of the endogenous opioid system in the NPY-induced anti-nociception in the NAc during inflammation. Moreover, the NPY-induced anti-nociception was attenuated by following intra-NAc injection of the μ-opioid antagonist β-funaltrexamine (β-FNA), and κ-opioid antagonist nor-binaltorphimine (norBNI), but not by δ-opioid antagonist naltrindole, indicating that μ- and κ-opioid receptors, not δ-opioid receptor, are involved in the NPY-induced anti-nociception in the NAc in rats with inflammation.

  15. Role of reuniens nucleus projections to the medial prefrontal cortex and to the hippocampal pyramidal CA1 area in associative learning.

    Directory of Open Access Journals (Sweden)

    Lyndell Eleore

    Full Text Available We studied the interactions between short- and long-term plastic changes taking place during the acquisition of a classical eyeblink conditioning and following high-frequency stimulation (HFS of the reuniens nucleus in behaving mice. Synaptic changes in strength were studied at the reuniens-medial prefrontal cortex (mPFC and the reuniens-CA1 synapses. Input/output curves and a paired-pulse study enabled determining the functional capabilities of the two synapses and the optimal intensities to be applied at the reuniens nucleus during classical eyeblink conditioning and for HFS applied to the reuniens nucleus. Animals were conditioned using a trace paradigm, with a tone as conditioned stimulus (CS and an electric shock to the trigeminal nerve as unconditioned stimulus (US. A single pulse was presented to the reuniens nucleus to evoke field EPSPs (fEPSPs in mPFC and CA1 areas during the CS-US interval. No significant changes in synaptic strength were observed at the reuniens-mPFC and reuniens-CA1 synapses during the acquisition of eyelid conditioned responses (CRs. Two successive HFS sessions carried out during the first two conditioning days decreased the percentage of CRs, without evoking any long-term potentiation (LTP at the recording sites. HFS of the reuniens nucleus also prevented the proper acquisition of an object discrimination task. A subsequent study revealed that HFS of the reuniens nucleus evoked a significant decrease of paired-pulse facilitation. In conclusion, reuniens nucleus projections to prefrontal and hippocampal circuits seem to participate in the acquisition of associative learning through a mechanism that does not required the development of LTP.

  16. Roles for pituitary adenylate cyclase-activating peptide (PACAP) expression and signaling in the bed nucleus of the stria terminalis (BNST) in mediating the behavioral consequences of chronic stress

    OpenAIRE

    Hammack, Sayamwong E.; Roman, Carolyn W.; Lezak, Kimberly R.; Kocho-Shellenberg, Margaret; Grimmig, Bethany; Falls, William A; Braas, Karen; May, Victor

    2010-01-01

    Anxiety disorders are frequently long-lasting and debilitating for more than 40 million American adults. Although stressor exposure plays an important role in the etiology of some anxiety disorders, the mechanisms by which exposure to stressful stimuli alters central circuits that mediate anxiety-like emotional behavior are still unknown. Substantial evidence has implicated regions of the central extended amygdala, including the bed nucleus of the stria terminalis (BNST) and the central nucle...

  17. Investigating Late Amazonian Volcanotectonic Activity on Olympus Mons, Mars using Flank Vents and Arcuate Graben

    Science.gov (United States)

    Peters, S.; Christensen, P. R.

    2015-12-01

    Volcanism, a fundamental process in shaping the Martian surface, is crucial to understanding its evolution. Olympus Mons, the largest volcano on Mars, is one of several large shield volcanoes. Previous studies were technologically limited to large features associated with these constructs. With the advent of high resolution datasets, we are now able to investigate smaller features, such as flank vents and arcuate graben. Flank vents, common on polygenetic volcanoes, indicate that magma has propagated away from the main conduit and/or magma chamber. Vent morphology allows for the characterization of magma properties and eruption rates. Graben indicate extensional deformation. The distribution of graben provides information on stresses that acted on the volcano. In lieu of geophysical, spectral and in-situ data, morphology, morphometry and spatial relationships are powerful tools. We utilized high resolution image data (CTX, HiRISE and THEMIS IR) and topographic data (HRSC DTM, MOLA) to identify and characterize flank vents and graben. We observed 60 flank vents and 84 arcuate graben on Olympus Mons. Flank vents display varying morphologies and morphometries, suggesting different eruption styles and variable magma volatility. Vents occur primarily on the lower flank. This suggests magma has propagated substantial distances from the magma chamber. Observed clustering of vents may also indicate shallow magma sources. Similarly, graben are observed on the lower flank crosscutting young lava flows that have mantled portions of the escarpment. This indicates either gravitational spreading of Olympus Mons or flexure of the lithosphere in response to the load of the edifice. Collectively, the distribution of flank vents and arcuate graben suggests a similar development to that proposed for Ascraeus Mons. Based on superposition relationships and dates from previous studies, the flank vents and graben formed in the Late Amazonian (≤500 Ma).

  18. Investigation of the (232)Th Nucleus Excitations at the FEL {gamma} - Nucleus Colliders

    CERN Document Server

    Koru, H; Sultansoy, S F; Sarer, B

    2001-01-01

    The physics search potential of the FEL {gamma} - Nucleus colliders is analysed using excitations of the (232)Th nucleus. It is shown that, due to the monochromacity of FEL {gamma} beam and high statistics, proposed colliders will play an important role in the field of "traditional" nuclear physics.

  19. Nucleus-associated microtubules help determine the division plane of plant epidermal cells: avoidance of four-way junctions and the role of cell geometry.

    Science.gov (United States)

    Flanders, D J; Rawlins, D J; Shaw, P J; Lloyd, C W

    1990-04-01

    To investigate the spatial relationship between the nucleus and the cortical division site, epidermal cells were selected in which the separation between these two areas is large. Avoiding enzyme treatment and air drying, Datura stramonium cells were labeled with antitubulin antibodies and the three-dimensional aspect of the cytoskeletons was reconstructed using computer-aided optical sectioning. In vacuolated cells preparing for division, the nucleus migrates into the center of the cell, suspended by transvacuolar strands. These strands are now shown to contain continuous bundles of microtubules which bridge the nucleus to the cortex. These nucleus-radiating microtubules adopt different configurations in cells of different shape. In elongated cells with more or less parallel side walls, oblique strands radiating from the nucleus to the long side walls are presumably unstable, for they are progressively realigned into a transverse disc (the phragmosome) as broad, cortical, preprophase bands (PPBs) become tighter. The phragmosome and the PPB are both known predictors of the division plane and our observations indicate that they align simultaneously in elongated epidermal cells. These observations suggest another hypothesis: that the PPB may contain microtubules polymerized from the nuclear surface. In elongated cells, the majority of the radiating microtubules, therefore, come to anchor the nucleus in the transverse plane, consistent with the observed tendency of such cells to divide perpendicular to the long axis. In nonrectangular isodiametric epidermal cells, which approximate regular hexagons in section, the radial microtubular strands emanating from the nucleus tend to remain associated with the middle of each subtending cell wall. The strands are not reorganized into a single dominant transverse bar, but remain as a starlike array until mitosis. PPBs in these cells are not as tight; they may only be a sparse accumulation of microtubules, even forming along non

  20. Arcuate sign of posterolateral knee injuries: anatomic, radiographic, and MR imaging data related to patterns of injury

    International Nuclear Information System (INIS)

    The ''arcuate sign'' is considered a pathognomonic sign for injuries of the posterolateral (PL) corner of the knee. The purpose of our study was to identify different patterns of injury to the fibular head that may associate with injuries to specific ligaments and tendons of the PL corner of the knee. The anatomic relations between the insertions of fibular collateral ligament (FCL), biceps femoris tendon (BFT), popliteofibular ligament (PFL), and arcuate ligament in normal cadaveric knees were also investigated. Magnetic resonance imaging was performed in two cadaveric knees which subsequently were dissected. Radiopaque markers were placed upon the fibular insertions of the FCL, BFT, PFL, and arcuate ligament in the dissected knees, and knee radiographs were then obtained. Twelve patients with radiographic or MR imaging evidence of isolated injury to the PL corner of the knee were retrospectively reviewed, with regard to avulsion fractures and marrow edema in the fibular head and the integrity of the ligaments of the PL corner of the knee. The PFL and arcuate ligament were seen to attach directly to the posterior and medial aspect of the styloid process of the fibular head. The FCL and BFT attached as a conjoined structure on the lateral aspect of the fibular head lateral, anterior and inferior to the attachment site of the PFL and arcuate ligament. Injury to the arcuate ligament or PFL was diagnosed in 8 patients who presented with a small avulsion fracture of the styloid process of the fibula (n=2), bone marrow edema in the medial aspect of the fibular head (n=3), or both (n=3). In 4 patients with injury to the conjoined tendon or FCL, a larger avulsion fragment and more diffuse proximal fibular edema were seen. Radiographic and MR imaging findings in injuries of the posterolateral corner of the knee may suggest injury to specific structures inserting in the fibular head. (orig.)

  1. A Combined fMRI and DTI Examination of Functional Language Lateralization and Arcuate Fasciculus Structure: Effects of Degree versus Direction of Hand Preference

    Science.gov (United States)

    Propper, Ruthe E.; O'Donnell, Lauren J.; Whalen, Stephen; Tie, Yanmei; Norton, Isaiah H.; Suarez, Ralph O.; Zollei, Lilla; Radmanesh, Alireza; Golby, Alexandra J.

    2010-01-01

    The present study examined the relationship between hand preference degree and direction, functional language lateralization in Broca's and Wernicke's areas, and structural measures of the arcuate fasciculus. Results revealed an effect of degree of hand preference on arcuate fasciculus structure, such that consistently-handed individuals,…

  2. Role of Nesfatin-1 in the Reproductive Axis of Male Rat

    Science.gov (United States)

    Gao, Xiaoxiao; Zhang, Kaifa; Song, Min; Li, Xiumei; Luo, Lei; Tian, Yuan; Zhang, Yunhai; Li, Yunsheng; Zhang, Xiaorong; Ling, Yinghui; Fang, Fugui; Liu, Ya

    2016-01-01

    Nesfatin-1 is an important molecule in the regulation of reproduction. However, its role in the reproductive axis in male animals remains to be understood. Here, we found that nesfatin-1 was mainly distributed in the arcuate nucleus (ARC), paraventricular nucleus (PVN), periventricular nucleus (PeN), and lateral hypothalamic area (LHA) of the hypothalamus; adenohypophysis and Leydig cells in male rats. Moreover, the concentrations of serum nesfatin-1 and its mRNA in hypothalamo-pituitary-gonadal axis (HPGA) vary with the age of the male rat. After intracerebroventricular injection of nesfatin-1, the hypothalamic genes for gonadotrophin releasing hormone (GnRH), kisspeptin (Kiss-1), pituitary genes for follicle-stimulate hormone β(FSHβ), luteinizing hormone β(LHβ), and genes for testicular steroidogenic acute regulatory (StAR) expression levels were decreased significantly. Nesfatin-1 significantly increased the expression of genes for 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), and cytochrome P450 cleavage (P450scc) in the testis of pubertal rats, but their levels decreased in adult rats (P < 0.05), along with the serum FSH, LH, and testosterone (T) concentrations. After nesfatin-1 addition in vitro, T concentrations of the supernatant were significantly higher than that in the control group. These results were suggestive of the role of nesfatin-1 in the regulation of the reproductive axis in male rats. PMID:27599613

  3. Role of Nesfatin-1 in the Reproductive Axis of Male Rat.

    Science.gov (United States)

    Gao, Xiaoxiao; Zhang, Kaifa; Song, Min; Li, Xiumei; Luo, Lei; Tian, Yuan; Zhang, Yunhai; Li, Yunsheng; Zhang, Xiaorong; Ling, Yinghui; Fang, Fugui; Liu, Ya

    2016-01-01

    Nesfatin-1 is an important molecule in the regulation of reproduction. However, its role in the reproductive axis in male animals remains to be understood. Here, we found that nesfatin-1 was mainly distributed in the arcuate nucleus (ARC), paraventricular nucleus (PVN), periventricular nucleus (PeN), and lateral hypothalamic area (LHA) of the hypothalamus; adenohypophysis and Leydig cells in male rats. Moreover, the concentrations of serum nesfatin-1 and its mRNA in hypothalamo-pituitary-gonadal axis (HPGA) vary with the age of the male rat. After intracerebroventricular injection of nesfatin-1, the hypothalamic genes for gonadotrophin releasing hormone (GnRH), kisspeptin (Kiss-1), pituitary genes for follicle-stimulate hormone β(FSHβ), luteinizing hormone β(LHβ), and genes for testicular steroidogenic acute regulatory (StAR) expression levels were decreased significantly. Nesfatin-1 significantly increased the expression of genes for 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), and cytochrome P450 cleavage (P450scc) in the testis of pubertal rats, but their levels decreased in adult rats (P < 0.05), along with the serum FSH, LH, and testosterone (T) concentrations. After nesfatin-1 addition in vitro, T concentrations of the supernatant were significantly higher than that in the control group. These results were suggestive of the role of nesfatin-1 in the regulation of the reproductive axis in male rats. PMID:27599613

  4. Photon Exchange in Nucleus-Nucleus Collisions

    OpenAIRE

    Bertulani, Carlos A.

    2002-01-01

    The strong electromagnetic fields in peripheral heavy ion collisions give rise to photon-photon and photon-nucleus interactions. I present a general survey of the photon-photon and photon-hadron physics accessible in these collisions. Among these processes I discuss the nuclear fragmentation through the excitation of giant resonances, the Coulomb dissociation method for application in nuclear astrophysics, and the production of particles.

  5. A review of the arcuate structures in the Iberian Variscides; constraints and genetic models

    Science.gov (United States)

    Dias, R.; Ribeiro, A.; Romão, J.; Coke, C.; Moreira, N.

    2016-06-01

    The main Ibero-Armorican Arc (IAA) is essentially defined by a predominant NW-SE trend in the Iberian branch and an E-W trend in the Brittany one. However, in northern Spain it presents a 180° rotation, sometimes known as the Cantabrian Arc (CA). The relation between both arcs is controversial, being considered either as a single arc due to one tectonic event, or as the result of a polyphasic process. According to the last assumption, there is a later arcuate structure (CA), overlapping a previous major one (IAA). Whatever the models, they must be able to explain the presence of a Variscan sinistral transpression in Iberia and a dextral one in Armorica, and a deformation spanning from the Devonian to the Upper Carboniferous. Another arcuate structure, in continuity with the CA, the Central-Iberian Arc (CIA) was recently proposed mainly based upon on magnetic anomalies, geometry of major folds and Ordovician paleocurrents. The critical review of the structural, stratigraphic and geophysical data supports both the IAA and the CA, but as independent structures. However, the presence of a CIA is highly questionable and could not be supported. The complex strain pattern of the IAA and the CA could be explained by a Devonian - Carboniferous polyphasic indentation of a Gondwana promontory. In this model the CA is essentially a thin-skinned arc, while the IAA has a more complex and longer evolution that has led to a thick-skinned first order structure. Nevertheless, both arcs are essentially the result of a lithospheric bending process during the Iberian Variscides.

  6. Role of the origin of glutamatergic synaptic inputs in controlling synaptic plasticity and its modulation by alcohol in mice nucleus accumbens

    Directory of Open Access Journals (Sweden)

    Gilles Erwann Martin

    2015-07-01

    Full Text Available It is widely accepted that long-lasting changes of synaptic strength in the nucleus accumbens, a brain region involved in drug reward, mediate acute and chronic effects of alcohol. However, our understanding of the mechanisms underlying the effects of alcohol on synaptic plasticity is limited by the fact that the nucleus accumbens receives glutamatergic inputs from distinct brain regions (e.g. the prefrontal cortex, the amygdala and the hippocampus, each region providing different information (e.g. spatial, emotional and cognitive. Combining whole-cell patch-clamp recordings and the optogenetic technique, we examined synaptic plasticity, and its regulation by alcohol, at cortical, hippocampal and amygdala inputs in fresh slices of mouse tissue. We showed that the origin of synaptic inputs determines the basic properties of glutamatergic synaptic transmission, the expression of spike-timing dependent long-term depression (tLTD and long-term potentiation (tLTP and their regulation by alcohol. While we observed both tLTP and tLTD at amygadala and hippocampal synapses, we showed that cortical inputs only undergo tLTD. Functionally, we provide evidence that acute EtOH has little effects on higher order information coming from the prefrontal cortex (PFCx, while severely impacting the ability of emotional and contextual information to induce long-lasting changes of synaptic strength.

  7. Cross-talk between metabolism and reproduction: The role of POMC and SF1 neurons

    Science.gov (United States)

    Energy homeostasis and reproduction require tight coordination, but the mechanisms underlying their interaction are not fully understood. Two sets of hypothalamic neurons, namely pro-opiomelanocortin (POMC) neurons in the arcuate nucleus and steroidogenic factor-1 (SF1) neurons in the ventromedial h...

  8. Effects of Peripheral Neurotensin on Appetite Regulation and Its Role in Gastric Bypass Surgery

    DEFF Research Database (Denmark)

    Ratner, Cecilia; Skov, Louise J; Raida, Zindy;

    2016-01-01

    increased proopiomelanocortin mRNA in the arcuate nucleus. We also investigated the importance of NT for the decreased food intake after gastric bypass surgery in a rat model of Roux-en-Y gastric bypass (RYGB). NT was increased in plasma and in the gastrointestinal tract in RYGB rats, and pharmacological...

  9. Title: Sex differences in stress-induced social withdrawal: role of brain derived neurotrophic factor in the bed nucleus of the stria terminalis

    Directory of Open Access Journals (Sweden)

    Gian David Greenberg

    2014-01-01

    Full Text Available Depression and anxiety disorders are more common in women than men, and little is known about the neurobiological mechanisms that contribute to this disparity. Recent data suggest that stress-induced changes in neurotrophins have opposing effects on behavior by acting in different brain networks. Social defeat has been an important approach for understanding neurotrophin action, but low female aggression levels in rats and mice have limited the application of these methods primarily to males. We examined the effects of social defeat in monogamous California mice (Peromyscus californicus, a species in which both males and females defend territories. We demonstrate that defeat stress increases mature brain-derived neurotrophic factor (BDNF protein but not mRNA in the bed nucleus of the stria terminalis (BNST in females but not males. Changes in BDNF protein were limited to anterior subregions of the BNST, and there were no changes in the adjacent nucleus accumbens (NAc. The effects of defeat on social withdrawal behavior and BDNF were reversed by chronic, low doses of the antidepressant sertraline. However, higher doses of sertraline restored social withdrawal and elevated BDNF levels. Acute treatment with a low dose of sertraline failed to reverse the effects of defeat. Infusions of the selective tyrosine-related kinase B receptor (TrkB antagonist ANA-12 into the anterior BNST specifically increased social interaction in stressed females but had no effect on behavior in females naïve to defeat. These results suggest that stress-induced increases in BDNF in the anterior BNST contribute to the exaggerated social withdrawal phenotype observed in females.

  10. Hypertrophic degeneration of the inferior olivary nucleus impacts perception of gravity

    Directory of Open Access Journals (Sweden)

    Alexander A Tarnutzer

    2012-05-01

    Full Text Available Interruption of the Guillain-Mollaret triangle interconnecting the red nucleus, the inferior olivary nucleus and the contralateral dentate nucleus is predicted to interfere with the dentate nucleus’ role in estimating direction of gravity. In a patient with pendular nystagmus due to hypertrophic inferior olivary nucleus degeneration secondary to ponto-mesencephalic hemorrhage, perceived vertical shifted from clockwise to counter-clockwise deviations within 4 months. We hypothesize that synchronized oscillations of inferior olivary nucleus neurons induce a loss of inhibitory control, leading to hyperactivity of the contralateral dentate nucleus and, as a result, to perceived vertical roll-tilt to the side of the overactive dentate nucleus.

  11. Laparoscopic Division of Median Arcuate Ligament for the Celiac Axis Compression Syndrome-Two Case Reports with Review of Literature.

    Science.gov (United States)

    Ramakrishnan, Parthasarathy; Deuri, Biswajit; Keerthi, M S S; Naidu, Subrahmaneswara Babu; Subbaiah, Rajapandian; Raj, Praveen; Palanisamy, Senthilnathan; Chinnusamy, Palanivelu

    2016-04-01

    Median arcuate ligament (MAL) syndrome is an uncommon condition caused by the external compression of the celiac trunk by the median arcuate ligament. In the current era of technological advancement, this syndrome may be corrected through the laparoscopic approach. We report two patients who were diagnosed as MAL syndrome and underwent laparoscopic division of MAL fibers at our institute. Both the patients improved symptomatically following the procedure and were discharged on the fourth post-operative day. Also, they remained symptom free during subsequent follow-up period of 1 year and 8 months, respectively. Laparoscopic approach to correct the MAL syndrome is feasible and safe. It may be the preferred modality of treatment in view of its superior visualization and lack of morbidity. However, adequate experience in advanced laparoscopic surgery is required before attempting this procedure.

  12. Developmental process of the arcuate fasciculus from infancy to adolescence: a diffusion tensor imaging study

    Directory of Open Access Journals (Sweden)

    Hyeong Jun Tak

    2016-01-01

    Full Text Available We investigated the radiologic developmental process of the arcuate fasciculus (AF using subcomponent diffusion tensor imaging (DTI analysis in typically developing volunteers. DTI data were acquired from 96 consecutive typically developing children, aged 0-14 years. AF subcomponents, including the posterior, anterior, and direct AF tracts were analyzed. Success rates of analysis (AR and fractional anisotropy (FA values of each subcomponent tract were measured and compared. AR of all subcomponent tracts, except the posterior, showed a significant increase with aging (P < 0.05. Subcomponent tracts had a specific developmental sequence: First, the posterior AF tract, second, the anterior AF tract, and last, the direct AF tract in identical hemispheres. FA values of all subcomponent tracts, except right direct AF tract, showed correlation with subject′s age (P < 0.05. Increased AR and FA values were observed in female subjects in young age (0-2 years group compared with males (P < 0.05. The direct AF tract showed leftward hemispheric asymmetry and this tendency showed greater consolidation in older age (3-14 years groups (P < 0.05. These findings demonstrated the radiologic developmental patterns of the AF from infancy to adolescence using subcomponent DTI analysis. The AF showed a specific developmental sequence, sex difference in younger age, and hemispheric asymmetry in older age.

  13. Arcuate fasciculus abnormalities and their relationship with psychotic symptoms in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Muhammad Farid Abdul-Rahman

    Full Text Available Disruption of fronto-temporal connections involving the arcuate fasciculus (AF may underlie language processing anomalies and psychotic features such as auditory hallucinations in schizophrenia. No study to date has specifically investigated abnormalities of white matter integrity at particular loci along the AF as well as its regional lateralization in schizophrenia. We examined white matter changes (fractional anisotropy (FA, axial diffusivity (AD, asymmetry indices along the whole extent of the AF and their relationship with psychotic symptoms in 32 males with schizophrenia and 44 healthy males. Large deformation diffeomorphic metric mapping and Fiber Assignment Continuous Tracking were employed to characterize FA and AD along the geometric curve of the AF. Our results showed that patients with schizophrenia had lower FA in the frontal aspects of the left AF compared with healthy controls. Greater left FA and AD lateralization in the temporal segment of AF were associated with more severe positive psychotic symptoms such as delusions and hallucinations in patients with schizophrenia. Disruption of white matter integrity of the left frontal AF and accentuation of normal left greater than right asymmetry of FA/AD in the temporal AF further support the notion of aberrant fronto-temporal connectivity in schizophrenia. AF pathology can affect corollary discharge of neural signals from frontal speech/motor initiation areas to suppress activity of auditory cortex that may influence psychotic phenomena such as auditory hallucinations and facilitate elaboration of delusional content.

  14. Prolonged exposure to a Mer ligand in leukemia: Gas6 favors expression of a partial Mer glycoform and reveals a novel role for Mer in the nucleus.

    Directory of Open Access Journals (Sweden)

    Justine Migdall-Wilson

    Full Text Available Mer tyrosine kinase is ectopically expressed in acute lymphoblastic leukemia and associated with enhanced chemoresistance and disease progression. While such effects are generally ascribed to increased engagement of oncogenic pathways downstream of Mer stimulation by its ligand, Gas6, Mer has not been characterized beyond the scope of its signaling activity. The present study explores Mer behavior following prolonged exposure to Gas6, a context similar to the Gas6-enriched microenvironment of the bone marrow, where a steady supply of ligand facilitates continuous engagement of Mer and likely sustains the presence of leukemic cells. Long-term Gas6 exposure induced production of a partially N-glycosylated form of Mer from newly synthesized stores of protein. Preferential expression of the partial Mer glycoform was associated with diminished levels of Mer on the cell surface and altered Mer localization within the nuclear-soluble and chromatin-bound fractions. The presence of Mer in the nucleus is a novel finding for this receptor, and the glycoform-specific preferences observed in each nuclear compartment suggest that glycosylation may influence Mer function within particular subcellular locales. Previous studies have established Mer as an attractive cancer biologic target, and understanding the complexity of its activity has important implications for potential strategies of Mer inhibition in leukemia therapy. Our results identify several novel features of Mer that expand the breadth of its functions and impact the development of therapeutic modalities designed to target Mer.

  15. A pericentrin-related protein homolog in Aspergillus nidulans plays important roles in nucleus positioning and cell polarity by affecting microtubule organization.

    Science.gov (United States)

    Chen, Peiying; Gao, Rongsui; Chen, Shaochun; Pu, Li; Li, Pin; Huang, Ying; Lu, Ling

    2012-12-01

    Pericentrin is a large coiled-coil protein in mammalian centrosomes that serves as a multifunctional scaffold for anchoring numerous proteins. Recent studies have linked numerous human disorders with mutated or elevated levels of pericentrin, suggesting unrecognized contributions of pericentrin-related proteins to the development of these disorders. In this study, we characterized AnPcpA, a putative homolog of pericentrin-related protein in the model filamentous fungus Aspergillus nidulans, and found that it is essential for conidial germination and hyphal development. Compared to the hyphal apex localization pattern of calmodulin (CaM), which has been identified as an interactive partner of the pericentrin homolog, GFP-AnPcpA fluorescence dots are associated mainly with nuclei, while the accumulation of CaM at the hyphal apex depends on the function of AnPcpA. In addition, the depletion of AnPcpA by an inducible alcA promoter repression results in severe growth defects and abnormal nuclear segregation. Most interestingly, in mature hyphal cells, knockdown of pericentrin was able to significantly induce changes in cell shape and cytoskeletal remodeling; it resulted in some enlarged compartments with condensed nuclei and anucleate small compartments as well. Moreover, defects in AnPcpA significantly disrupted the microtubule organization and nucleation, suggesting that AnPcpA may affect nucleus positioning by influencing microtubule organization.

  16. The Neuronal Transition Probability (NTP) Model for the Dynamic Progression of Non-REM Sleep EEG: The Role of the Suprachiasmatic Nucleus

    CERN Document Server

    Merica, H

    2011-01-01

    Little attention has gone into linking to its neuronal substrates the dynamic structure of non-rapid-eye-movement (NREM) sleep, defined as the pattern of time-course power in all frequency bands across an entire episode. Using the spectral power time-courses in the sleep electroencephalogram (EEG), we showed in the typical first episode, several moves towards-and-away from deep sleep, each having an identical pattern linking the major frequency bands beta, sigma and delta. The neuronal transition probability model (NTP) - in fitting the data well - successfully explained the pattern as resulting from stochastic transitions of the firing-rates of the thalamically-projecting brainstem-activating neurons, alternating between two steady dynamic-states (towards-and-away from deep sleep) each initiated by a so-far unidentified flip-flop. The aims here are to identify this flip-flop and to demonstrate that the model fits well all NREM episodes, not just the first. Using published data on suprachiasmatic nucleus (SCN...

  17. Enhancement of φ Mesons in Relativistic Nucleus-Nucleus Collisions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The фmeson production in relativistic nucleus-nucleus collisions is investigated systematically usinga hadron-string cascade model LUCIAE. Within the framework of the model and relying on the collective

  18. Leptin receptor immunoreactivity is present in ascending serotonergic and catecholaminergic neurons of the rat

    DEFF Research Database (Denmark)

    Hay-Schmidt, Anders; Helboe, Lone; Larsen, Philip J.

    2001-01-01

    Obesity, tyrosine hydroxylase, arcuate nucleus, paracentricular nucleus, raphe nuclei, leptin, serotonin, catecholamines......Obesity, tyrosine hydroxylase, arcuate nucleus, paracentricular nucleus, raphe nuclei, leptin, serotonin, catecholamines...

  19. NMDA receptors regulate nicotine-enhanced brain reward function and intravenous nicotine self-administration: role of the ventral tegmental area and central nucleus of the amygdala.

    Science.gov (United States)

    Kenny, Paul J; Chartoff, Elena; Roberto, Marisa; Carlezon, William A; Markou, Athina

    2009-01-01

    Nicotine is considered an important component of tobacco responsible for the smoking habit in humans. Nicotine increases glutamate-mediated transmission throughout brain reward circuitries. This action of nicotine could potentially contribute to its intrinsic rewarding and reward-enhancing properties, which motivate consumption of the drug. Here we show that the competitive N-methyl-D-aspartate (NMDA) receptor antagonist LY235959 (0.5-2.5 mg per kg) abolished nicotine-enhanced brain reward function, reflected in blockade of the lowering of intracranial self-stimulation (ICSS) thresholds usually observed after experimenter-administered (0.25 mg per kg) or intravenously self-administered (0.03 mg per kg per infusion) nicotine injections. The highest LY235959 dose (5 mg per kg) tested reversed the hedonic valence of nicotine from positive to negative, reflected in nicotine-induced elevations of ICSS thresholds. LY235959 doses that reversed nicotine-induced lowering of ICSS thresholds also markedly decreased nicotine self-administration without altering responding for food reinforcement, whereas the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor antagonist NBQX had no effects on nicotine intake. In addition, nicotine self-administration upregulated NMDA receptor subunit expression in the central nucleus of the amygdala (CeA) and ventral tegmental area (VTA), suggesting important interactions between nicotine and the NMDA receptor. Furthermore, nicotine (1 microM) increased NMDA receptor-mediated excitatory postsynaptic currents in rat CeA slices, similar to its previously described effects in the VTA. Finally, infusion of LY235959 (0.1-10 ng per side) into the CeA or VTA decreased nicotine self-administration. Taken together, these data suggest that NMDA receptors, including those in the CeA and VTA, gate the magnitude and valence of the effects of nicotine on brain reward systems, thereby regulating motivation to consume the drug.

  20. The role of ghrelin, leptin and insulin in foetal development

    Directory of Open Access Journals (Sweden)

    Magdalena Warchoł

    2014-06-01

    Full Text Available introduction and objective. The growing epidemic of childhood obesity has forced scientists to search for methods to prevent feeding disorders. Increasing interest in appetite regulating hormones has revealed their influence on energy homeostasis after birth or even in[i] utero[/i]. state of knowledge. The presence of ghrelin in the stomach of human foetuses and the distinctive production in the pancreas of neonates suggests the role of ghrelin in pre- and post-natal development. The neonatal period appears to be a critical time for the formation of adipose tissue-hypothalamus circuits, thus the amount of adipocytes in foetal life may be a major regulator of food intake. Insulin’s orexigenic effect in the arcuate nucleus of the hypothalamus can be a major modulator of foetal development. objective. This review, based on available literature, aims to analyses the role of appetite regulating hormones in foetal development. summary. Different concentrations of hormones, such as ghrelin, leptin and insulin during foetal life raises the question whether or not they can be modulated, thereby avoiding obesity before birth. Children with pancreas agenesis showed smaller body size at birth, which emphasises the probable role of insulin in foetal growth. Study of sheep foetuses with IUGR confirmed these finding. Appetite-regulating hormones show different roles in foetal development and seem to be essential in the perinatal period.

  1. Neutrino nucleus cross sections

    CERN Document Server

    Athar, M Sajjad; Singh, S K; Vacas, M J Vicente

    2008-01-01

    We present the results of our calculation which has been performed to study the nuclear effects in the quasielastic, inelastic and deep inelastic scattering of neutrinos(antineutrinos) from nuclear targets. These calculations are done in the local density approximation. We take into account the effect of Pauli blocking, Fermi motion, Coulomb effect, renormalization of weak transition strengths in the nuclear medium in the case of the quasielastic reaction. The inelastic reaction leading to production of pions is calculated in a $\\Delta $- dominance model taking into account the renormalization of $\\Delta$ properties in the nuclear medium and the final state interaction effects of the outgoing pions with the residual nucleus. We discuss the nuclear effects in the $F_{3}^{A}(x)$ structure function in the deep inelastic neutrino(antineutrino) reaction using a relativistic framework to describe the nucleon spectral function in the nucleus.

  2. The Role of PVH Circuits in Leptin Action and Energy Balance.

    Science.gov (United States)

    Sutton, Amy K; Myers, Martin G; Olson, David P

    2016-01-01

    Although it has been known for more than a century that the brain controls overall energy balance and adiposity by regulating feeding behavior and energy expenditure, the roles for individual brain regions and neuronal subtypes were not fully understood until recently. This area of research is active, and as such our understanding of the central regulation of energy balance is continually being refined as new details emerge. Much of what we now know stems from the discoveries of leptin and the hypothalamic melanocortin system. Hypothalamic circuits play a crucial role in the control of feeding and energy expenditure, and within the hypothalamus, the arcuate nucleus (ARC) functions as a gateway for hormonal signals of energy balance, such as leptin. It is also well established that the ARC is a primary residence for hypothalamic melanocortinergic neurons. The paraventricular hypothalamic nucleus (PVH) receives direct melanocortin input, along with other integrated signals that affect energy balance, and mediates the majority of hypothalamic output to control both feeding and energy expenditure. Herein, we review in detail the structure and function of the ARC-PVH circuit in mediating leptin signaling and in regulating energy balance. PMID:26863324

  3. Polarized Proton Nucleus Scattering

    OpenAIRE

    Kopeliovich, B. Z.; Trueman, T. L.

    2000-01-01

    We show that, to a very good approximation, the ratio of the spin-flip to the non-flip parts of the elastic proton-nucleus amplitude is the same as for proton-nucleon scattering at very high energy. The result is used to do a realistic calculation of the analyzing power A_N for pC scattering in the Coulomb-nuclear interference (CNI) region of momentum transfer.

  4. Hadron nucleus interactions

    International Nuclear Information System (INIS)

    The elastic and inelastic scattering of intermediate energy (less than or equal to 1 GeV) protons by nuclei is considered first. The discussion focuses on the determination of the proton-nucleus optical potential in terms of the elementary nucleon-nucleon scattering amplitudes and the properties of the target and residual nucleus. The result is a series of terms for the optical potential. Then the interaction of pions with nuclei for energies in the neighborhood of the Δ-resonance is discussed. In this energy domain an incident pion will with high probability be absorbed by a nucleon to produce the Δ-resonance and thus form a Δ-particle hole state in the nucleus. Next, the subject of hypernuclei is taken up. The Λ hypernuclei and a recently observed Σ hypernuclei comprise situations in which the core nucleus can be probed by a baryon of roughly the same mass as a nucleon, with similar albeit not identical interactions with nucleons. But the Λ (or Σ) does not need to satisfy the Pauli exclusion principle with respect to the nucleons, and therefore can be in orbits forbidden to it if it were a nucleon. As the energy of the projectile increases, it becomes correspondingly more important to take relativistic effects into account. The importance of these effects is strikingly revealed by experiments involving the collision of ultrarelativistic hadrons, protons, pions, kaons (up to Fermilab energies) with nuclei. This phenomenon forms part of the final topic, which includes as well as the collision of relativistic heavy ion projectiles with nuclei. A nuclear Weiszaecker-Williams method developed for dealing with peripheral collisions is described. 32 figures, 10 tables

  5. Antinucleon-nucleus interactions

    Energy Technology Data Exchange (ETDEWEB)

    Dover, C.B.

    1987-01-01

    Recent experimental and theoretical results on anti p-nucleus interactions are reviewed. We focus on determinations of the anti p optical potential from elastic scattering, the use of (anti p, anti p') inelastic scattering to reveal aspects of the spin-isospin dependence of N anti N amplitudes, and some puzzling features of (anti p, anti n) charge exchange reactions on nuclei. 47 refs., 7 figs.

  6. Role of angiotensin II and vasopressin receptors within the supraoptic nucleus in water and sodium intake induced by the injection of angiotensin II into the medial septal area

    Directory of Open Access Journals (Sweden)

    Antunes V.R.

    1998-01-01

    Full Text Available In this study we investigated the effects of the injection into the supraoptic nucleus (SON of non-peptide AT1- and AT2-angiotensin II (ANG II receptor antagonists, DuP753 and PD123319, as well as of the arginine-vasopressin (AVP receptor antagonist d(CH25-Tyr(Me-AVP, on water and 3% NaCl intake induced by the injection of ANG II into the medial septal area (MSA. The effects on water or 3% NaCl intake were assessed in 30-h water-deprived or in 20-h water-deprived furosemide-treated adult male rats, respectively. The drugs were injected in 0.5 ml over 30-60 s. Controls were injected with a similar volume of 0.15 M NaCl. Antagonists were injected at doses of 20, 80 and 180 nmol. Water and sodium intake was measured over a 2-h period. Previous administration of the AT1 receptor antagonist DuP753 into the SON decreased water (65%, N = 10, P<0.01 and sodium intake (81%, N = 8, P<0.01 induced by the injection of ANG II (10 nmol into the MSA. Neither of these responses was significantly changed by injection of the AT2-receptor antagonist PD123319 into the SON. On the other hand, while there was a decrease in water intake (45%, N = 9, P<0.01, ANG II-induced sodium intake was significantly increased (70%, N = 8, P<0.01 following injection of the V1-type vasopressin antagonist d(CH25-Tyr(Me-AVP into the SON. These results suggest that both AT1 and V1 receptors within the SON may be involved in water and sodium intake induced by the activation of ANG II receptors within the MSA. Furthermore, they do not support the involvement of MSA AT2 receptors in the mediation of these responses.

  7. Arcuate fasciculus asymmetry has a hand in language function but not handedness.

    Science.gov (United States)

    Allendorfer, Jane B; Hernando, Kathleen A; Hossain, Shyla; Nenert, Rodolphe; Holland, Scott K; Szaflarski, Jerzy P

    2016-09-01

    The importance of relationships between handedness, language lateralization and localization, and white matter tracts for language performance is unclear. The goal of the study was to investigate these relationships by examining arcuate fasciculus (AF) structural asymmetry (DTI) and functional asymmetry (fMRI) in language circuits, handedness, and linguistic performance. A large sample of right-handed (n = 158) and atypical-handed (n = 82) healthy adults underwent DTI at 3 T to assess number of streamlines and fractional anisotropy (FA) of the AF, and language fMRI. Language functions were assessed using standard tests of vocabulary, naming, verbal fluency, and complex ideation. Laterality indices (LIs) illustrated degree of asymmetry and lateralization patterns for the AF (streamlines and FA) and verb generation fMRI. Both handedness groups showed leftward lateralization bias for streamline and fMRI LIs and symmetry for FA LI. The proportion of subjects with left, right, or symmetric lateralization were similar between groups if based on AF LIs, but differed if based on fMRI LIs (p = 0.0016). Degree of right-handedness was not associated with AF lateralization, but was associated with fMRI language lateralization (p = 0.0014). FA LI was not associated with performance on language assessments, but streamline LI was associated with better vocabulary and complex ideation performance in atypical-handed subjects (p = 0.022 and p = 0.0098, respectively), and better semantic fluency in right-handed subjects (p = 0.047); however, these did not survive multiple comparisons correction. We provide evidence that AF asymmetry is independent of hand preference, and while degree of right-handedness is associated with hemispheric language lateralization, the majority of atypical-handed individuals are left-lateralized for language. Hum Brain Mapp 37:3297-3309, 2016. © 2016 Wiley Periodicals, Inc.

  8. Seasonal shoreline behaviours along the arcuate Niger Delta coast: Complex interaction between fluvial and marine processes

    Science.gov (United States)

    Dada, Olusegun A.; Li, Guangxue; Qiao, Lulu; Ding, Dong; Ma, Yanyan; Xu, Jishang

    2016-07-01

    Deltaic coasts are dynamic geomorphic systems where continuous changes occur on diverse spatial and temporal scales, and these changes constitute an important aspect of their evolution. Based on three-year satellite-derived shoreline data coupled with re-analyzed wave data and hydro-meteorological data, a comprehensive analysis of the dominant processes governing the seasonal shoreline changes along the oil-rich arcuate section of the Niger Delta, in the Nigerian Shelf of the North Atlantic Ocean has been undertaken. Shoreline analysis results show that the delta coast is characterized by predominant summer erosion and maximum winter accretion. Between 2010 and 2012, erosion dominated over accretion and a total of 9.1 km2 deltaic land was lost to coastline erosion at an annual average erosion rate of 4.55±1.21 km2/yr. A greater understanding of the dominant factors responsible for the change is presented. Shoreline change interactions with cross-shore sediment exchange processes are prominent at seasonal timescale (Summer R2=-0.85 and Winter R2=0.7), and interannual timescale (R2=-0.93) with longshore sediment transport processes. Correlation analysis reveals a gradual degeneration of relationship between the suspended sediment flux and coastal hydrodynamics beginning from 2010 to 2012 (cross-shore transport, R=0.68, 0.36 and 0.2 for 2010, 2011 and 2012, respectively; longshore transport R=0.63, 0.44 and 0.2 for 2010, 2011 and 2012, respectively). The study concludes that the effect of fluvial sediment reduction to the delta coast due to capital dredging of the Lower Niger River channels between 2009 and 2012, and periodic fluctuations in the nearshore hydrodynamics processes caused the observed annual shoreline erosion that eventually forced the deltaic coastline toward a state of landward migration during the study period.

  9. Dopamine D2-like receptor agonists induce penile erection in male rats: differential role of D2, D3 and D4 receptors in the paraventricular nucleus of the hypothalamus.

    Science.gov (United States)

    Sanna, Fabrizio; Succu, Salvatora; Hübner, Harald; Gmeiner, Peter; Argiolas, Antonio; Melis, Maria Rosaria

    2011-11-20

    Pramipexole, a dopamine D3/D2 receptor agonist, induces penile erection when administered subcutaneously (s.c.) or into the paraventricular nucleus of the hypothalamus of male rats, like apomorphine, a mixed D1/D2 receptor agonist, and PD 168,077, a D4 receptor agonist. A U-inverted dose-response curve was found with pramipexole and apomorphine, but not with PD 168,077 (0.025-0.5mg/kg s.c.). Pramipexole effect was abolished by L-741,626, a D2 receptor antagonist (2.5 and 5mg/kg s.c.) and raclopride, a D2/D3 receptor antagonist (0.025 and 0.1mg/kg s.c.), but not by SB277011A (2.5 and 10mg/kg s.c.) or FAUC 365 (1 and 2mg/kg s.c.), two D3 receptor antagonists, or L-745,870 (1 and 5mg/kg i.p.), a D4 receptor antagonist. Similar results were found with apomorphine (0.08mg/kg s.c.), although its effect was also partially reduced by L-745,870. In contrast, PD 168,077 effect was abolished by L-745,870, but not L-741,626, SB277011A, FAUC 365 or raclopride. Similar results were found when dopamine agonists (5-200ng/rat) and antagonists (1-5μg/rat) were injected into the paraventricular nucleus. However, no U-inverted dose-response curve was found with any of the three dopamine agonists injected into this nucleus. As pramipexole- and apomorphine-induced penile erection was reduced mainly by D2, but not D3 or D4 antagonists, D2 receptors are those that mediate the pro-erectile effect of these dopamine agonists. Although the selective stimulation of paraventricular D4 receptors induces penile erection, D4 receptors seem to play only a modest role in the pro-erectile effect of the above dopamine agonists. PMID:21784104

  10. Neuromedin B and gastrin releasing peptide excite arcuate nucleus neuropeptide Y neurons in a novel transgenic mouse expressing strong renilla GFP in NPY neurons

    OpenAIRE

    van den Pol, Anthony N.; Yao, Yang; Fu, Li-Ying; Foo, Kylie; Huang, Hao; Coppari, Roberto; Lowell, Brad; Broberger, Christian

    2009-01-01

    Neuropeptide Y (NPY) is one of the most widespread neuropeptides in the brain. Transgenic mice were generated that expressed bright renilla GFP in most or all of the known NPY cells in the brain, which otherwise were not identifiable. GFP expression in NPY cells was confirmed with immunocytochemistry and single cell RT-PCR.

  11. Photoperiodic regulation of insulin receptor mRNA and intracellular insulin signaling in the arcuate nucleus of the Siberian hamster, Phodopus sungorus.

    Science.gov (United States)

    Tups, Alexander; Helwig, Michael; Stöhr, Sigrid; Barrett, Perry; Mercer, Julian G; Klingenspor, Martin

    2006-09-01

    During the last 5 years it has been well established that photoperiod-induced changes in body weight in the seasonal hamster, Phodopus sungorus, are accompanied by a marked seasonal cycle in leptin sensitivity. In the present study, we investigated the possible involvement of insulin signaling in seasonal body weight regulation. We analyzed the expression pattern and relative intensity of insulin receptor (IR), phosphatidylinositol 3-kinase (PI3-kinase), and protein tyrosine phosphatase 1B (PTP1B) mRNAs by in situ hybridization in the brains of juvenile female hamsters acclimated to either long- (LD) or short-day length (SD) for 8 wk, with or without superimposed food deprivation for 48 h. Furthermore, the hypothalamic concentration and distribution of phospho-AKT, a marker of PI3-kinase activity was determined by immunoblotting and immunohistochemistry. Eight weeks of acclimation to SD led to a substantial downregulation of IR, PTP1B gene expression, and phospho-AKT concentration in this brain region, whereas PI3-kinase mRNA was unchanged. Food deprivation induced a decrease in PTP1B and a trend toward lowered IR gene expression in LD but not in SD. Additionally, a striking increase in PTP1B gene expression in the thalamus was observed after food deprivation in both photoperiods. The direction of change in neuronal insulin signaling contrasts to the central catabolic nature of this pathway described in other species. SD-induced reduction in insulin signaling may be due to decline in body fat stores mediated by enhanced central leptin sensitivity. Increased anorexigenic tone of leptin may overwrite central insulin signaling to prevent catabolic overdrive.

  12. Differential modulation of arcuate nucleus and mesolimbic gene expression levels by central leptin in rats on short-term high-fat high-sugar diet

    NARCIS (Netherlands)

    van den Heuvel, José K; Eggels, Leslie; Fliers, Eric; Kalsbeek, A.; Adan, Roger A H; la Fleur, Susanne E

    2014-01-01

    OBJECTIVE: Leptin resistance is a common hallmark of obesity. Rats on a free-choice high-fat high-sugar (fcHFHS) diet are resistant to peripherally administered leptin. The aim of this study was to investigate feeding responses to central leptin as well as the associated changes in mRNA levels in hy

  13. Antineutron-nucleus annihilation

    CERN Document Server

    Botta, E

    2001-01-01

    The n-nucleus annihilation process has been studied by the OBELIX experiment at the CERN Low Energy Antiproton Ring (LEAR) in the (50-400) MeV/c projectile momentum range on C, Al, Cu, Ag, Sn, and Pb nuclear targets. A systematic survey of the annihilation cross- section, sigma /sub alpha /(A, p/sub n/), has been performed, obtaining information on its dependence on the target mass number and on the incoming n momentum. For the first time the mass number dependence of the (inclusive) final state composition of the process has been analyzed. Production of the rho vector meson has also been examined. (13 refs).

  14. Nucleus-nucleus potential with shell-correction contribution

    CERN Document Server

    Denisov, V Yu

    2015-01-01

    The full relaxed-density potential between spherical nuclei is considered as a sum of the macroscopic and shell-correction contributions. The macroscopic part of the potential is related to a nucleus-nucleus potential obtained in the framework of the extended Thomas-Fermi approach with the Skyrme and Coulomb forces and the relaxed-density ansatz for evaluation of proton and neutron densities of interacting nuclei. A simple prescription for the shell-correction part of the total potential is discussed. The parameters of the shell-correction and macroscopic parts of the relaxed-density potential are found by fitting the empirical barrier heights of the 89 nucleus-nucleus systems as well as macroscopic potentials evaluated for 1485 nucleus-nucleus systems at 12 distances around touching points.

  15. Higgs-Boson Production in Nucleus-Nucleus Collisions

    Science.gov (United States)

    Norbury, John W.

    1992-01-01

    Cross section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

  16. Role of Dopamine Receptors Subtypes, D1-Like and D2-Like, within the Nucleus Accumbens Subregions, Core and Shell, on Memory Consolidation in the One-Trial Inhibitory Avoidance Task

    Science.gov (United States)

    Manago, Francesca; Castellano, Claudio; Oliverio, Alberto; Mele, Andrea; De Leonibus, Elvira

    2009-01-01

    Recent evidence demonstrated that dopamine within the nucleus accumbens mediates consolidation of both associative and nonassociative memories. However, the specific contribution of the nucleus accumbens subregions, core and shell, and of D1 and D2 receptors subtypes has not been yet clarified. The aim of this study was, therefore, to directly…

  17. Control of nucleus accumbens activity with neurofeedback

    OpenAIRE

    Greer, Stephanie M.; Trujillo, Andrew J.; Glover, Gary H.; Knutson, Brian

    2014-01-01

    The nucleus accumbens (NAcc) plays critical roles in healthy motivation and learning, as well as in psychiatric disorders (including schizophrenia and attention deficit hyperactivity disorder). Thus, techniques that confer control of NAcc activity might inspire new therapeutic interventions. By providing second-to-second temporal resolution of activity in small subcortical regions, functional magnetic resonance imaging (fMRI) can resolve online changes in NAcc activity, which can then be pres...

  18. Dynamical aspects of intermediate-energy nucleus-nucleus collisions. Pt. 4

    International Nuclear Information System (INIS)

    The production of pions in intermediate energy nucleus-nucleus collisions by incoherent nucleon-nucleon collisions is studied within a microscopic quantal phase-space approach. Employing free production rates for the elementary process N+N → π+X experimental data for inclusive pion yields are approximately reproduced from 20-150 MeV/u within the first collision approximation. These results indicate that cooperative phenomena - apart from the time-dependent mean field - seem to play a minor role for energetic particle production even at very low bombarding energy. (orig.)

  19. Music and the nucleus accumbens.

    Science.gov (United States)

    Mavridis, Ioannis N

    2015-03-01

    Music is a universal feature of human societies over time, mainly because it allows expression and regulation of strong emotions, thus influencing moods and evoking pleasure. The nucleus accumbens (NA), the most important pleasure center of the human brain (dominates the reward system), is the 'king of neurosciences' and dopamine (DA) can be rightfully considered as its 'crown' due to the fundamental role that this neurotransmitter plays in the brain's reward system. Purpose of this article was to review the existing literature regarding the relation between music and the NA. Studies have shown that reward value for music can be coded by activity levels in the NA, whose functional connectivity with auditory and frontal areas increases as a function of increasing musical reward. Listening to music strongly modulates activity in a network of mesolimbic structures involved in reward processing including the NA. The functional connectivity between brain regions mediating reward, autonomic and cognitive processing provides insight into understanding why listening to music is one of the most rewarding and pleasurable human experiences. Musical stimuli can significantly increase extracellular DA levels in the NA. NA DA and serotonin were found significantly higher in animals exposed to music. Finally, passive listening to unfamiliar although liked music showed activations in the NA. PMID:25102783

  20. Neurons of human nucleus accumbens

    Directory of Open Access Journals (Sweden)

    Sazdanović Maja

    2011-01-01

    Full Text Available Background/Aim. Nucleus accumbens is a part of the ventral striatum also known as a drug active brain region, especially related with drug addiction. The aim of the study was to investigate the Golgi morphology of the nucleus accumbens neurons. Methods. The study was performed on the frontal and sagittal sections of 15 human brains by the Golgi Kopsch method. We classified neurons in the human nucleus accumbens according to their morphology and size into four types: type I - fusiform neurons; type II - fusiform neurons with lateral dendrite, arising from a part of the cell body; type III - pyramidal-like neuron; type IV - multipolar neuron. The medium spiny neurons, which are mostly noted regarding to the drug addictive conditions of the brain, correspond to the type IV - multipolar neurons. Results. Two regions of human nucleus accumbens could be clearly recognized on Nissl and Golgi preparations each containing different predominant neuronal types. Central part of nucleus accumbens, core region, has a low density of impregnated neurons with predominant type III, pyramidal-like neurons, with spines on secondary branches and rare type IV, multipolar neurons. Contrary to the core, peripheral region, shell of nucleus, has a high density of impregnated neurons predominantly contained of type I and type IV - multipolar neurons, which all are rich in spines on secondary and tertiary dendritic branches. Conclusion. Our results indicate great morphological variability of human nucleus accumbens neurons. This requires further investigations and clarifying clinical significance of this important brain region.

  1. Formation of light particles in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    The principal experimental results on the yield of the light charged particles in nucleus-nucleus collisions at the low and intermediate energies are reviewed. Inclusive spectra of light particles and their coincidences with the characteristic KX-rays, γ-rays, neutrons, projectile-like fragments, other light particles, fission fragments, and evaporation residues are analyzed. The main theoretical models used for the description of the light particle formation are briefly outlined together with their merits and shortcomings. The unsolved problems of fast light particle formation, in particular, and of nucleus-nucleus interaction dynamics, on the whole, are discussed with the outlooks of new experiments able to clear up some of these problems. (author) 144 refs., 40 figs., 2 tabs

  2. Assessment of arcuate fasciculus with diffusion-tensor tractography may predict the prognosis of aphasia in patients with left middle cerebral artery infarcts

    Energy Technology Data Exchange (ETDEWEB)

    Hosomi, Akiko; Nagakane, Yoshinari; Kuriyama, Nagato; Mizuno, Toshiki; Nakagawa, Masanori [Kyoto Prefectural University of Medicine, Department of Neurology, Graduate School of Medical Science, Kyoto (Japan); Yamada, Kei; Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science, Kyoto (Japan)

    2009-09-15

    It is often clinically difficult to assess the severity of aphasia in the earliest stage of cerebral infarction. A method enabling objective assessment of verbal function is needed for this purpose. We examined whether diffusion tensor (DT) tractography is of clinical value in assessing aphasia. Thirteen right-handed patients with left middle cerebral artery infarcts who were scanned within 2 days after stroke onset were enrolled in this study. Magnetic resonance data of ten control subjects were also examined by DT tractography. Based on the severity of aphasia at discharge, patients were divided into two groups: six patients in the aphasic group and seven in the nonaphasic group. Fractional anisotropy (FA) and number of arcuate fasciculus fibers were evaluated. Asymmetry index was calculated for both FA and number of fibers. FA values for the arcuate fasciculus fibers did not differ between hemispheres in either the patient groups or the controls. Number of arcuate fasciculus fibers exhibited a significant leftward asymmetry in the controls and the nonaphasic group but not in the aphasic group. Asymmetry index of number of fibers was significantly lower (rightward) in the aphasic group than in the nonaphasic (P = 0.015) and control (P = 0.005) groups. Loss of leftward asymmetry in number of AF fibers predicted aphasia at discharge with a sensitivity of 0.83 and specificity of 0.86. Asymmetry of arcuate fasciculus fibers by DT tractography may deserve to be assessed in acute infarction for predicting the fate of vascular aphasia. (orig.)

  3. Orogen-parallel mass transport along the arcuate Himalayan front into Nanga Parbat and the western Himalayan syntaxis

    Science.gov (United States)

    Whipp, David; Beaumont, Christopher

    2016-04-01

    Along the length of the Himalayan arc, Quaternary rock exhumation rates are highest in the Himalayan syntaxes at the lateral ends of the arc. In the western Himalayan syntaxis, these rates may exceed 10 mm/a over the past 2 Ma, requiring an additional source of crustal mass into this region to maintain the high-elevation topography. We have previously demonstrated that strain partitioning of oblique convergence can produce a significant orogen-parallel mass flux into the syntaxis of a Himalaya-like orogen and balance the rapid rates of surface denudation. However, the magnitude of this orogen parallel mass flux and whether strain is partitioned across the Himalayan thrust front is affected by the strength of the material bounding and within the Himalayan orogenic wedge, the dip angle of the basal detachment and the convergence obliquity angle γ. Strain partitioning is expected for a finite-length Himalaya-like segmented linear orogen with an obliquity of γ = 30 - 40°, but the obliquity angle in the Himalayan arc varies from 0 at the center of the arc to ˜ 40° in the western Himalayan syntaxis region. Thus, the conditions in which strain partitioning will occur may not be met along much of the length of the arc. Though there is clear evidence of strain partitioning in the Himalaya, preliminary results from 3D numerical geodynamic models of an orogen with an arcuate geometry based on the Himalaya suggest strain partitioning does not occur for the same conditions observed in earlier models of segmented linear orogens or orogens with a smaller arc radius. In those models, the proportion of the orogen length with a high obliquity angle was greater, which favors strain partitioning. In numerical experiments of an arcuate Himalayan orogen with weak material (friction angle φ ≤ 5°) at the back of the orogenic wedge, strain partitioning is only observed in the toe of the orogenic wedge (10-15 km from the thrust front) at the western end of the arc, rather than for

  4. Arcuate fasciculus laterality by diffusion tensor imaging correlates with language laterality by functional MRI in preadolescent children

    Energy Technology Data Exchange (ETDEWEB)

    Sreedharan, Ruma Madhu [Government Medical College Hospital, Department of Radiology, Trivandrum, Kerala (India); Menon, Amitha C.; Thomas, Sanjeev V. [Sree Chitra, Thirunal Institute for Medical Sciences and Technology, Department of Neurology, Thiruvananthapuram, Kerala (India); James, Jija S.; Kesavadas, Chandrasekharan [SCTIMST, Department of Imaging Science and Interventional Radiology, Trivandrum, Kerala (India)

    2015-03-01

    Language lateralization is unique to humans. Functional MRI (fMRI) and diffusion tensor imaging (DTI) enable the study of language areas and white matter fibers involved in language, respectively. The objective of this study was to correlate arcuate fasciculus (AF) laterality by diffusion tensor imaging with that by fMRI in preadolescent children which has not yet been reported. Ten children between 8 and 12 years were subjected to fMRI and DTI imaging using Siemens 1.5 T MRI. Two language fMRI paradigms - visual verb generation and word pair task - were used. Analysis was done using SPM8 software. In DTI, the fiber volume of the arcuate fasciculus (AFV) and fractional anisotropy (FA) was measured. The fMRI Laterality Index (fMRI-LI) and DTI Laterality Index (DTI-LI) were calculated and their correlation assessed using the Pearson Correlation Index. Of ten children, mean age 10.6 years, eight showed left lateralization while bilateral language lateralization was seen in two. AFV by DTI was more on the left side in seven of the eight children who had left lateralization by fMRI. DTI could not trace the AF in one child. Of the two with bilateral language lateralization on fMRI, one showed larger AFV on the right side while the other did not show any asymmetry. There was a significant correlation (p < 0.02) between fMRI-LI and DTI-LI. Group mean of AFV by DTI was higher on the left side (2659.89 ± 654.75 mm{sup 3}) as compared to the right (1824.11 ± 582.81 mm{sup 3}) (p < 0.01). Like fMRI, DTI also reveals language laterality in children with a high degree of correlation between the two imaging modalities. (orig.)

  5. Agouti-related peptide plays a critical role in leptin's effects on female puberty and reproduction

    OpenAIRE

    Sheffer-Babila, Sharone; Sun, Yan; Israel, Davelene D.; Liu, Shun-Mei; Neal-Perry, Genevieve; Streamson C Chua

    2013-01-01

    Deficient leptin signaling causes infertility via reduced activity of GnRH neurons, causing a hypogonadal state in both rodents and humans. Because GnRH neurons do not express leptin receptors, leptin's effect on GnRH neurons must be indirect. Neurons within the hypothalamic arcuate nucleus that coexpress AGRP and NPY are considered to be important intermediate neurons involved in leptin regulation of GnRH neurons. Previously, we reported that the absence of AGRP and haploinsufficiency of MC4...

  6. Pion degrees of freedom in nucleus-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Voskresenskii, D.N.; Senatorov, A.V.

    1988-07-01

    Within the framework of the theory of finite Fermi systems with the pion degree of freedom singled out explicitly we have discovered a number of qualitative effects which must be taken into account in calculations of the equation of state of heated dense nuclear matter. These effects are simulated in a calculation of the main characteristics of nucleus-nucleus collisions. The regularities found are in agreement with experimental indications, which confirms the idea of softness of the pion mode in dense heated nuclear matter.

  7. Dynamical nucleus-nucleus potential at short distances

    OpenAIRE

    Jiang, Yongying; Wang, Ning; Li, Zhuxia; Scheid, Werner

    2010-01-01

    The dynamical nucleus-nucleus potentials for fusion reactions 40Ca+40Ca, 48Ca+208Pb and 126Sn+130Te are studied with the improved quantum molecular dynamics (ImQMD) model together with the extended Thomas-Fermi approximation for the kinetic energies of nuclei. The obtained fusion barrier for 40Ca+40Ca is in good agreement with the extracted fusion barrier from the measured fusion excitation function, and the depth of the fusion pockets are close to the results of time-dependent Hartree-Fock c...

  8. Selected Experimental Highlights from Nucleus-Nucleus Collisions at RHIC

    CERN Document Server

    Huang, H Z

    2006-01-01

    Nucleus-nucleus collisions at RHIC produce high temperature and high energy density matter which exhibits partonic degrees of freedom. We will discuss measurements of nuclear modification factors for light hadrons and non-photonic electrons from heavy quark decays, which reflect the flavor dependence of energy loss of high momentum partons traversing the dense QCD medium. The hadronization of bulk partonic matter exhibits collectivity in effective partonic degrees of freedom. Nuclear collisions at RHIC provide an intriguing environment, where many constituent quark ingredients are readily available for possible formation of exotic particles through quark coalescences or recombinations.

  9. Caudal topographic nucleus isthmi and the rostral nontopographic nucleus isthmi in the turtle, Pseudemys scripta.

    Science.gov (United States)

    Sereno, M I; Ulinski, P S

    1987-07-15

    Isthmotectal projections in turtles were examined by making serial section reconstructions of axonal and dendritic arborizations that were anterogradely or retrogradely filled with HRP. Two prominent tectal-recipient isthmic nuclei--the caudal magnocellular nucleus isthmi (Imc) and the rostral magnocellular nucleus isthmi (Imr)--exhibited strikingly different patterns of organization. Imc cells have flattened, bipolar dendritic fields that cover a few percent of the area of the cell plate constituting the nucleus and they project topographically to the ipsilateral tectum without local axon branches. The topography was examined explicitly at the single-cell level by using cases with two injections at widely separated tectal loci. Each Imc axon terminates as a compact swarm of several thousand boutons placed mainly in the upper central gray and superficial gray layers. One Imc terminal spans less that 1% of the tectal surface. Imr cells, by contrast, have large, sparsely branched dendritic fields overlapped by local axon collaterals while distally, their axons nontopographically innervate not only the deeper layers of the ipsilateral tectum but also ipsilateral Imc. Imr receives a nontopographic tectal input that contrasts with the topographic tectal input to Imc. Previous work on nucleus isthmi emphasized the role of the contralateral isthmotectal projection (which originates from a third isthmic nucleus in turtles) in mediating binocular interactions in the tectum. The present results on the two different but overlapping ipsilateral tecto-isthmo-tectal circuits set up by Imc and Imr are discussed in the light of physiological evidence for selective attention effects and local-global interactions in the tectum.

  10. Compartmentalization of the precheliceral neuroectoderm in the spider Cupiennius salei: development of the arcuate body, optic ganglia, and mushroom body.

    Science.gov (United States)

    Doeffinger, Carola; Hartenstein, Volker; Stollewerk, Angelika

    2010-07-01

    Similarly to vertebrates, arthropod brains are compartmentalized into centers with specific neurological functions such as cognition, behavior, and memory. The centers can be further subdivided into smaller functional units. This raises the question of how these compartments are formed during development and how they are integrated into brain centers. We show here for the first time how the precheliceral neuroectoderm of the spider Cupiennius salei is compartmentalized to form the distinct brain centers of the visual system: the optic ganglia, the mushroom bodies, and the arcuate body. The areas of the visual brain centers are defined by the formation of grooves and vesicles and express the proneural gene CsASH1, followed by expression of the neural differentiation marker Prospero. Furthermore, the transcription factor dachshund, which is strongly enriched in the mushroom bodies and the outer optic ganglion of Drosophila, is expressed in the optic anlagen and the mushroom bodies of the spider. The developing brain centers are further subdivided into single neural precursor groups, which become incorporated into the grooves and vesicles but remain distinguishable throughout development, suggesting that they encode spatial information for neural subtype identity. Several molecular and morphological aspects of the development of the optic ganglia and the mushroom bodies are similar in the spider and in insects. Furthermore, we show that the primary engrailed head spot contributes neurons to the optic ganglia of the median eyes, whereas the secondary head spot, which has been associated with the optic ganglia in insects and crustaceans, is absent. PMID:20503430

  11. Lessons learned from a case of multivessel median arcuate ligament syndrome in the setting of an Arc of Buhler

    Directory of Open Access Journals (Sweden)

    Kevin O'Brien, M.D

    2016-09-01

    Full Text Available The median arcuate ligament (MAL can rarely compress both the celiac axis and superior mesenteric artery. We present a case of a 70-year male who presented with isolated episodes of upper abdominal pain and diarrhea associated with sweats and nausea. Angiography images demonstrated complete occlusion of the celiac axis and compression of the superior mesenteric artery during the expiration phases. The celiac axis was reconstituted distal to its origin by a patent Arc of Buhler. Other reported cases of multivessel MALs have produced severe symptoms in young adults requiring surgical and/or endovascular intervention. In this case, our patient's Arc of Buhler was protective against more severe chronic mesenteric ischemia. We suggest that a patent Arc of Buhler is protective against symptoms in a single vessel MALs patient. A significant percentage of patients receiving surgical intervention for MALs do not have relief of symptoms. There should be a search for an Arc of Buhler before surgical management of patients suspected to have single vessel MALs.

  12. Lessons learned from a case of multivessel median arcuate ligament syndrome in the setting of an Arc of Buhler.

    Science.gov (United States)

    O'Brien, Kevin; Ferral, Hector

    2016-09-01

    The median arcuate ligament (MAL) can rarely compress both the celiac axis and superior mesenteric artery. We present a case of a 70-year male who presented with isolated episodes of upper abdominal pain and diarrhea associated with sweats and nausea. Angiography images demonstrated complete occlusion of the celiac axis and compression of the superior mesenteric artery during the expiration phases. The celiac axis was reconstituted distal to its origin by a patent Arc of Buhler. Other reported cases of multivessel MALs have produced severe symptoms in young adults requiring surgical and/or endovascular intervention. In this case, our patient's Arc of Buhler was protective against more severe chronic mesenteric ischemia. We suggest that a patent Arc of Buhler is protective against symptoms in a single vessel MALs patient. A significant percentage of patients receiving surgical intervention for MALs do not have relief of symptoms. There should be a search for an Arc of Buhler before surgical management of patients suspected to have single vessel MALs. PMID:27594946

  13. Dopamine agonist-induced penile erection and yawning: differential role of D₂-like receptor subtypes and correlation with nitric oxide production in the paraventricular nucleus of the hypothalamus of male rats.

    Science.gov (United States)

    Sanna, Fabrizio; Succu, Salvatora; Melis, Maria Rosaria; Argiolas, Antonio

    2012-05-01

    The dopamine D₃ preferring agonist pramipexole (50 ng) induced penile erection and yawning when injected into the paraventricular nucleus of the hypothalamus of male rats, like the mixed D₁/D₂-like agonist apomorphine (50 ng), while the D₄ agonist PD 168,077 (100 ng), induced penile erection only. These responses lasted for 45-60 min and occurred with an increase of NO₂- and NO₃- concentrations in the dialysate obtained from the paraventricular nucleus by intracerebral microdialysis. Pramipexole and apomorphine responses were reduced by the D₂ preferring antagonist L-741,626 (5 μg), but not by the D₃ preferring antagonist SB-277011A (10 μg), or the D₄ preferring antagonist L-745,870 (5 μg), injected into the PVN before the dopamine agonist. In contrast, PD 168,077 responses were reduced by L-745,870, but not by L-741,626 or SB-277011A. Pramipexole, apomorphine and PD 168,077 effects were also reduced by the nitric oxide synthase inhibitor S-methyl-L-thiocitrulline (20 μg) and the N-type voltage-dependent Ca²⁺ channels blocker ω-conotoxin (5 ng), given into the paraventricular nucleus, and by the oxytocin antagonist d(CH₂)₅Tyr(Me)²-Orn⁸-vasotocin (2 μg), given intracerebroventricularly but not into the paraventricular nucleus before dopamine agonists. These results suggest that stimulation of D₂, but not D₃ or D₄ receptors, by pramipexole or apomorphine increases Ca²⁺ influx in cell bodies of oxytocinergic neurons. This increases the production of nitric oxide, which activates oxytocinergic neurotransmission in extra-hypothalamic brain areas and spinal cord, leading to penile erection and yawning. However, the stimulation of D₄ receptors by PD 168,077 also increases Ca²⁺ influx/nitric oxide production leading to penile erection, but not yawning. PMID:22391116

  14. Heavy-ion nucleus scattering

    CERN Document Server

    Rahman, M A; Haque, S

    2003-01-01

    Heavy ion-nucleus scattering is an excellent laboratory to probe high spin phenomena, exotic nuclei and for the analysis of various exit channels. The Strong Absorption Model or the generalized diffraction models, which are semi-classical in nature, have been employed in the description of various heavy ion-nucleus scattering phenomena with reasonable success. But one needs to treat the deflection function (scattering angles) quantum mechanically in the Wave Mechanical picture for the appropriate description of the heavy-ion nucleus scattering phenomena. We have brought the mathematics for the cross-section of the heavy-ion nucleus scattering to an analytic expression taking account of the deflection function (scattering angles) quantum mechanically. sup 9 Be, sup 1 sup 6 O, sup 2 sup 0 Ne and sup 3 sup 2 S heavy-ion beams elastic scattering from sup 2 sup 8 Si, sup 2 sup 4 Mg and sup 4 sup 0 Ca target nuclei at various projectile energies over the range 20-151 MeV have been analysed in terms of the 2-paramet...

  15. Nucleus accumbens dopamine receptors in the consolidation of spatial memory.

    NARCIS (Netherlands)

    Mele, A.; Avena, M.; Roullet, P.; Leonibus, E. de; Mandillo, S.; Sargolini, F.; Coccurello, R.; Oliverio, A.

    2004-01-01

    Nucleus accumbens dopamine is known to play an important role in motor activity and in behaviours governed by drugs and natural reinforcers, as well as in non-associative forms of learning. At the same time, activation of D1 and D2 dopamine receptors has been suggested to promote intracellular event

  16. Evidence for a periaqueductal gray-nucleus retroambiguus spinal cord pathway in the rat

    NARCIS (Netherlands)

    Holstege, G.; Kerstens, Lenka; Moes, M.C.; Horst, V.G.J.M. van der

    1997-01-01

    The nucleus retroambiguus in the cat has been shown to receive strong projections from the periaqueductal gray and to send fibres to distinct motoneuronal cell groups in brainstem and spinal cord. The nucleus retroambiguus plays a role in the production of vocalization and possibly copulatory (lordo

  17. Transverse Energy in nucleus-nucleus collisions: A review

    Energy Technology Data Exchange (ETDEWEB)

    Tincknell, M.

    1988-11-15

    The status of Transverse Energy (E/sub T/) in relativistic nucleus-nucleus collisions at the Brookhaven AGS and the CERN SPS is reviewed. The definition of E/sub T/ and its physical significance are discussed. The basic techniques and limitations of the experimental measurements are presented. The acceptances of the major experiments to be discussed are shown, along with remarks about their idiosyncrasies. The data demonstrate that the nuclear geometry of colliding spheres primarily determines the shapes of the observed spectra. Careful account of the acceptances is crucial to comparing and interpreting results. It is concluded that nuclear stopping power is high, and that the amount of energy deposited into the interaction volume is increasing with beam energy even at SPS energies. The energy densities believed to be obtained at the SPS are close to the critical values predicted for the onset of a quark-gluon plasma. 25 refs., 8 figs.

  18. Azimuthal correlation and collective behavior in nucleus-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Mali, P.; Mukhopadhyay, A., E-mail: amitabha-62@rediffmail.com; Sarkar, S. [University of North Bengal, Department of Physics (India); Singh, G. [SUNY at Fredonia, Department of Computer and Information Science (United States)

    2015-03-15

    Various flow effects of nuclear and hadronic origin are investigated in nucleus-nucleus collisions. Nuclear emulsion data collected from {sup 84}Kr + Ag/Br interaction at an incident energy of 1.52 GeV per nucleon and from {sup 28}Si + Ag/Br interaction at an incident energy of 14.5 GeV per nucleon are used in the investigation. The transverse momentum distribution and the flow angle analysis show that collective behavior, like a bounce-off effect of the projectile spectators and a sidesplash effect of the target spectators, are present in our event samples. From an azimuthal angle analysis of the data we also see a direct flow of the projectile fragments and of the produced charged particles. On the other hand, for both data samples the target fragments exhibit a reverse flow, while the projectile fragments exhibit an elliptic flow. Relevant flow parameters are measured.

  19. Azimuthal correlation and collective behavior in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Various flow effects of nuclear and hadronic origin are investigated in nucleus-nucleus collisions. Nuclear emulsion data collected from 84Kr + Ag/Br interaction at an incident energy of 1.52 GeV per nucleon and from 28Si + Ag/Br interaction at an incident energy of 14.5 GeV per nucleon are used in the investigation. The transverse momentum distribution and the flow angle analysis show that collective behavior, like a bounce-off effect of the projectile spectators and a sidesplash effect of the target spectators, are present in our event samples. From an azimuthal angle analysis of the data we also see a direct flow of the projectile fragments and of the produced charged particles. On the other hand, for both data samples the target fragments exhibit a reverse flow, while the projectile fragments exhibit an elliptic flow. Relevant flow parameters are measured

  20. Spectra Statistics for the Odd-Odd Nucleus 86Nb

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ren-Rong; ZHU Shun-Quan; CHENG Nan-Pu

    2001-01-01

    The energy levels of the odd-odd nucleus 86 Nb at low spins are calculated by using quasi-particles plus a rotor model. The distribution of the nearest-neighbour spacing and the spectral rigidity are studied. We find that the chaotic degree of the energy spectra increases with the increasing spin and reaches a maximum at I = 10; then it decreases gradually for spins above I = 10. The recoil term in the model Haniltonian makes the energy spectra slightly regular. The Coriolis force, however, makes the spectra chaotic and plays a major role in the spectral statistics of the odd-odd nucleus 86Nb.

  1. Final State Interactions Effects in Neutrino-Nucleus Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Golan, Tomasz [Univ. of Wroctaw (Poland); Juszczak, Cezary [Univ. of Wroctaw (Poland); Sobczyk, Jan T. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2012-07-01

    Final State Interactions effects are discussed in the context of Monte Carlo simulations of neutrino-nucleus interactions. A role of Formation Time is explained and several models describing this effect are compared. Various observables which are sensitive to FSI effects are reviewed including pion-nucleus interaction and hadron yields in backward hemisphere. NuWro Monte Carlo neutrino event generator is described and its ability to understand neutral current $\\pi^0$ production data in $\\sim 1$ GeV neutrino flux experiments is demonstrated.

  2. Formation and decay of a hot compound nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, B.V.; Dalmolin, F.T.; Dutra, M.; Santos, T.J., E-mail: brett@ita.br [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos SP (Brazil); Souza, S.R. [Universidade Federal de Rio Grande do Sul (UFRS), Porto Alegre RS, (Brazil); Universidade Federal de Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Fisica; Donangelo, R. [Instituto de Fisica, Universidad de la Republica de Uruguay, Montevideo (Uruguay); Universidade Federal de Rio Grande do Sul (UFRS), Porto Alegre RS, (Brazil)

    2014-07-01

    The compound nucleus plays an important role in nuclear reactions over a wide range of projectile-target combinations and energies. The limits that angular momentum places on its formation and existence are, for the most part, well understood. The limits on its excitation energy are not as clear. Here we first analyze general geometrical and thermodynamical features of a hot compound nucleus. We then discuss the manners by which it can decay and close by speculating on the high energy limit to its formation and existence. (author)

  3. Red nucleus and rubrospinal tract disorganization in the absence of Pou4f1

    Directory of Open Access Journals (Sweden)

    Jesus E. eMartinez-Lopez

    2015-02-01

    Full Text Available The red nucleus is a neuronal population that plays an important role in forelimb motor control and locomotion. Histologically it is subdivided into two subpopulations, the parvocellular red nucleus located in the diencephalon and the magnocellular red nucleus in the mesencephalon. The red nucleus integrates signals from motor cortex and cerebellum and projects to spinal cord interneurons and motor neurons through the rubrospinal tract. Pou4f1 is a transcription factor highly expressed in this nucleus that has been related to its specification. Here we profoundly analyzed consequences of Pou4f1 loss-of-function in development, maturation and axonal projection of the red nucleus. Surprisingly, red nucleus neurons are specified and maintained in the mutant, no cell death was detected. Nevertheless, the nucleus appeared disorganized with a strong delay in radial migration and with a wider neuronal distribution; the neurons did not form a compacted population as they do in controls, Robo1 and Slit2 were miss-expressed. Cplx1 and Npas1, expressed in the red nucleus, are transcription factors involved in neurotransmitter release, neuronal maturation and motor function processes among others. In our mutant mice, both transcription factors are lost, suggesting an abnormal maturation of the red nucleus. The resulting altered nucleus occupied a wider territory. Finally, we examined rubrospinal tract development and found that the red nucleus neurons were able to project to the spinal cord but their axons appeared defasciculated. These data suggest that Pou4f1 is necessary for the maturation of red nucleus neurons but not for their specification and maintenance.

  4. Kaonic nuclei and kaon-nucleus interactions

    CERN Document Server

    Ikuta, K; Masutani, K

    2002-01-01

    Although kaonic atoms provide valuable information concerning the K sup - -nucleus interaction at low energies, they cannot fully determine the K sup - - nucleus optical potential. We demonstrate that K sup - nuclear bound states, if they exist, can be useful in investigating the K sup - -nucleus interaction, especially in the interior of the nucleus. In order to show this possibility, we calculate the double differential cross sections for (K sup - , P) using the Green function method. (author)

  5. Extreme alpha-clustering in the 18O nucleus

    CERN Document Server

    Johnson, E D; Goldberg, V Z; Brown, S; Robson, D; Crisp, A M; Cottle, P D; Fu, C; Giles, J; Green, B W; Kemper, K W; Lee, K; Roeder, B T; Tribble, R E

    2009-01-01

    The structure of the 18O nucleus at excitation energies above the alpha decay threshold was studied using 14C+alpha resonance elastic scattering. A number of states with large alpha reduced widths have been observed, indicating that the alpha-cluster degree of freedom plays an important role in this N not equal Z nucleus. However, the alpha-cluster structure of this nucleus is very different from the relatively simple pattern of strong alpha-cluster quasi-rotational bands in the neighboring 16O and 20Ne nuclei. A 0+ state with an alpha reduced width exceeding the single particle limit was identified at an excitation energy of 9.9+/-0.3 MeV. We discuss evidence that states of this kind are common in light nuclei and give possible explanations of this feature.

  6. Formation of proton-fragments in hadron-nucleus and nucleus-nucleus collisions at high energies

    International Nuclear Information System (INIS)

    Full text: The investigation of production of protons in hadron- and nucleus-nucleus interactions is a key problem allowing one to establish the singularities of dynamics of nuclear interactions. The formation of proton-fragments at high energies of colliding particles proceeds within both the interaction of hadrons with nuclei and in the process of decay of the nucleus or its de-excitation at peripheral interactions. At different stages of interaction of impinging particle with target nucleus, the different mechanisms of formation of proton-fragments: the direct knock-out of intranuclear nucleons in the process of high energy cascade of an initial hadron, intranuclear cascade of produced particles, decay of the excited multi-nucleon fragments and of the thermalized remnant nucleus, and the coalescence of nuclear fragments to the new clusters are realized with the certain probability, connected to the interaction parameters (the interaction energy, the parameter of collision, the intranuclear density, the configuration of Fermi momentum of nucleons and clusters of target nucleus et al.). In its turn, the mechanisms of formation of the final nuclear fragments are closely related to the type of excitation of an initial nucleus. The peripheral interactions proceed at small transfers of the momentum of an impinging particle and represent the wide class of reactions covering the processes from diffractive or coulomb collective excitations of the whole nucleus to the direct quasi-elastic knock-out of the separate nucleons. Non-peripheral interactions are caused by comparatively high local transfers of momentum to the intranuclear clusters allowing the development of intranuclear cascade and the asymmetric redistribution of energy of an impinging particle. The central collisions causing the full decay of nucleus on nucleons or few-nucleon fragments, are the limiting case of the maximal development of the intranuclear cascade. The interaction of the initial particles with

  7. Atom as a "Dressed" Nucleus

    CERN Document Server

    Kalitvianski, V

    2008-01-01

    It is shown that electrostatic potential of atomic nucleus seen by a fast charged projectile at short distances is quite smeared due to nucleus motion around the atomic center of inertia. For example, the size of positive charge cloud in the Hydrogen ground state is much larger than the proper proton size. It is even bigger for the target atom in an excited state. Therefore the elastic scattering at large angles is generally weaker than the Rutherford one. In other words, the resulting elastic interaction with an atom at short distances is softer than the Colombian one due to a natural cutoff. In addition, the large angle scattering leads to the target atom excitations due to hitting the nucleus (inelastic processes). It is also shown that the Rutherford cross section is in fact the inclusive rather than the elastic one. These results are analogous to the QED ones. The difference and the value of the presented below non relativistic atomic calculations is in non perturbatively (exact) dressing that immediatel...

  8. Delta-nucleus dynamics: proceedings of symposium

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P. (eds.)

    1983-10-01

    The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta ..delta..(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe ..delta..-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented. (WHK)

  9. Delta-nucleus dynamics: proceedings of symposium

    International Nuclear Information System (INIS)

    The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta Δ(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe Δ-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented

  10. Behavioral Flexibility Is Increased by Optogenetic Inhibition of Neurons in the Nucleus Accumbens Shell during Specific Time Segments

    Science.gov (United States)

    Aquili, Luca; Liu, Andrew W.; Shindou, Mayumi; Shindou, Tomomi; Wickens, Jeffery R.

    2014-01-01

    Behavioral flexibility is vital for survival in an environment of changing contingencies. The nucleus accumbens may play an important role in behavioral flexibility, representing learned stimulus-reward associations in neural activity during response selection and learning from results. To investigate the role of nucleus accumbens neural activity…

  11. Pion production at 1800 in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    A survey experiment of pion production at 1800 in nucleus-nucleus collisions is presented. Beams of 1.05 GeV/A and 2.1 GeV/A protons, alphas, and carbon were used, as well as proton beams of 0.80 GeV, 3.5 GeV, and 4.89 GeV, and argon beams of 1.05 GeV/A and 1.83 GeV/A. This is the first such experiment to use the heavier beams. Targets used ranged from carbon to lead. An in-depth review of the literature, both experimental and theoretical, is also presented. The systematics of the data are discussed, and comparisons are made both with prior experiments and with the predictions of the models reviewed. The cross sections appear consistent with a simple single nucleon-nucleon collision picture, without the need for collective or other exotic effects. Suggestions for future work are made

  12. Applying the elastic model for various nucleus-nucleus fusion

    International Nuclear Information System (INIS)

    The Elastic Model of two free parameters m,d given by Scalia has been used for wider energy regions to fit the available experimental data for potential barriers and cross sections. In order to generalize Scalia's formula in both sub- and above-barrier regions, we calculated m, d for pairs rather than those given by Scalia and compared the calculated cross sections with the experimental data. This makes a generalization of the Elastic Model in describing fusion process. On the other hand, Scalia's range of interacting systems was 24 ≤ A ≤194 where A is the compound nucleus mass number. Our extension of that model includes an example of the pairs of A larger than his final limit aiming to make it as a general formula for any type of reactants: light, intermediate or heavy systems. A significant point is the comparison of Elastic Model calculations with the well known methods studying complete fusion and compound nucleus formation, namely with the resultants of using Proximity potential with either Sharp or Smooth cut-off approximations

  13. Genesis of Daba arcuate structural belt related to adjacent basement upheavals:Constraints from Fission-track and (U-Th)/He thermochronology

    Institute of Scientific and Technical Information of China (English)

    GUILLOT; Franois

    2010-01-01

    Fission-track, (U-Th)/He thermochronology, and cooling properties indicate that the southern Daba arcuate zone (SDBAZ) underwent a distinctive phase of rapid cooling in 153-100 Ma at a rate of 1.44-1.90°C/Ma. This rapid uplifting strongly contrasts with (1) the previous, rapid foreland subsidence during Early to Middle Jurassic in response to late-orogenic compression from the Qinling belt, (2) the succeeding long, slow cooling phase and relative thermal stability that occurred during the 100-45 Ma period. This rapid cooling event in the SDBAZ parallels those experienced by two adjacent upheavals of Huangling (HLUZ) and Hannan-Micang (HMUZ), with cooling rates of 2.22-3.17°C/Ma for the HLUZ in 160-126 Ma, 4.91°C/Ma for the southern HMUZ in 150-125 Ma, as well as 2.11°C/Ma for the northern HMUZ in 150-105 Ma. Comparing thermal histories among the SDBAZ, the HLUZ, the HMUZ, and the Wudang metamorphic zone (WDMZ), we infer that the Daba arcuate structural belt formed in 153-100 Ma. The combined dating data support a correlation with a low-angle arcuate south-thrusting of the Qinling orogen triggered by northward convergence of the Yangtze Craton, contemporaneously encountering rigid basement obstructions from the HLUZ and the HMUZ, respectively. Both the SDBAZ and neighboring domains additionally underwent a comparatively fast cooling and uplift since about 45 Ma.

  14. Brain networks modulated by subthalamic nucleus deep brain stimulation.

    Science.gov (United States)

    Accolla, Ettore A; Herrojo Ruiz, Maria; Horn, Andreas; Schneider, Gerd-Helge; Schmitz-Hübsch, Tanja; Draganski, Bogdan; Kühn, Andrea A

    2016-09-01

    Deep brain stimulation of the subthalamic nucleus is an established treatment for the motor symptoms of Parkinson's disease. Given the frequent occurrence of stimulation-induced affective and cognitive adverse effects, a better understanding about the role of the subthalamic nucleus in non-motor functions is needed. The main goal of this study is to characterize anatomical circuits modulated by subthalamic deep brain stimulation, and infer about the inner organization of the nucleus in terms of motor and non-motor areas. Given its small size and anatomical intersubject variability, functional organization of the subthalamic nucleus is difficult to investigate in vivo with current methods. Here, we used local field potential recordings obtained from 10 patients with Parkinson's disease to identify a subthalamic area with an analogous electrophysiological signature, namely a predominant beta oscillatory activity. The spatial accuracy was improved by identifying a single contact per macroelectrode for its vicinity to the electrophysiological source of the beta oscillation. We then conducted whole brain probabilistic tractography seeding from the previously identified contacts, and further described connectivity modifications along the macroelectrode's main axis. The designated subthalamic 'beta' area projected predominantly to motor and premotor cortical regions additional to connections to limbic and associative areas. More ventral subthalamic areas showed predominant connectivity to medial temporal regions including amygdala and hippocampus. We interpret our findings as evidence for the convergence of different functional circuits within subthalamic nucleus' portions deemed to be appropriate as deep brain stimulation target to treat motor symptoms in Parkinson's disease. Potential clinical implications of our study are illustrated by an index case where deep brain stimulation of estimated predominant non-motor subthalamic nucleus induced hypomanic behaviour.

  15. Resonances in -light nucleus systems

    Indian Academy of Sciences (India)

    K P Khemchandani; N G Kelkar; M Nowakowski; B K Jain

    2006-04-01

    We locate resonances in -light nucleus elastic scattering using the time delay method. We solve few-body equations within the finite rank approximation in order to calculate the -matrices and hence the time delay for the - 3He and - 4He systems. We find a resonance very close to the threshold in - 3 He elastic scattering, at about 0.5 MeV above threshold with a width of ∼ 2 MeV. The calculations also hint at the presence of sub-threshold states in both the cases.

  16. Turbulent mixing condensation nucleus counter

    Science.gov (United States)

    Mavliev, Rashid

    The construction and operating principles of the Turbulent Mixing Condensation Nucleus Counter (TM CNC) are described. Estimations based on the semiempirical theory of turbulent jets and the classical theory of nucleation and growth show the possibility of detecting particles as small as 2.5 nm without the interference of homogeneous nucleation. This conclusion was confirmed experimentally during the International Workshop on Intercomparison of Condensation Nuclei and Aerosol Particle Counters (Vienna, Austria). Number concentration, measured by the Turbulent Mixing CNC and other participating instruments, is found to be essentially equal.

  17. Nucleus Accumbens 1, a Pox virus and Zinc finger/Bric-a-brac Tramtrack Broad protein binds to TAR DNA-binding protein 43 and has a potential role in Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Scofield, M D; Korutla, L; Jackson, T G; Kalivas, P W; Mackler, S A

    2012-12-27

    Protein degradation is a critical component of cellular maintenance. The intracellular translocation and targeting of the Ubiquitin Proteasome System (UPS) differentially coordinates a protein's half-life and thereby its function. Nucleus Accumbens 1 (NAC1), a member of the Pox virus and Zinc finger/Bric-a-brac Tramtrack Broad complex (POZ/BTB) family of proteins, participates in the coordinated proteolysis of synaptic proteins by mediating recruitment of the UPS to dendritic spines. Here we report a novel interaction between NAC1 and TAR DNA-binding protein 43 (TDP-43), a protein identified as the primary component of ubiquitinated protein aggregates found in patients with Amyotrophic Lateral Sclerosis (ALS). In vitro translated full-length TDP-43 associated with both the POZ/BTB domain and the non-POZ/BTB domain of NAC1 in GST pulldown assays. Other POZ/BTB proteins (including zinc finger POZ/BTB proteins and atypical POZ/BTB proteins) showed weak interactions with TDP-43. In addition, NAC1 and TDP-43 were present in the same immunocomplexes in different regions of mouse brain and spinal cord. In primary spinal cord cultures, TDP-43 expression was mainly nuclear, whereas NAC1 was both nuclear and cytoplasmic. In order to mimic ALS-like toxicity in the spinal cord culture system, we elevated extracellular glutamate levels resulting in the selective loss of motor neurons. Using this model, it was found that glutamate toxicity elicited a dose-dependent translocation of TDP-43 out of the nucleus of cholinergic neurons and increased the co-localization of NAC1 and TDP-43. These findings suggest that NAC1 may function to link TDP-43 to the proteasome; thereby, facilitating the post-translational modifications of TDP-43 that lead to the development of ALS.

  18. New results on nuclear multifragmentation in nucleon-nucleus and nucleus-nucleus collisions at relativistic energies

    International Nuclear Information System (INIS)

    Some new aspects on the multifragmentation processes in nucleus-nucleus and nucleon-nucleus collisions at high energies are discussed in this work. Experimental data obtained in international collaborations (for example, MULTI Collaboration with KEK Tsukuba (Japan) and SKM 200 Collaboration with JINR Dubna (Russia)) are used to discuss new mechanisms in the target nucleus fragmentation. Correlations with stopping power, participant region size and energy density are included. Comparisons of the experimental results with the predictions of a phenomenological geometric model of intermediate mass fragment multiplicity, caloric curves and angular distributions are also presented. These results are used for global description of the multifragmentation processes in nucleon-nucleus and nucleus-nucleus collisions at relativistic energies. The size of the participant region and the average intermediate mass fragments multiplicity are taken into consideration using the free space probability. A few correlations between the deposited energy in the participant region and stability state of the intermediate mass fragments are presented in this work. The importance of the collision geometry in the multifragmentation processes is stressed. The results suggest different time moments for the incident nucleus fragmentation and for the target nucleus fragmentation. The associated entropies are distinct. (authors)

  19. Squish and squeeze-the nucleus as a physical barrier during migration in confined environments.

    Science.gov (United States)

    McGregor, Alexandra Lynn; Hsia, Chieh-Ren; Lammerding, Jan

    2016-06-01

    From embryonic development to cancer metastasis, cell migration plays a central role in health and disease. It is increasingly becoming apparent that cells migrating in three-dimensional (3-D) environments exhibit some striking differences compared with their well-established 2-D counterparts. One key finding is the significant role the nucleus plays during 3-D migration: when cells move in confined spaces, the cell body and nucleus must deform to squeeze through available spaces, and the deformability of the large and relatively rigid nucleus can become rate-limiting. In this review, we highlight recent findings regarding the role of nuclear mechanics in 3-D migration, including factors that govern nuclear deformability, and emerging mechanisms by which cells apply cytoskeletal forces to the nucleus to facilitate nuclear translocation. Intriguingly, the 'physical barrier' imposed by the nucleus also impacts cytoplasmic dynamics that affect cell migration and signaling, and changes in nuclear structure resulting from the mechanical forces acting on the nucleus during 3-D migration could further alter cellular function. These findings have broad relevance to the migration of both normal and cancerous cells inside living tissues, and motivate further research into the molecular details by which cells move their nuclei, as well as the consequences of the mechanical stress on the nucleus.

  20. Determination of Coil Inductances Cylindrical Iron Nucleus

    Directory of Open Access Journals (Sweden)

    Azeddine Mazouz

    2014-03-01

    Full Text Available The paper describes the investigation and development of a structure and performance characteristics of a coil iron nucleus cylindrical (C.I.N.C. The coil iron nucleus cylindrical is a nonlinear electro radio in which the moving of the nucleus in a sense or in other causes change in inductance and can reach extreme values at the superposition of nucleus and coil centers. The variation of the inductance and the degree of freedom of movement of the nucleus can lead to a device with electromechanical conversion The aim of this paper is the determination and visualization of self inductance and mutual of the (C.I.N.C based on geometric dimensions and the displacement of the nucleus.  

  1. An organism arises from every nucleus.

    OpenAIRE

    Nurullah Keklikoglu

    2009-01-01

    The fact that, cloning using somatic cell nuclear transfer (SCNT) method has been performed, opened new horizons for cloning, and changed the way of our understanding and approach to cell and nucleus. The progress in cloning technology, brought the anticipation of the ability to clone an organism from each somatic cell nucleus. Therefore, the 'Cell Theory' is about to take the additional statement as "An organism arises from every nucleus". The development of gene targeting procedures which c...

  2. Nucleus accumbens core lesions enhance two-way active avoidance

    OpenAIRE

    Lichtenberg, Nina T.; Kashtelyan, Vadim; Burton, Amanda C.; Bissonette, Gregory B.; Roesch, Matthew R.

    2013-01-01

    The majority of work examining nucleus accumbens core (NAc) has focused on functions pertaining to behaviors guided by appetitive outcomes. These studies have pointed to NAc as being critical for motivating behavior toward desirable outcomes. For example, we have recently shown that lesions of NAc impaired performance on a reward-guided decision-making task that required rats to choose between differently valued rewards. Unfortunately, much less is known about the role that NAc plays in motiv...

  3. Total cross sections for neutron-nucleus scattering

    OpenAIRE

    Suryanarayana, S. V.; H. Naik; Ganesan, S; Kailas, S; Choudhury, R. K.; Kim, Guinyum

    2010-01-01

    Systematics of neutron scattering cross sections on various materials for neutron energies up to several hundred MeV are important for ADSS applications. Ramsauer model is well known and widely applied to understand systematics of neutron nucleus total cross sections. In this work, we examined the role of nuclear effective radius parameter (r$_0$) on Ramsauer model fits of neutron total cross sections. We performed Ramsauer model global analysis of the experimental neutron total cross section...

  4. Integrated Azimuthal Correlations in Nucleus-Nucleus Collisions at CERN SPS

    OpenAIRE

    Grebieszkow, Katarzyna; Mrowczynski, Stanislaw

    2011-01-01

    Azimuthal correlations of particles produced in nucleus-nucleus collisions at CERN SPS are discussed. The correlations quantified by the integral measure Phi are shown to be dominated by effects of collective flow.

  5. Physical meaning of the yields from hadron-nucleon, hadron-nucleus, and nucleus-nucleus collisions observed in experiments

    International Nuclear Information System (INIS)

    A physical meaning of the outcomes from hadronic and nuclear collision processes at high energies is presented, as prompted experimentally. The fast and slow stages in hadron-nucleus collisions are distinguished. Hadrons are produced via intermediate objects observed in hadron-nucleus collisions. The intermediate objects may be treated as the groups of quarks or the quark bags. 37 refs

  6. Antibaryon-nucleus bound states

    CERN Document Server

    Hrtánková, J

    2014-01-01

    We calculated antibaryon ($\\bar{B}$ = $\\bar{p}$, $\\bar{\\Lambda}$, $\\bar{\\Sigma}$, $\\bar{\\Xi}$) bound states in selected nuclei within the relativistic mean-field (RMF) model. The G-parity motivated $\\bar{B}$-meson coupling constants were scaled to yield corresponding potentials consistent with available experimental data. Large polarization of the nuclear core caused by $\\bar{B}$ was confirmed. The $\\bar{p}$ annihilation in the nuclear medium was incorporated by including a phenomenological imaginary part of the optical potential. The calculations using a complex $\\bar{p}$-nucleus potential were performed fully self-consistently. The $\\bar{p}$ widths significantly decrease when the phase space reduction is considered for $\\bar{p}$ annihilation products, but they still remain sizeable for potentials consistent with $\\bar{p}$-atom data.

  7. 丘脑前核在三叉神经电刺激减轻癫痫发作和海马神经元损伤中的作用%Role of anterior thalamic nucleus in trigeminal nerve electrostimulation-induced reduction of seizures and hippocampal damage

    Institute of Scientific and Technical Information of China (English)

    王先红; 田苗苗; 潘晴晴; 鲁亚楠; 王玉

    2014-01-01

    [ ABSTRACT] AIM: To investigate the role of anterior thalamic nucleus in trigeminal nerve electrostimulation ( TNS)-induced effects on seizures and hippocampal damage.METHODS: The rats were intraperitoneally injected with pilocarpine to induce chronic epilepsy, and then received sham treatment, TNS treatment and TNS treatment after stereotac-tic lesion to the anterior thalamic nucleus.The TNS treatment lasted for 1 month in each group.Another injection of pilo-carpine was conducted to induce seizures, and the severity and duration of seizures were quantitatively evaluated.TUNEL, Fluoro-Jade B ( FJB) and Nissl staining were applied to determine in situ apoptosis, neuronal degeneration and neuron loss in the hippocampal CA1 area respectively.RESULTS:Compared with TNS group, TNS treatment after stereotactic lesion to the anterior thalamic nucleus significantly increased the severity and duration of seizures (P<0.05), and the numbers of TUNEL positive cells, FJB positive cells and lost neurons in the hippocampal CA1 area (P<0.01).CONCLUSION:Anterior thalamic nucleus plays a role in TNS-induced reduction of seizures and hippocampal damage.The mechanisms might be due to the chronically activation of the cortex through anterior thalamic nucleus pathway induced by TNS, resulting in the down-regulation of neuronal excitatory susceptibility.%目的:探讨丘脑前核在三叉神经电刺激( TNS)减轻癫痫发作和海马神经元损伤中的作用。方法:大鼠经腹腔注射匹罗卡品建立慢性癫痫模型,模型大鼠分别给予假刺激、三叉神经电刺激和立体定向毁损丘脑前核预处理后三叉神经电刺激1月,再次诱导癫痫发作,观察大鼠的癫痫行为表现,并通过TUNEL、Fluoro-Jade B ( FJB)染色和Nissl染色观察大鼠海马CA1区神经元的凋亡、变性及脱失情况。结果:与未经毁损丘脑前核的TNS处理大鼠相比,毁损丘脑前核后的TNS处理大鼠癫痫发作的级别分数

  8. Nucleus accumbens receives gastric vagal inputs

    Institute of Scientific and Technical Information of China (English)

    Sangeeta MEHENDALE; Jing-tian XIE; Han H AUNG; Xiong-Fei GUAN; Chun-Su YUAN

    2004-01-01

    AIM: To localize and characterize the response of single accumbal neurons to electrical stimulation of the gastric vagal fibers. METHODS: Unitary responses to electrical stimulation of the ventral and dorsal gastric vagal fibers which serve the proximal stomach were recorded extracellularly in the nucleus accumbens in anesthetized cats.RESULTS: The evoked units recorded in the nucleus accumbens consisted of phasic and tonic responses, with a mean latency of (396±43) ms. Convergence of ventral and dorsal gastric vagal inputs onto single phasic and tonic accumbal units was observed. For tonic inhibitory responses, convergence was exhibited when stimulation applied to both the ventral and dorsal gastric vagal branches resulted in a significantly longer inhibitory period than did stimulation of a single gastric vagal branch. Comparing the gastric vagally evoked accumbal unitary responses to the neuronal responses recorded in the nucleus tractus solitarius, parabrachial nucleus and hypothalamus in our previous studies, our data showed a higher percentage of single spike responses and shorter response duration's in the nucleus accumbens than in the other nuclei. This suggests that the synaptic drive from the gastric vagal inputs to the nucleus accumbens is less powerful than in the other structures. CONCLUSION: The present study localized and characterized gastric vagally evoked responses in the nucleus accumbens, which suggest that the nucleus accumbens may process gastric signals concerned with the ingestive process.

  9. Study of compound nucleus formation via bremsstrahlung emission in proton $\\alpha$-particle scattering

    CERN Document Server

    Maydanyuk, Sergei P

    2016-01-01

    In this paper a role of many-nucleon dynamics in formation of the compound $^{5}{\\rm Li}$ nucleus in the scattering of protons off $\\alpha$-particles at the proton incident energies up to 20 MeV is investigated. We propose a bremsstrahlung model allowing to extract information about probabilities of formation of such nucleus on the basis of analysis of experimental cross-sections of the bremsstrahlung photons. In order to realize this approach, the model includes elements of microscopic theory and also probabilities of formation of the short-lived compound nucleus. Results of calculations of the bremsstrahlung spectra are in good agreement with the experimental cross-sections.

  10. Comparative effects of ibotenic acid- and quisqualic acid-induced lesions of the substantia innominata on attentional function in the rat: further implications for the role of the cholinergic neurons of the nucleus basalis in cognitive processes.

    Science.gov (United States)

    Robbins, T W; Everitt, B J; Marston, H M; Wilkinson, J; Jones, G H; Page, K J

    1989-12-01

    Two experiments examined the effects of excitotoxic lesions of the substantia innominata on cholinergic activity in the neocortex and on performance in a paradigm measuring selective attention in the rat. In Expt. 1, ibotenate-induced lesions produced approximately 30% reductions in cortical choline acetyltransferase (ChAT) activity, and damage to wide regions of the substantia innominata and ventral pallidum. The rats were impaired in their ability to localize brief visual targets in a serial reaction time task, as measured by reduced choice accuracy. This impairment was particularly evident at short stimulus durations, but the lesioned rats did not exhibit evidence of primary visual sensory dysfunction and exhibited only minor deficits when the stimuli were presented unpredictably. The deficit was exacerbated when distracting white noise was interpolated into the task. The rats with lesions were also slower to respond correctly, probably resulting partly from the adoption of a speed/error trade-off strategy, and were slower to collect earned food pellets, although they made no more errors of omission than controls. In Expt. 2, quisqualate-induced lesions produced fewer signs of non-specific damage and 50% reductions in cortical ChAT activity. This lesion produced generally qualitatively similar, but weaker effects to those of ibotenate-induced lesions. It was notable that many of the deficits following either ibotenate- or quisqualate-induced lesions lasted for several months after surgery. The results are discussed in terms of the cholinergic hypothesis of cognitive dysfunction. It is argued that lesions of the substantia innominata, including the magnocellular cholinergic neurons of the nucleus basalis of Meynert, produce deficits in attentional processing, which may not result from damage specifically to cholinergic cells. However, the longevity of the effects makes these preparations suitable for further exploration of the restorative effects of cholinergic

  11. Structures and functions in the crowded nucleus: new biophysical insights

    Directory of Open Access Journals (Sweden)

    Ronald eHancock

    2014-09-01

    Full Text Available Concepts and methods from the physical sciences have catalysed remarkable progress in understanding the cell nucleus in recent years. To share this excitement with physicists and encourage their interest in this field, this review offers an overview of how the physics which underlies structures and functions in the nucleus is becoming more clear thanks to methods which have been developed to simulate and study macromolecules, polymers, and colloids. The environment in the nucleus is very crowded with macromolecules, making entropic (depletion forces major determinants of interactions. Simulation and experiments are consistent with their key role in forming membraneless compartments such as nucleoli, PML and Cajal bodies, and discrete territories for chromosomes. The chromosomes, giant linear polyelectrolyte polymers, exist in vivo in a state like a polymer melt. Looped conformations are predicted in crowded conditions, and have been confirmed experimentally and are central to the regulation of gene expression. Polymer theory has revealed how the chromosomes are so highly compacted in the nucleus, forming a crumpled globule with fractal properties which avoids knots and entanglements in DNA while allowing facile accessibility for its replication and transcription. Entropic repulsion between looped polymers can explain the confinement of each chromosome to a discrete region of the nucleus. Crowding and looping are predicted to facilitate finding the specific targets of factors which modulate activities of DNA. Simulation shows that entropic effects contribute to finding and repairing potentially lethal double-strand breaks in DNA by increasing the mobility of the broken ends, favouring their juxtaposition for repair. Signaling pathways are strongly influenced by crowding, which favours a processive mode of response (consecutive reactions without releasing substrates. This new information contributes to understanding the sometimes counter

  12. Angular characteristics of pion-nucleus interaction

    International Nuclear Information System (INIS)

    In the present paper pion-nucleus interactions have been studied using nuclear emulsion technique. The investigation of these interactions is expected to provide some very useful information about the multiparticle production mechanism. Nuclear emulsion is a material which memorizes the tracks of charged particles. When a primary particle collides with a nucleus, it may interact with the nucleons of the target nucleus in two ways. In the first case, independent reactions may take place between the incident particle and the nucleons present in the target nucleus. Secondly the primary particle may interact coherently with the various nucleons of the target nucleus and the secondary particles are produced. Angular distribution of charged secondaries produced in these interactions has been studied for central collision events. Different workers have used different criterion for the selection of central collisions. We analysed the events with high shower particle multiplicity i.e., Ns ≥ 28 and call them as central collision events

  13. Somatostatin receptors in the nucleus accumbens modulate dopamine-dependent but not acetylcholine-dependent turning behaviour of rats.

    NARCIS (Netherlands)

    Ikeda, H.; Kotani, A.; Koshikawa, N.; Cools, A.R.

    2009-01-01

    The role of somatostatin receptors in the nucleus accumbens shell in rat turning behaviour was studied. Unilateral injection of neither the somatostatin receptor agonist somatostatin (1.0 microg) nor the somatostatin receptor antagonist cyclosomatostatin (100.0 ng) into the nucleus accumbens shell e

  14. 5-Hydroxytryptamine 2C receptors tonically augment synaptic currents in the nucleus tractus solitarii

    OpenAIRE

    Austgen, James R.; Dantzler, Heather A.; Barger, Brenna K.; Kline, David D.

    2012-01-01

    The nucleus tractus solitarii (nTS) is the primary termination and integration point for visceral afferents in the brain stem. Afferent glutamate release and its efficacy on postsynaptic activity within this nucleus are modulated by additional neuromodulators and transmitters, including serotonin (5-HT) acting through its receptors. The 5-HT2 receptors in the medulla modulate the cardiorespiratory system and autonomic reflexes, but the distribution of the 5-HT2C receptor and the role of these...

  15. Glucagon-Like Peptide 1 Receptors in Nucleus Accumbens Affect Food Intake

    OpenAIRE

    Dossat, Amanda M.; Lilly, Nicole; Kay, Kristen; Williams, Diana L.

    2011-01-01

    Central glucagon-like peptide 1 receptor (GLP-1R) stimulation suppresses food intake, and hindbrain GLP-1 neurons project to numerous feeding-relevant brain regions. One such region is the nucleus accumbens (NAc), which plays a role in reward and motivated behavior. Using immunohistochemical and retrograde tracing techniques in rats, we identified a robust projection from GLP-1 neurons in the nucleus of the solitary tract to the NAc. We hypothesized that activation of NAc GLP-1Rs suppresses f...

  16. Nuclear organization in the 3D space of the nucleus – cause or consequence?

    OpenAIRE

    Nunez, Esperanza; Fu, Xiang-Dong; Rosenfeld, Michael G.

    2009-01-01

    Recent evidence suggests that dynamic three-dimensional genomic interactions in the nucleus exert critical roles in regulated gene expression. Here, we review a series of recent paradigm-shifting experiments that highlight the existence of specific gene networks within the self-organizing space of the nucleus. These gene networks, evidenced by long-range intra- and inter-chromosomal interactions, can be considered as the cause or consequence of regulatory biological programs. Changes in nucle...

  17. Role of nitric oxide of the median preoptic nucleus (MnPO in the alterations of salivary flow, arterial pressure and heart rate induced by injection of pilocarpine into the MnPO and intraperitoneally

    Directory of Open Access Journals (Sweden)

    Wilson A. Saad

    2003-07-01

    Full Text Available We investigated the effect of L-NAME, a nitric oxide (NO inhibitor and sodium nitroprusside (SNP, an NO-donating agent, on pilocarpine-induced alterations in salivary flow, mean arterial blood pressure (MAP and heart rate (HR in rats. Male Holtzman rats (250-300 g were implanted with a stainless steel cannula directly into the median preoptic nucleus (MnPO. Pilocarpine (10, 20, 40, 80, 160 µg injected into the MnPO induced an increase in salivary secretion (P<0.01. Pilocarpine (1, 2, 4, 8, 16 mg/kg ip also increased salivary secretion (P<0.01. Injection of L-NAME (40 µg into the MnPO prior to pilocarpine (10, 20, 40, 80, 160 µg injected into the MnPO or ip (1, 2, 4, 8, 16 mg/kg increased salivary secretion (P<0.01. SNP (30 µg injected into the MnPO or ip prior to pilocarpine attenuated salivary secretion (P<0.01. Pilocarpine (40 µg injection into the MnPO increased MAP and decreased HR (P<0.01. Pilocarpine (4 mg/kg body weight ip produced a decrease in MAP and an increase in HR (P<0.01. Injection of L-NAME (40 µg into the MnPO prior to pilocarpine potentiated the increase in MAP and reduced HR (P<0.01. SNP (30 µg injected into the MnPO prior to pilocarpine attenuated (100% the effect of pilocarpine on MAP, with no effect on HR. Administration of L-NAME (40 µg into the MnPO potentiated the effect of pilocarpine injected ip. SNP (30 µg injected into the MnPO attenuated the effect of ip pilocarpine on MAP and HR. The present study suggests that in the rat MnPO 1 NO is important for the effects of pilocarpine on salivary flow, and 2 pilocarpine interferes with blood pressure and HR (side effects of pilocarpine, that is attenuated by NO.

  18. Whole-brain mapping of afferent projections to the bed nucleus of the stria terminalis in tree shrews.

    Science.gov (United States)

    Ni, Rong-Jun; Luo, Peng-Hao; Shu, Yu-Mian; Chen, Ju-Tao; Zhou, Jiang-Ning

    2016-10-01

    The bed nucleus of the stria terminalis (BST) plays an important role in integrating and relaying input information to other brain regions in response to stress. The cytoarchitecture of the BST in tree shrews (Tupaia belangeri chinensis) has been comprehensively described in our previous publications. However, the inputs to the BST have not been described in previous reports. The aim of the present study was to investigate the sources of afferent projections to the BST throughout the brain of tree shrews using the retrograde tracer Fluoro-Gold (FG). The present results provide the first detailed whole-brain mapping of BST-projecting neurons in the tree shrew brain. The BST was densely innervated by the prefrontal cortex, entorhinal cortex, ventral subiculum, amygdala, ventral tegmental area, and parabrachial nucleus. Moreover, moderate projections to the BST originated from the medial preoptic area, supramammillary nucleus, paraventricular thalamic nucleus, pedunculopontine tegmental nucleus, dorsal raphe nucleus, locus coeruleus, and nucleus of the solitary tract. Afferent projections to the BST are identified in the ventral pallidum, nucleus of the diagonal band, ventral posteromedial thalamic nucleus, posterior complex of the thalamus, interfascicular nucleus, retrorubral field, rhabdoid nucleus, intermediate reticular nucleus, and parvicellular reticular nucleus. In addition, the different densities of BST-projecting neurons in various regions were analyzed in the tree shrew brains. In summary, whole-brain mapping of direct inputs to the BST is delineated in tree shrews. These brain circuits are implicated in the regulation of numerous physiological and behavioral processes including stress, reward, food intake, and arousal. PMID:27436534

  19. The retrotrapezoid nucleus and breathing.

    Science.gov (United States)

    Guyenet, Patrice G; Stornetta, Ruth L; Abbott, Stephen B G; Depuy, Seth D; Kanbar, Roy

    2012-01-01

    The retrotrapezoid nucleus (RTN) is located in the rostral medulla oblongata close to the ventral surface and consists of a bilateral cluster of glutamatergic neurons that are non-aminergic and express homeodomain transcription factor Phox2b throughout life. These neurons respond vigorously to increases in local pCO(2) via cell-autonomous and paracrine (glial) mechanisms and receive additional chemosensory information from the carotid bodies. RTN neurons exclusively innervate the regions of the brainstem that contain the respiratory pattern generator (RPG). Lesion or inhibition of RTN neurons largely attenuates the respiratory chemoreflex of adult rats whereas their activation increases respiratory rate, inspiratory amplitude and active expiration. Phox2b mutations that cause congenital central hypoventilation syndrome in humans prevent the development of RTN neurons in mice. Selective deletion of the RTN Phox2b-VGLUT2 neurons by genetic means in mice eliminates the respiratory chemoreflex in neonates.In short, RTN Phox2b-VGLUT2 neurons are a major nodal point of the CNS network that regulates pCO(2) via breathing and these cells are probable central chemoreceptors. PMID:23080151

  20. Analysis of Subthreshold Antiproton Production in p-Nucleus and Nucleus-Nucleus Collisions in the RBUU Approach

    CERN Document Server

    Teis, S; Maruyama, T; Mosel, U; Teis, Stefan; Cassing, Wolfgang; Maruyama, Tomoyuki; Mosel, Ulrich

    1994-01-01

    We calculate the subthreshold production of antiprotons in the Lorentz-covariant RBUU approach employing a weighted testparticle method to treat the antiproton propagation and absorption nonperturbatively. We find that the pbar differential cross sections are highly sensitive to the baryon and antiproton selfenergies in the dense baryonic environment. Adopting the baryon scalar and vector selfenergies from the empirical optical potential for proton-nucleus elastic scattering and from Dirac-Brueckner calculations at higher density rho > rho_0 we examine the differential pbar spectra as a function of the antiproton selfenergy. A detailed comparison with the available experimental data for p-nucleus and nucleus-nucleus reactions shows that the antiproton feels a moderately attractive mean-field at normal nuclear matter density rho_0 which is in line with a dispersive potential extracted from the free annihilation cross section.

  1. Nucleus accumbens stimulation in pathological obesity.

    Science.gov (United States)

    Harat, Marek; Rudaś, Marcin; Zieliński, Piotr; Birska, Julita; Sokal, Paweł

    2016-01-01

    One of the potential treatment methods of obesity is deep brain stimulation (DBS) of nucleus accumbens. We describe the case of 19 years old woman with hypothalamic obesity. She weighted 151.4 kg before DBS and the non-surgical methods proved to be inefficient. She was treated with implantation of DBS electrode to nucleus accumbens bilaterally. Results were measured with body mass index and neuropsychological tests. Follow-up was 14 months. Fourteen months after surgery weight was 138 kg, BMI was 48.3. Neuropsychological test results were intact. The presented case supports the thesis of treatment of obesity with nucleus accumbens stimulation. PMID:27154450

  2. Study of Hadron Production in Hadron-Nucleus and Nucleus-Nucleus Collisions at the CERN SPS

    CERN Multimedia

    Selyuzhenkov, I; Kowalski, S; Kaptur, E A; Kowalik, K L; Dominik, W M; Krasnoperov, A; Feofilov, G; Vinogradov, L; Kovalenko, V; Johnson, S R; Mills, G B; Planeta, R J; Rubbia, A; Robert, A L; Marton, K; Messerly, B A; Puzovic, J; Bogomilov, M V; Bravar, A; Sgalaberna, D; Renfordt, R A E; Deveaux, M; Engel, R R; Grzeszczuk, A; Davis, N; Kuich, M; Lyubushkin, V; Igolkin, S; Kondratev, V; Kadija, K; Diakonos, F; Slodkowski, M A; Rauch, W H; Pistillo, C; Laszlo, A; Nakadaira, T; Hasegawa, T; Zambelli, L A; Sadovskiy, A; Morozov, S; Petukhov, O; Szuba, M K; Mathes, H; Herve, A E; Roehrich, D; Marino, A D; Wyszynski, O J; Grebieszkow, K; Di luise, S; Wlodarczyk, Z; Rybczynski, M A; Wojtaszek-szwarc, A; Nirkko, M C; Sakashita, K; Golubeva, M; Kurepin, A; Manic, D; Kolev, D I; Kisiel, J E; Rondio, E; Czopowicz, T R; Seyboth, P; Turko, L; Guber, F; Marin, V; Busygina, O; Taranenko, A; Cirkovic, M; Gazdzicki, M; Roth, M A; Pulawski, S M; Aduszkiewicz, A M; Bunyatov, S; Vechernin, V; Nagai, Y; Anticic, T; Larsen, D T; Dynowski, K M; Mackowiak-pawlowska, M K; Stefanek, G; Pavin, M; Fodor, Z P; Nishikawa, K; Tada, M; Kobayashi, T; Blondel, A P P; Hasler, A; Damyanova, A; Stroebele, H W; Rustamov, A; Klochkov, V; Posiadala, M Z; Kolesnikov, V; Andronov, E; Zimmerman, E D; Antoniou, N; Majka, Z; Veberic, D; Dumarchez, J; Naskret, M; Ivashkin, A; Tsenov, R V; Koziel, M G; Schmidt, K J; Melkumov, G; Popov, B; Panagiotou, A; Richter-was, E M; Ereditato, A; Paolone, V; Korzenev, A; Unger, M T; Wilczek, A G; Stepaniak, J M; Matulewicz, T N; Seryakov, A; Susa, T; Staszel, P P; Marcinek, A J; Brzychczyk, J; Maksiak, B; Tefelski, D B

    2007-01-01

    The NA61/SHINE (SHINE = SPS Heavy Ion and Neutrino Experiment) experiment is a large acceptance hadron spectrometer at the CERN SPS for the study of the hadronic final states produced in interactions of various beam particles (pions, protons, C, S and In) with a variety of fixed targets at the SPS energies. The main components of the current detector were constructed and used by the NA49 experiment. The physics program of NA61/SHINE consists of three main subjects. In the first stage of data taking (2007-2009) measurements of hadron production in hadron-nucleus interactions needed for neutrino (T2K) and cosmic-ray (Pierre Auger and KASCADE) experiments will be performed. In the second stage (2009-2011) hadron production in proton-proton and proton-nucleus interactions needed as reference data for a better understanding of nucleus-nucleus reactions will be studied. In the third stage (2009-2013) energy dependence of hadron production properties will be measured in nucleus-nucleus collisions as well as in p+p a...

  3. Parabrachial nucleus involvement in multiple system atrophy☆

    OpenAIRE

    Benarroch, E.E.; Schmeichel, A.M.; Low, P. A.; Parisi, J.E.

    2013-01-01

    Multiple system atrophy (MSA) is associated with respiratory dysfunction, including sleep apnea, respiratory dysrhythmia, and laryngeal stridor. Neurons of the parabrachial nucleus (PBN) control respiratory rhythmogenesis and airway resistance.

  4. The nucleus in Finland - The second report

    International Nuclear Information System (INIS)

    The Finnish Nuclear Society (FNS) started the distribution of the Nucleus bulletin at the beginning of 1988. The volume of distribution has been extended since, including today nearly 1,000 persons. Both the English and the Finnish version of the bulletin is sent to various opinion leaders of society, i.e. the members of the parliament, ministries, the media, representatives of industry and other decision-makers of the energy field. After the five-year history of the Nucleus in Finland, it is time to look back and sum up the present status of the Nucleus. This report gives a short summary concerning the present distribution and its efficiency, the experiences gained and the influence of the bulletin in Finland. The first questionnaire was sent in November 1988, and the survey was repeated among the Finnish readers of the Nucleus in autumn 1992. The results of the latter survey are given in this report

  5. The role of kisspeptin and gonadotropin inhibitory hormone in the seasonal regulation of reproduction in sheep.

    Science.gov (United States)

    Smith, J T

    2012-08-01

    Sheep are seasonal breeders, experiencing an annual period of reproductive quiescence in response to increased photoperiod during the late-winter into spring and renaissance during the late summer. The nonbreeding (anestrous) season is characterized by a reduction in the pulsatile secretion of GnRH from the brain, in part because of an increase in negative feedback activity of estrogen. Neuronal populations in the hypothalamus that produce kisspeptin and gonadotropin-inhibitory hormone (GnIH) appear to be important for the seasonal shift in reproductive activity, and the former are also mandatory for puberty onset. Kisspeptin cells in the arcuate nucleus (ARC) and preoptic area appear to regulate GnRH neurons and transmit sex-steroid feedback signals to these neurons. Moreover, kisspeptin expression in the ARC is markedly up-regulated at the onset of the breeding season, as too are the number of kisspeptin fibers in close apposition to GnRH neurons. The lower levels of kisspeptin seen during the nonbreeding season can be "corrected" by infusion of kisspeptin, which causes ovulation in seasonally acyclic females. The role of GnIH is less clear, but mounting evidence supports a role for this neuropeptide in the inhibitory regulation of both GnRH secretion and gonadotropin release from the pituitary gland. Contrary to kisspeptin, GnIH expression is markedly reduced at the onset of the breeding season. In addition, the number of GnIH fibers in close apposition to GnRH neurons also decreases during this time. Importantly, exogenous GnIH treatment can block both the pulsatile release of LH and the preovulatory LH surge during the breeding season. In summary, it is most likely the integrated function of both these neuropeptide systems that modulate the annual shift in photoperiod to a physiological change in fertility.

  6. Testing string dynamics in lepton nucleus reactions

    International Nuclear Information System (INIS)

    The sensitivity of nuclear attenuation of 10-100 GeV lepton nucleus (ell A) reactions to space-time aspects of hadronization is investigated within the context of the Lund string model. We consider two mechanisms for attenuation in a nucleus: final state cascading and string flip excitations. Implications for the evolution of the energy density in nuclear collisions are discussed. 16 refs., 10 figs

  7. Towards Construction of a Unified Model for the Neutrino-Nucleus Reactions

    CERN Document Server

    Nakamura, S X; Hayato, Y; Hirai, M; Horiuchi, W; Kumano, S; Murata, T; Saito, K; Sakura, M; Sato, T; Suzuki, Y

    2016-01-01

    A precise description of neutrino-nucleus reactions will play a key role in addressing fundamental questions such as the leptonic CP violation and the neutrino mass hierarchy through analyzing data from next-generation neutrino oscillation experiments. The neutrino energy relevant to the neutrino-nucleus reactions spans a broad range and, accordingly, the dominant reaction mechanism varies across the energy region from quasi-elastic scattering through nucleon resonance excitations to deep inelastic scattering. This corresponds to transitions of the effective degree of freedom for theoretical description from nucleons through meson-baryon to quarks. The main purpose of this review is to report our recent efforts towards a unified description of the neutrino-nucleus reactions over the wide energy range; recent overall progress in the field is also sketched. Starting with an overview of the current status of neutrino-nucleus scattering experiments, we formulate the cross section to be commonly used for the react...

  8. Proton-Nucleus Collisions at the LHC: Scientific Opportunities and Requirements

    CERN Document Server

    Salgado, C A; Arleo, F; Armesto, N; Botje, M; Cacciari, M; Campbell, J; Carli, C; Cole, B; D'Enterria, D; Gelis, F; Guzey, V; Hencken, K; Jacobs, P; Jowett, J M; Klein, S R; Maltoni, F; Morsch, A; Piotrzkowski, K; Qiu, J W; Satogata, T; Sikler, F; Strikman, M; Takai, H; Vogt, R; Wessels, J P; White, S N; Wiedemann, U A; Wyslouch, B; Zhalov, M

    2012-01-01

    Proton-nucleus (p+A) collisions have long been recognized as a crucial component of the physics programme with nuclear beams at high energies, in particular for their reference role to interpret and understand nucleus-nucleus data as well as for their potential to elucidate the partonic structure of matter at low parton fractional momenta (small-x). Here, we summarize the main motivations that make a proton-nucleus run a decisive ingredient for a successful heavy-ion programme at the Large Hadron Collider (LHC) and we present unique scientific opportunities arising from these collisions. We also review the status of ongoing discussions about operation plans for the p+A mode at the LHC.

  9. 褪黑素对损毁弓状核大鼠所致肥胖的干预研究%Antiobesity effect of melatonin on SD rats induced by arcuate nucleus lesion

    Institute of Scientific and Technical Information of China (English)

    孙倩; 杨美子; 王东; 王桂华; 许勇

    2011-01-01

    Objective To investigate the affection of melatonin on obesity rats with monosodium glutamate (MSG).Methods The model of obesity rats were induced using subcutaneous injection of glutamic sodium for 5 days.The BMI, body temperature, food intake and fat weight in rats were determined and compared.The serum triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL) and pathological factors were also detected.Results Compared with the control group, the body weight and Lee's index of model group were significantly increased (P < 0.05 ), while the body length decreased.Compared with model group, the body weight of melatonin treatment group were back down (P <0.05, P<0.01).Compared with model group, the body temperature in low and high dose of melatonin group gradually increased and the blood pressure decreased.In the melatonin high and low dose group, the weight of white fat was significantly lower than the model group (P < 0.01, P < 0.05 ) while the brown fat was significantly increased (P <0.05, P <0.01 ).The level of TG, HDL and LDL in blood in low and high dose of melatonin groups decreased significantly (P < 0.05, P <0.01 ).Conclusion The study indicate that melatonin prevent the obesity in MSG -treated rats.Its maybe related to the up -regulation of energy metabolism by MLT.%目的 观察褪黑素对损毁弓状核大鼠所致肥胖的干预作用.方法 皮下注射谷氨酸钠,建立大鼠弓状核损毁所致中枢性肥胖,比较各组大鼠体质量指数(BMI) ;测定体温变化、摄食量和脂肪重;检测甘油三酯(TG)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)等和血压;观察弓状核病理学变化.结果 褪黑素处理肥胖大鼠后,体温逐渐升高,其中高、低剂量给药组大鼠的BMI均明显回降(P<0.05,P<0.01),血压降低(P<0.01,P<0.05).褪黑素高、低剂量组大鼠体内白色脂肪重量,较模型组明显降低(P<0.01,P<0.05),棕色脂肪量明显增多(P<0.05,P<0.01).甘油三酯、高密度脂蛋白和低密度脂蛋白含量,褪黑素治疗组明显降低(P<0.01).结论 褪黑素对损毁大鼠弓状核所致肥胖具有干预作用,可能是由于其使能量消耗增多对肥胖有一定的抵抗作用.

  10. Effect of hypothalamic arcuate nucleus damaged by monosodium glutamate on bone histomorphometry parameters in rat%损毁弓状核对大鼠骨组织形态计量学的影响

    Institute of Scientific and Technical Information of China (English)

    刘锡仪; 刘浩宇; 张巍

    2007-01-01

    目的:研究损毁下丘脑弓状核对大鼠骨组织形态计量学的影响.方法:SD大鼠于出生后第1、3、5、7、9 d皮下注射10%谷氨酸单钠(MSG)(4 g/kg BW),对照组同法注射等体积生理盐水,并设MSG毒性对照组,于70 d龄同法注射MSG,各组大鼠皆存活至160 d.用3%戊巴比妥钠腹腔麻醉,用4%多聚甲醛经左心室行全身灌注,取脑作下丘脑弓状核冠状面切片,HE染色.取右侧胫骨常规脱钙,石蜡包埋,矢状面连续切片,胶原特殊染色,用于显示骨小梁结构.HE染色用于破骨细胞计数.图像分析仪对弓状核正中隆起切面和骨组织进行照片和计量.用放免法测血清中GH(生长素)、E2(雌二醇)和T(睾酮)含量.结果:MSG大鼠弓状核神经细胞数量显著减少,GH和E2、T水平明显降低,骨量显著减少,发生骨质疏松,NS组和MSG毒性对照组弓状核、GH、E2、T和骨组织无明显改变.结论:①MSG大鼠骨组织的改变不是MSG对垂体和骨组织的毒性作用所致; ②下丘脑弓状核参与骨代谢的调控; ③通过GH和性激素作用是ARC参与骨代谢调控的重要途径.

  11. Multiplicity spectra in relativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    The gross features of the observed multiplicity data appear to be accounted for by simple geometrical considerations in combination with the assumption of uncorrelated nucleons. They provide no indication that coherent phenomena play a role. The systematics of the data with projectile and target mass draw attention to the fact that in a multiple collision picture saturation effects for the production of pions take place with the tendency that pions are produced proportionally to the number of nucleons involved in the reaction. (orig.)

  12. Active galactic nucleus feedback in clusters of galaxies.

    Science.gov (United States)

    Blanton, Elizabeth L; Clarke, T E; Sarazin, Craig L; Randall, Scott W; McNamara, Brian R

    2010-04-20

    Observations made during the last ten years with the Chandra X-ray Observatory have shed much light on the cooling gas in the centers of clusters of galaxies and the role of active galactic nucleus (AGN) heating. Cooling of the hot intracluster medium in cluster centers can feed the supermassive black holes found in the nuclei of the dominant cluster galaxies leading to AGN outbursts which can reheat the gas, suppressing cooling and large amounts of star formation. AGN heating can come in the form of shocks, buoyantly rising bubbles that have been inflated by radio lobes, and the dissipation of sound waves. PMID:20351250

  13. Hypersexuality following subthalamic nucleus stimulation for Parkinson′s disease

    Directory of Open Access Journals (Sweden)

    Doshi Paresh

    2008-01-01

    Full Text Available Subthalamic nucleus (STN stimulation is an established surgical treatment for Parkinson′s disease (PD. Though the motor benefits of STN stimulation are well understood, its cognitive and behavioral effects are still not fully understood. Manic psychosis, hypersexuality, pathological gambling and mood swings are associated with advanced PD. There have been reports to suggest improvement or worsening in these symptoms following STN deep brain stimulation (DBS. We report two cases as the sole behavioral side-effects of STN stimulation despite good clinical improvement on long-term follow-up. These patients and literature review suggests the complex role of STN stimulation in motor and behavioral control.

  14. Electric multipole response of the halo nucleus $^6$He

    CERN Document Server

    Singh, Jagjit; Vitturi, A; Chatterjee, R

    2016-01-01

    The role of different continuum components in the weakly-bound nucleus $^6$He is studied by coupling unbound spd-waves of $^5$He by means of simple pairing contact-delta interaction. The results of our previous investigations in a model space containing only p-waves, showed the collective nature of the ground state and allowed the calculation of the electric quadrupole transitions. We extend this simple model by including also sd-continuum neutron states and we investigate the electric monopole, dipole and octupole response of the system for transitions to the continuum, discussing the contribution of different configurations.

  15. Level density of radioactive doubly-magic nucleus 56Ni

    International Nuclear Information System (INIS)

    In this work the single particle energies are obtained by diagonalising the Nilsson Hamiltonian in the cylindrical basis and are generated up to N =11 shells for the isotopes of Ni from A = 48-70, emphasizing the three magic nuclei viz, 48Ni, 56Ni and 68Ni. The statistical quantities like excitation energy, level density parameter and nuclear level density which play the important roles in the nuclear structure and nuclear reactions can be calculated theoretically by means of the Statistical or Partition function method. Hence the statistical model approach is followed to probe the dynamical properties of the nucleus in the microscopic level

  16. Active galactic nucleus feedback in clusters of galaxies

    CERN Document Server

    Blanton, Elizabeth L; Sarazin, Craig L; Randall, Scott W; McNamara, Brian R; ),

    2010-01-01

    Observations made during the last ten years with the Chandra X-ray Observatory have shed much light on the cooling gas in the centers of clusters of galaxies and the role of active galactic nucleus (AGN) heating. Cooling of the hot intracluster medium in cluster centers can feed the supermassive black holes found in the nuclei of the dominant cluster galaxies leading to AGN outbursts which can reheat the gas, suppressing cooling and large amounts of star formation. AGN heating can come in the form of shocks, buoyantly rising bubbles that have been inflated by radio lobes, and the dissipation of sound waves.

  17. Nucleus-Nucleus Scattering Based on a Modified Glauber Theory

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yao-Lin; MA Zhong-Yu; CHEN Bao-Qiu

    2001-01-01

    A modified microscopic Glauber theory has been extended to investigation of the reaction and elastic differential cross sections of various projectile-target collisions at low and intermediate energies. Through a systematic study, we find that the inclusion of the finite range interaction and Coulomb modifications plays very important role in the Glauber theory to reproduce the experimental data at these energy ranges. Usually the effect of the Coulomb modification is to decrease the reaction cross sections, on the contrary that of the finite range interaction modification increases them. The angular distributions calculated by the Glauber theory including these two corrections are in good agreement with the experimental data.``

  18. Observation of high energy gamma rays in intermediate energy nucleus-nucleus collisions

    NARCIS (Netherlands)

    Beard, K.B.; Benenson, W.; Bloch, C.; Kashy, E.; Stevenson, J.; Morrissey, D.J.; Plicht, J. van der; Sherrill, B.; Winfield, J.S.

    1985-01-01

    High energy electrons and positrons observed in medium energy nucleus-nucleus collisions are shown to be primarily due to the external conversion of high energy gamma rays. The reaction 14N+Cu was studied at E/A=40 MeV, and a magnetic spectrograph was used with a specially constructed multiwire prop

  19. Temperature measurement of quark-gluon plasma formed in high energy nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    We discuss lepton pair and real photon emission from quark-gluon plasma, which is very likely to be formed in high energy nucleus-nucleus collisions. Measurement of pair production cross-section will provide one with accurate information of the temperature of this plasma. (author)

  20. Insulin increases sympathetic nerve activity in part by suppression of tonic inhibitory neuropeptide Y inputs into the paraventricular nucleus in female rats.

    Science.gov (United States)

    Cassaglia, Priscila A; Shi, Zhigang; Brooks, Virginia L

    2016-07-01

    Following binding to receptors in the arcuate nucleus (ArcN), insulin increases sympathetic nerve activity (SNA) and baroreflex control of SNA via a pathway that includes the paraventricular nucleus of the hypothalamus (PVN). Previous studies in males indicate that the sympathoexcitatory response is mediated by α-melanocyte stimulating hormone (α-MSH), which binds to PVN melanocortin type 3/4 receptors (MC3/4R). The present study was conducted in α-chloralose-anesthetized female rats to test the hypothesis that suppression of inhibitory neuropeptide Y (NPY) inputs to the PVN is also involved. In support of this, blockade of PVN NPY Y1 receptors with BIBO 3304 (NPY1x), ArcN insulin nanoinjections, and PVN NPY1x followed by ArcN insulin each increased lumbar SNA (LSNA) and its baroreflex regulation similarly. Moreover, prior PVN injections of NPY blocked the sympathoexcitatory effects of ArcN insulin. Finally, PVN nanoinjections of the MC3/4R inhibitor SHU9119 prevented both the acute (15 min) and longer, more slowly developing (60 min), increases in LSNA in response to ArcN insulin. In conclusion, in females, ArcN insulin increases LSNA, in part, by suppressing tonic PVN NPY inhibition, which unmasks excitatory α-MSH drive of LSNA. Moreover, the steadily increasing rise in LSNA induced by ArcN insulin is also dependent on PVN MC3/4R. PMID:27122366

  1. Protein quality control in the nucleus.

    Science.gov (United States)

    Jones, Ramon D; Gardner, Richard G

    2016-06-01

    The nucleus is the repository for the eukaryotic cell's genetic blueprint, which must be protected from harm to ensure survival. Multiple quality control (QC) pathways operate in the nucleus to maintain the integrity of the DNA, the fidelity of the DNA code during replication, its transcription into mRNA, and the functional structure of the proteins that are required for DNA maintenance, mRNA transcription, and other important nuclear processes. Although we understand a great deal about DNA and RNA QC mechanisms, we know far less about nuclear protein quality control (PQC) mechanisms despite that fact that many human diseases are causally linked to protein misfolding in the nucleus. In this review, we discuss what is known about nuclear PQC and we highlight new questions that have emerged from recent developments in nuclear PQC studies. PMID:27015023

  2. The nucleus: a black box being opened.

    Science.gov (United States)

    van Driel, R; Humbel, B; de Jong, L

    1991-12-01

    Until recently our knowledge about the structural and functional organization of the cell nucleus was very limited. Recent technical developments in the field of ultrastructural analysis, combined with ongoing research on the properties of the nuclear matrix, give new insight into how the nucleus is structured. Two types of observations shape our ideas about nuclear organization. First, most nuclear functions (replication, transcription, RNA processing, and RNA transport) are highly localized within the nucleus, rather than diffusely distributed. Moreover, they are associated with the nuclear matrix. Second, chromatin is organized in discrete loops, bordered by nuclear matrix attachment sequences (MARs). Each loop may contain one or several genes. The arrangement of chromatin in loops has profound consequences for the regulation of gene expression.

  3. Expression of calcitonin gene-related peptide in efferent vestibular system and vestibular nucleus in rats with motion sickness.

    Directory of Open Access Journals (Sweden)

    Wang Xiaocheng

    Full Text Available UNLABELLED: Motion sickness presents a challenge due to its high incidence and unknown pathogenesis although it is a known fact that a functioning vestibular system is essential for the perception of motion sickness. Recent studies show that the efferent vestibular neurons contain calcitonin gene-related peptide (CGRP. It is a possibility that the CGRP immunoreactivity (CGRPi fibers of the efferent vestibular system modulate primary afferent input into the central nervous system; thus, making it likely that CGRP plays a key role in motion sickness. To elucidate the relationship between motion sickness and CGRP, the effects of CGRP on the vestibular efferent nucleus and the vestibular nucleus were investigated in rats with motion sickness. METHODS: An animal model of motion sickness was created by subjecting rats to rotary stimulation for 30 minutes via a trapezoidal stimulation pattern. The number of CGRPi neurons in the vestibular efferent nucleus at the level of the facial nerve genu and the expression level of CGRPi in the vestibular nucleus of rats were measured. Using the ABC method of immunohistochemistry technique, measurements were taken before and after rotary stimulation. The effects of anisodamine on the expression of CGRP in the vestibular efferent nucleus and the vestibular nucleus of rats with motion sickness were also investigated. RESULTS AND DISCUSSION: Both the number of CGRPi neurons in the vestibular efferent nucleus and expression level in the vestibular nucleus increased significantly in rats with motion sickness compared to that of controls. The increase of CGRP expression in rats subjected to rotary stimulation 3 times was greater than those having only one-time stimulation. Administration of anisodamine decreased the expression of CGRP within the vestibular efferent nucleus and the vestibular nucleus in rats subjected to rotary stimulation. In conclusion, CGRP possibly plays a role in motion sickness and its mechanism

  4. UNCOVERING THE NUCLEUS CANDIDATE FOR NGC 253

    Energy Technology Data Exchange (ETDEWEB)

    Günthardt, G. I.; Camperi, J. A. [Observatorio Astronómico, Universidad Nacional de Córdoba (Argentina); Agüero, M. P. [Observatorio Astronómico, Universidad Nacional de Córdoba, and CONICET (Argentina); Díaz, R. J.; Gomez, P. L.; Schirmer, M. [Gemini Observatory, AURA (United States); Bosch, G., E-mail: gunth@oac.uncor.edu, E-mail: camperi@oac.uncor.edu, E-mail: mpaguero@oac.uncor.edu, E-mail: rdiaz@gemini.edu, E-mail: pgomez@gemini.edu, E-mail: mschirmer@gemini.edu, E-mail: guille@fcaglp.unlp.edu.ar [Instituto de Astrofísica de La Plata (CONICET-UNLP) (Argentina)

    2015-11-15

    NGC 253 is the nearest spiral galaxy with a nuclear starburst that becomes the best candidate for studying the relationship between starburst and active galactic nucleus activity. However, this central region is veiled by large amounts of dust, and it has been so far unclear which is the true dynamical nucleus to the point that there is no strong evidence that the galaxy harbors a supermassive black hole co-evolving with the starburst as was supposed earlier. Near-infrared (NIR) spectroscopy, especially NIR emission line analysis, could be advantageous in shedding light on the true nucleus identity. Using Flamingos-2 at Gemini South we have taken deep K-band spectra along the major axis of the central structure and through the brightest infrared source. In this work, we present evidence showing that the brightest NIR and mid-infrared source in the central region, already known as radio source TH7 and so far considered just a large stellar supercluster, in fact presents various symptoms of a genuine galactic nucleus. Therefore, it should be considered a valid nucleus candidate. Mentioning some distinctive aspects, it is the most massive compact infrared object in the central region, located at 2.″0 of the symmetry center of the galactic bar, as measured in the K-band emission. Moreover, our data indicate that this object is surrounded by a large circumnuclear stellar disk and it is also located at the rotation center of the large molecular gas disk of NGC 253. Furthermore, a kinematic residual appears in the H{sub 2} rotation curve with a sinusoidal shape consistent with an outflow centered in the candidate nucleus position. The maximum outflow velocity is located about 14 pc from TH7, which is consistent with the radius of a shell detected around the nucleus candidate, observed at 18.3 μm (Qa) and 12.8 μm ([Ne ii]) with T-ReCS. Also, the Brγ emission line profile shows a pronounced blueshift and this emission line also has the highest equivalent width at this

  5. Effects of Zuogui Wan on neurocyte apoptosis and down-regulation of TGF-β1 expression in nuclei of arcuate hypothalamus of monosodium glutamate -liver regeneration rats

    Institute of Scientific and Technical Information of China (English)

    Han-Min Li; Xiang Gao; Mu-Lan Yang; Jia-Jun Mei; Liu-Tong Zhang; Xing-Fan Qiu

    2004-01-01

    AIM: To inquire into the effects and mechanism of Zuogui Wan (Pills for Kidney Yin) on neurocyte apoptosis in nuclei of arcuate hypothalamus (ARN) of monosodium glutamate(MSG)-liver regeneration rats, and the mechanism of liver regeneration by using optic microscope, electron microscope and in situ end labeling technology to adjust nerve-endocrineimmunity network.METHODS: Neurocyte apoptosis in ARN of the experiment rats was observed by using optic microscope, electron microscope andin situ end labeling technology. Expression of TGF-β1 in ARN was observed by using immunohistochemistry method.RESULTS: The expression of TGF-β1 in rats of model group was increased with the increase of ARN neurocyte apoptosis index (AI) (t = 8.3097, 12.9884, P<0.01). As compared with the rats of model group, the expression of TGF-β1 in rats of Zuogui Wan treatment group was decreased with the significant decrease of ARN neurocyte apoptosis (t = 4.5624,11.1420, P<0.01).CONCLUSION: Brain neurocyte calcium ion overexertion and TGF-β1 protein participate in the adjustment and control of ARN neurocyte apoptosis in MSG-liver regeneration-rats. Zuogui Wan can prevent ARN neurocyte apoptosis of MSG-liver regeneration in rats by downregulating the expression of TGF-β1, and influence liver regeneration through adjusting nerve-endocrine-immune network.

  6. Complex Proterozoic crustal assembly of southwestern North America in an arcuate subduction system:Tthe Black Canyon of the Gunnison, southwestern Colorado

    Science.gov (United States)

    Jessup, Micah J.; Kalstrom, Karl E.; Connelly, James; Williams, Michael; Livaccari, Richard; Tyson, Amanda; Rogers, Steven A.

    The dominant orogenic fabric in Proterozoic rocks of the southwestern U.S. includes a series of NE-striking shear zones that are commonly interpreted as suture zones across which blocks of juvenile crust were assembled to the southern margin of Laurentia. New structural and geochronological data from southwestern Colorado suggest that fabrics related to assembly of tectonostratigraphic terranes in this area strike northwest. The NW-striking foliations represent deformation at ca. 10-20 km paleodepths (ca. 1.77-1.71 Ga), and are parallel to magnetic anomalies and to gradients in mantle velocity structure. The agreement between these data sets suggests that the NW-striking structures are important at lithospheric scale, extend to >100 km depth, and may record assembly of southwestern Colorado across NW-striking tectonic boundaries. Geochronologic data indicate that northwest (central Colorado)—and northeast (Cheyenne belt)—striking boundaries developed simultaneously during accretion of southwestern Laurentia between ca. 1.78-1.73 Ga. We propose that the Yavapai province at ca. 1.75 Ga may have involved a complex arcuate subduction system, with multiple arcs, analogous to that of the modern Banda Sea, in the Indonesia region.

  7. Optogenetically-induced tonic dopamine release from VTA-nucleus accumbens projections inhibits reward consummatory behaviors.

    Science.gov (United States)

    Mikhailova, Maria A; Bass, Caroline E; Grinevich, Valentina P; Chappell, Ann M; Deal, Alex L; Bonin, Keith D; Weiner, Jeff L; Gainetdinov, Raul R; Budygin, Evgeny A

    2016-10-01

    Recent optogenetic studies demonstrated that phasic dopamine release in the nucleus accumbens may play a causal role in multiple aspects of natural and drug reward-related behaviors. The role of tonic dopamine release in reward consummatory behavior remains unclear. The current study used a combinatorial viral-mediated gene delivery approach to express ChR2 on mesolimbic dopamine neurons in rats. We used optical activation of this dopamine circuit to mimic tonic dopamine release in the nucleus accumbens and to explore the causal relationship between this form of dopamine signaling within the ventral tegmental area (VTA)-nucleus accumbens projection and consumption of a natural reward. Using a two bottle choice paradigm (sucrose vs. water), the experiments revealed that tonic optogenetic stimulation of mesolimbic dopamine transmission significantly decreased reward consummatory behaviors. Specifically, there was a significant decrease in the number of bouts, licks and amount of sucrose obtained during the drinking session. Notably, activation of VTA dopamine cell bodies or dopamine terminals in the nucleus accumbens resulted in identical behavioral consequences. No changes in water intake were evident under the same experimental conditions. Collectively, these data demonstrate that tonic optogenetic stimulation of VTA-nucleus accumbens dopamine release is sufficient to inhibit reward consummatory behavior, possibly by preventing this circuit from engaging in phasic activity that is thought to be essential for reward-based behaviors.

  8. Direct projection from the suprachiasmatic nucleus to hypophysiotrophic corticotropin-releasing factor immunoreactive cells in the paraventricular nucleus of the hypothalamus demonstrated...

    DEFF Research Database (Denmark)

    Vrang, N.; Larsen, P.J.; Mikkelsen, J.D.

    1995-01-01

    Suprachiasmatic nucleus, paraventricular nucleus, circadian rhythms, phaseolus vulgaris-leucoagglutinin, corticotropin-releasing factor, dual immunocytochemistry......Suprachiasmatic nucleus, paraventricular nucleus, circadian rhythms, phaseolus vulgaris-leucoagglutinin, corticotropin-releasing factor, dual immunocytochemistry...

  9. Inner Structure of Boiling Nucleus and Interfacial Energy Between Nucleus and Bulk Liquid

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Dong; TIAN Yong; PENG Xiao-Feng; WANG Bu-Xuan

    2004-01-01

    @@ A model of two-region structure of a nucleus is proposed to describe nucleus evolution. The interfacial tension between bulk liquid phase and nucleus is dependent on the density gradient in the transition region and varies with the structure change of the transition region. With the interfacial tension calculated using this model, the predicted nucleation rate is very close to the experimental measurement. Furthermore, this model and associated analysis provide solid theoretical evidence to clarify the definition of nucleation rate and understand the nucleation phenomenon with insight into the physical nature.

  10. Nucleus-Nucleus Potential at Near-Barrier Energies from Self Consistent Calculations

    CERN Document Server

    Skalski, J

    2003-01-01

    We determine the static nucleus-nucleus potential from Hartree-Fock (HF) calculations with the Skyrme interaction. To this aim, HF equations are solved on a spatial mesh, with the initial configuration consisting of target and projectile positioned at various relative distances. For a number of reaction partners, the calculated barrier heights reasonably well compare with those extracted from the measured fusion and capture cross sections. At smaller target-projectile distances, our results show the intrinsic barriers to heavy compound nucleus formation. We speculate on their possible connection with the fusion hindrance observed for large Z sub T Z sub P.

  11. An organism arises from every nucleus.

    Directory of Open Access Journals (Sweden)

    Nurullah Keklikoglu

    2009-12-01

    Full Text Available The fact that, cloning using somatic cell nuclear transfer (SCNT method has been performed, opened new horizons for cloning, and changed the way of our understanding and approach to cell and nucleus. The progress in cloning technology, brought the anticipation of the ability to clone an organism from each somatic cell nucleus. Therefore, the 'Cell Theory' is about to take the additional statement as "An organism arises from every nucleus". The development of gene targeting procedures which can be applied with SCNT, showed us that it may be possible to obtain different versions of the original genetic constitution of a cell. Because of this opportunity which is provided by SCNT, in reproductive cloning, it would be possible to clone enhanced organisms which can adapt to different environmental conditions and survive. Furthermore, regaining the genetic characteristics of ancestors or reverse herediter variations would be possible. On the other hand, in therapeutic cloning, more precise and easily obtainable alternatives for cell replacement therapy could be presented. However, while producing healthier or different organisms from a nucleus, it is hard to foresee the side effects influencing natural processes in long term is rather difficult.

  12. ULTRASTRUCTURE OF THE RAT MESENCEPHALIC TRIGEMINAL NUCLEUS

    NARCIS (Netherlands)

    LIEM, RSB; COPRAY, JCVM; VANWILLIGEN, JD

    1991-01-01

    The subcellular morphology of the mesencephalic trigeminal (Me5) nucleus in the rat was studied by transmission electron microscopy. Most neurons in the thin rostral as well as in the major caudal part of Me5 appeared as large (40-50-mu-m), round-to ovoid-shaped unipolar cells. A few neurons (estima

  13. Neutrino-Nucleus Reactions and Muon Capture in 12C

    CERN Document Server

    Krmpotic, F; Mariano, A; Mariano, and A.

    2004-01-01

    The neutrino-nucleus cross section and the muon capture rate are discussed within a simple formalism which facilitates the nuclear structure calculations. The corresponding formulae only depend on four types of nuclear matrix elements, which are currently used in the nuclear beta decay. We have also considered the non-locality effects arising from the velocity-dependent terms in the hadronic current. We show that for both observables in 12C the higher order relativistic corrections are of the order of ~5 only, and therefore do not play a significant role. As nuclear model framework we use the projected QRPA (PQRPA) and show that the number projection plays a crucial role in removing the degeneracy between the proton-neutron two quasiparticle states at the level of the mean field. Comparison is done with both the experimental data and the previous shell model calculations. Possible consequences of the present study on the determination of the $\

  14. Neuropeptide Y activity in the nucleus accumbens modulates feeding behavior and neuronal activity

    NARCIS (Netherlands)

    van den Heuvel, José K; Furman, Kara; Gumbs, Myrtille C R; Eggels, Leslie; Opland, Darren M; Land, Benjamin B; Kolk, Sharon M; S Narayanan, Nandakumar; Fliers, Eric; Kalsbeek, A.; DiLeone, Ralph J; la Fleur, Susanne E

    2015-01-01

    BACKGROUND: Neuropeptide Y (NPY) is a hypothalamic neuropeptide that plays a prominent role in feeding and energy homeostasis. Expression of the NPY Y1 receptor (Y1R) is highly concentrated in the nucleus accumbens (Acb), a region important in the regulation of palatable feeding. In this study, we p

  15. Role of nucleus accumbens glutamatergic plasticity in drug addiction

    OpenAIRE

    Quintero GC

    2013-01-01

    Gabriel C Quintero1–31Florida State University – Panama, Clayton, Panama; 2Medical University of South Carolina, Charleston, South Carolina, USA; 3Smithsonian Tropical Research Institute, Ancon, Republic of PanamaAbstract: Substance dependence is characterized by a group of symptoms, according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR). These symptoms include tolerance, withdrawal, drug consumption for alleviating w...

  16. Stereotactic localization and visualization of the subthalamic nucleus

    Institute of Scientific and Technical Information of China (English)

    SHEN Wei-gao; WANG Hai-yang; LIN Zhi-guo; SHEN Hong; CHEN Xiao-guang; FU Yi-li; GAO Wen-peng

    2009-01-01

    Background The subthalamic nucleus (STN) is widely recognized as one of the most important and commonly targeted nuclei in stereotactic and functional neurosurgery. The success of STN surgery depends on accuracy in target determination. Construction of a digitalized atlas of STN based on stereotactic MRI will play an instrumental role in the accuracy of anatomical localization. The aim of this study was to investigate the three-dimensional (3D) target location of STN in stereotactic space and construct a digitalized atlas of STN to accomplish the visualization of the STN on stereotactic MRI, thus providing clinical guidance on the precise anatomical localization of STN.Methods One hundred and twenty healthy people volunteered to be scanned by 1.5 Tesla MRI scanning with 1-mm-thick slice in the standard stereotactic space between 2005 and 2006. One adult male was selected for 3D reconstruction of STN. The precess of 3D reconstruction included identification, manual segmentation, extraction,conservation and reconstruction.Results There was a significant correlation between the coordinates and age (P <0.05). The volume of left STN was significantly larger than the right STN, and there was a significant negative correlation between volume and age (P <0.05).The surface of the STN nucleus after 3D reconstruction appeared smooth, natural and realistic. The morphological feature of STN on the individual brain could be visualized directly in 3D. The 3D reconstructed STN could be rotated,zoomed and displayed at any direction in the stereotactic space. The anteroposterior diameter of the STN nucleus was longer than the vertical and transverse diameters in 3D space. The 3D reconstruction of STN manifested typical structure of the "dual lens".Conclusions The visualization of individual brain atlas based on stereotactic MRI is feasible. However, software for automated segmentation, extraction and registration of MR images need to be further developed.

  17. Tractography patterns of subthalamic nucleus deep brain stimulation.

    Science.gov (United States)

    Vanegas-Arroyave, Nora; Lauro, Peter M; Huang, Ling; Hallett, Mark; Horovitz, Silvina G; Zaghloul, Kareem A; Lungu, Codrin

    2016-04-01

    Deep brain stimulation therapy is an effective symptomatic treatment for Parkinson's disease, yet the precise mechanisms responsible for its therapeutic effects remain unclear. Although the targets of deep brain stimulation are grey matter structures, axonal modulation is known to play an important role in deep brain stimulation's therapeutic mechanism. Several white matter structures in proximity to the subthalamic nucleus have been implicated in the clinical benefits of deep brain stimulation for Parkinson's disease. We assessed the connectivity patterns that characterize clinically beneficial electrodes in Parkinson's disease patients, after deep brain stimulation of the subthalamic nucleus. We evaluated 22 patients with Parkinson's disease (11 females, age 57 ± 9.1 years, disease duration 13.3 ± 6.3 years) who received bilateral deep brain stimulation of the subthalamic nucleus at the National Institutes of Health. During an initial electrode screening session, one month after deep brain stimulation implantation, the clinical benefits of each contact were determined. The electrode was localized by coregistering preoperative magnetic resonance imaging and postoperative computer tomography images and the volume of tissue activated was estimated from stimulation voltage and impedance. Brain connectivity for the volume of tissue activated of deep brain stimulation contacts was assessed using probabilistic tractography with diffusion-tensor data. Areas most frequently connected to clinically effective contacts included the thalamus, substantia nigra, brainstem and superior frontal gyrus. A series of discriminant analyses demonstrated that the strength of connectivity to the superior frontal gyrus and the thalamus were positively associated with clinical effectiveness. The connectivity patterns observed in our study suggest that the modulation of white matter tracts directed to the superior frontal gyrus and the thalamus is associated with favourable clinical

  18. Two different modes associated with the composite nucleus- the charge and mass distributions for exotic nuclear synthesis -

    Directory of Open Access Journals (Sweden)

    Itagaki N.

    2010-03-01

    Full Text Available The mass-dependent structure of the composite nucleus is shown based on three-dimensional timedependent Hartree-Fock calculations with Skyrme interactions (SLy4d and SkM*. One remarkable result is that the isovector monopole excitation dominantly appears for collisions of heavy nuclei, and the isovector dipole excitation for those of light ones. Such a difference found in the dynamical structure of composite nucleus plays a role in the equilibration of charge.

  19. Hypoxia activates nucleus tractus solitarii neurons projecting to the paraventricular nucleus of the hypothalamus

    OpenAIRE

    King, T. Luise; Heesch, Cheryl M.; Clark, Catharine G.; Kline, David D.; Hasser, Eileen M.

    2012-01-01

    Peripheral chemoreceptor afferent information is sent to the nucleus tractus solitarii (nTS), integrated, and relayed to other brain regions to alter cardiorespiratory function. The nTS projects to the hypothalamic paraventricular nucleus (PVN), but activation and phenotype of these projections during chemoreflex stimulation is unknown. We hypothesized that activation of PVN-projecting nTS neurons occurs primarily at high intensities of hypoxia. We assessed ventilation and cardiovascular para...

  20. Forward-backward correlations in nucleus-nucleus collisions: baseline contributions from geometrical fluctuations

    OpenAIRE

    Konchakovski, V. P.; Hauer, M.; Torrieri, G.; Gorenstein, M. I.; Bratkovskaya, E. L.

    2008-01-01

    We discuss the effects of initial collision geometry and centrality bin definition on correlation and fluctuation observables in nucleus-nucleus collisions. We focus on the forward-backward correlation coefficient recently measured by the STAR Collaboration in Au+Au collisions at RHIC. Our study is carried out within two models: the Glauber Monte Carlo code with a `toy' wounded nucleon model and the hadron-string dynamics (HSD) transport approach. We show that strong correlations can arise du...

  1. Study of -nucleus interaction through the formation of -nucleus bound state

    Indian Academy of Sciences (India)

    V Jha; B J Roy; A Chatterjee; H Machner

    2006-05-01

    The question of possible existence of -mesic nuclei is quite intriguing. Answer to this question will deeply enrich our understanding of -nucleus interaction which is not so well-understood. We review the experimental efforts for the search of -mesic nuclei and describe the physics motivation behind it. We present the description of an experiment for the search of -nucleus bound state using the GeV proton beam, currently being performed at COSY.

  2. Centrality Dependence of Flow in High-Energy Nucleus-Nucleus Collisions

    Institute of Scientific and Technical Information of China (English)

    杨红艳; 周代翠; 杨纯斌; 蔡勖

    2002-01-01

    Directed flow and elliptic flow of final state particles in high-energy nucleus-nucleus collisions in the EMU01 experiment have been studied. The dependences of directed flow and elliptic flow on incident energy and impact centrality of outgoing particles are presented. The results exhibit strong dependence of flow on centrality and energy. We also suggest a more reliable way to determine the event plane resolution here.

  3. Fusion cross sections for reactions involving medium & heavy nucleus-nucleus systems

    OpenAIRE

    Atta, Debasis; Basu, D. N.

    2014-01-01

    Existing data on near-barrier fusion excitation functions of medium and heavy nucleus-nucleus systems have been analyzed using a simple diffused barrier formula derived assuming the Gaussian shape of the barrier height distributions. Fusion cross section is obtained by folding the Gaussian barrier distribution with the classical expression for the fusion cross section for a fixed barrier. The energy dependence of the fusion cross section, thus obtained, provides good description to the existi...

  4. β-Catenin Can Be Transported into the Nucleus in a Ran-unassisted Manner

    OpenAIRE

    Yokoya, Fumihiko; Imamoto, Naoko; Tachibana, Taro; Yoneda, Yoshihiro

    1999-01-01

    The nuclear accumulation of β-catenin plays an important role in the Wingless/Wnt signaling pathway. This study describes an examination of the nuclear import of β-catenin in living mammalian cells and in vitro semi-intact cells. When injected into the cell cytoplasm, β-catenin rapidly migrated into the nucleus in a temperature-dependent and wheat germ agglutinin–sensitive manner. In the cell-free import assay, β-catenin rapidly migrates into the nucleus without the exogenous addition of cyto...

  5. Ion-Ion Correlation Effect on the Neutrino-Nucleus Scattering in Supernova Cores

    OpenAIRE

    Itoh, Naoki; Asahara, Ryohei; Tomizawa, Nami; Wanajo, Shinya; Nozawa, Satoshi

    2004-01-01

    We calculate the ion-ion correlation effect on the neutrino-nucleus scattering in supernova cores, which is an important opacity source for the neutrinos and plays a vital role in the supernova explosion. In order to calculate the ion-ion correlation effect we use the results of the improved hypernetted-chain method calculations of the classical one-component plasma. As in the preceding studies on this effect, we find a dramatic decrease of the effective neutrino-nucleus scattering cross sect...

  6. Neurophysiological evidence for the presence of cannabinoid CB1 receptors in the laterodorsal tegmental nucleus

    DEFF Research Database (Denmark)

    Soni, Neeraj; Satpathy, Shankha; Kohlmeier, Kristi Anne

    2014-01-01

    Marijuana, which acts within the endocannabinoid (eCB) system as an agonist of the cannabinoid type 1 receptor (CB1R), exhibits addictive properties and has powerful actions on the state of arousal of an organism. The laterodorsal tegmental nucleus (LDT), as a component of the reticular activating...... the firing frequency and synaptic activity of neurons in this nucleus. Therefore, endogenous eCB transmission could play a role in processes involving the LDT, such as cortical activation and motivated behaviours and, further, behavioural actions of marijuana are probably mediated, in part, via cellular...

  7. Multiple-scattering effects in proton- and alpha-nucleus reactions with Glauber theory

    International Nuclear Information System (INIS)

    We study the total reaction and elastic differential cross sections for proton-nucleus and 4He-nucleus reactions in the framework of the Glauber theory which describes multiplescattering processes. The input wave functions are obtained using the Skyrme-Hartree-Fock method and prepared for a wide range of mass numbers, O, Ca, Ni, Sn, and Pb isotopes. The theory reproduces experimental data very well. An effect of the multiple scattering is discussed by comparing with a standard optical-limit approximation. We see that the multiple-scattering effects play a crucial role, especially in enhancing the elastic differential cross sections at large scattering angles

  8. Transverse momentum spectra in high-energy nucleus-nucleus, proton-nucleus and proton-proton collisions

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Jie

    2011-01-01

    The transverse momentum distributions of final-state particles produced in nucleus-nucleus (AA),proton-nucleus (pA),and proton-proton (pp) collisions at high energies are investigated using a multisource ideal gas model.Our calculated results show that the contribution of hard emission can be neglected in the study of transverse momentum spectra of charged pions and kaons produced in Cu-Cu collisions at (√SNN)=22.5 GeV.And if we consider the contribution of hard emission,the transverse momentum spectra of p and (P) produced in Cu-Cu collisions at (√SNN)=22.5 GeV,KsO produced in Pb-Pb collisions at 158 A GeV,J/ψ particles produced in p-Pb collisions at 400 GeV and π+,K+,p produced in proton-proton collisions at (√S)=200 GeV,can be described by the model,especially in the tail part of spectra.

  9. Formation of the avian nucleus magnocellularis from the auditory anlage.

    Science.gov (United States)

    Hendricks, Susan J; Rubel, Edwin W; Nishi, Rae

    2006-10-01

    In the avian auditory system, the neural network for computing the localization of sound in space begins with bilateral innervation of nucleus laminaris (NL) by nucleus magnocellularis (NM) neurons. We used antibodies against the neural specific markers Hu C/D, neurofilament, and SV2 together with retrograde fluorescent dextran labeling from the contralateral hindbrain to identify NM neurons within the anlage and follow their development. NM neurons could be identified by retrograde labeling as early as embryonic day (E) 6. While the auditory anlage organized itself into NM and NL in a rostral-to-caudal fashion between E6 and E8, labeled NM neurons were visible throughout the extent of the anlage at E6. By observing the pattern of neuronal rearrangements together with the pattern of contralaterally projecting NM fibers, we could identify NL in the ventral anlage. Ipsilateral NM fibers contacted the developing NL at E8, well after NM collaterals had projected contralaterally. Furthermore, the formation of ipsilateral connections between NM and NL neurons appeared to coincide with the arrival of VIIIth nerve fibers in NM. By E10, immunoreactivity for SV2 was heavily concentrated in the dorsal and ventral neuropils of NL. Thus, extensive pathfinding and morphological rearrangement of central auditory nuclei occurs well before the arrival of cochlear afferents. Our results suggest that NM neurons may play a central role in formation of tonotopic connections in the auditory system.

  10. Hypocretinergic facilitation of synaptic activity of neurons in the nucleus pontis oralis of the cat.

    Science.gov (United States)

    Xi, Ming Chu; Fung, Simon J; Yamuy, Jack; Morales, Francisco R; Chase, Michael H

    2003-06-27

    The present study was undertaken to explore the neuronal mechanisms of hypocretin actions on neurons in the nucleus pontis oralis (NPO), a nucleus which plays a key role in the generation of active (REM) sleep. Specifically, we sought to determine whether excitatory postsynaptic potentials (EPSPs) evoked by stimulation of the laterodorsal tegmental nucleus (LDT) and spontaneous EPSPs in NPO neurons are modulated by hypocretin. Accordingly, recordings were obtained from NPO neurons in the cat in conjunction with the juxtacellular microinjection of hypocretin-1 onto intracellularly recorded cells. The application of hypocretin-1 significantly increased the mean amplitude of LDT-evoked EPSPs of NPO neurons. In addition, the frequency and the amplitude of spontaneous EPSPs in NPO neurons increased following hypocretin-1 administration. These data suggest that hypocretinergic processes in the NPO are capable of modulating the activity of NPO neurons that receive excitatory cholinergic inputs from neurons in the LDT. PMID:12763260

  11. Both Estrogen and Androgen Modify the Response to Activation of Neurokinin-3 and κ-Opioid Receptors in Arcuate Kisspeptin Neurons From Male Mice.

    Science.gov (United States)

    Ruka, Kristen A; Burger, Laura L; Moenter, Suzanne M

    2016-02-01

    Gonadal steroids regulate the pattern of GnRH secretion. Arcuate kisspeptin (kisspeptin, neurokinin B, and dynorphin [KNDy]) neurons may convey steroid feedback to GnRH neurons. KNDy neurons increase action potential firing upon the activation of neurokinin B receptors (neurokinin-3 receptor [NK3R]) and decrease firing upon the activation of dynorphin receptors (κ-opioid receptor [KOR]). In KNDy neurons from intact vs castrated male mice, NK3R-mediated stimulation is attenuated and KOR-mediated inhibition enhanced, suggesting gonadal secretions are involved. Estradiol suppresses spontaneous GnRH neuron firing in male mice, but the mediators of the effects on firing in KNDy neurons are unknown. We hypothesized the same gonadal steroids affecting GnRH firing pattern would regulate KNDy neuron response to NK3R and KOR agonists. To test this possibility, extracellular recordings were made from KNDy neurons in brain slices from intact, untreated castrated or castrated adult male mice treated in vivo with steroid receptor agonists. As observed previously, the stimulation of KNDy neurons by the NK3R agonist senktide was attenuated in intact vs castrated mice and suppression by dynorphin was enhanced. In contrast to observations of steroid effects on the GnRH neuron firing pattern, both estradiol and DHT suppressed senktide-induced KNDy neuron firing and enhanced the inhibition caused by dynorphin. An estrogen receptor-α agonist but not an estrogen receptor-β agonist mimicked the effects of estradiol on NK3R activation. These observations suggest the steroid modulation of responses to activation of NK3R and KOR as mechanisms for negative feedback in KNDy neurons and support the contribution of these neurons to steroid-sensitive elements of a GnRH pulse generator.

  12. Role of hypothalamus nociceptin/orphanin FQ in pre-ovulatory luteinizing hormone surge of estrogen and progesterone-primed, ovariectomized rats

    Institute of Scientific and Technical Information of China (English)

    Xiao-fei AN; Jiang-yi YU; Yi FENG; Bo-ying CHEN; Su-lin ZHANG

    2007-01-01

    Aim: To investigate the role of hypothalamus nociceptin/orphanin FQ (OFQ) and its endogenous receptor, the opioid receptor-likel receptor (ORL1 receptor) in the estrus cycle of female rats. Method: Radioimmunoassay was used to detect the effect of the intracerebroventricular (icv) administration of OFQ and/or the ORL1 receptor antagonist [Nphel]Nociceptin(1-13)NH2 that is, NC13 on luteinizing hormone (LH) levels of estrogen- and progesterone (EBP)-primed, ovariectomized (OVX) rats (EBP-primed OVX rats). RT-PCR, Western blotting, and immunohis- tochemistry techniques were adopted to observe the changes of OFQ and the ORL1 receptor in the pre-optic area (POA) and the medial basal hypothalamus (MBH) of the estrus cycle of female rat. Results: Pre-ovulatory LH surges in EBP-primed, OVX rats were significantly reduced by icv administration of 20 and 200 nmol OFQ (P<0.05), and the effect of 20 nmol OFQ could be abolished by pretreat-ment with 20 nmol NC13. The OFQ mRNA level in the POA on pro-estrus was lowered markedly compared to diestrus and estrus (P<0.05), while the mRNA and protein levels of the ORL1 receptor showed no significant changes in the POA and MBH across the estrus cycle. Meanwhile, the number of OFQ-immunoreac-tive neurons in the medial POA, ventromedial hypothalamus, and the arcuate nucleus on pro-estrus was significantly decreased compared to diestrus and es-trus (P<0.05). Conclusion: The inhibitory effect of OFQ on the LH surge of EBP-primed, OVX rats and its downregulation in POA and MBH on pro-estrus sug-gests that it might play a negative modulatory role in the estrus cycle.

  13. Different discharge properties of facial nucleus motoneurons following neurotmesis in a rat model.

    Science.gov (United States)

    Shi, Suming; Xu, Lei; Li, Jianfeng; Han, Yuechen; Wang, Haibo

    2016-08-26

    Facial nucleus motoneurons innervating the facial expressive muscles are involved in a wide range of motor activities, however, the types of movement related neurons and their electrophysiological transformation after peripheral facial nerve injury haven't been revealed. This study was designed to elucidate the types of facial nucleus motoneurons and their alterations of discharge parameters following peripheral facial nerve injury in vivo. Here we set up a rat model by implanting electrode arrays into the brainstem and recorded the electrophysiological signals of facial nucleus neurons in the intact rats for 5 days, then transected the trunk of facial nerve (TF), and continued the record for 4 weeks. At the 4th week post-surgery, the morphological changes of TFs were analyzed. In this paper, we described two types of putative facial nucleus motoneurons based on their electrophysiological properties and their firing frequency adaptation. Type I motoneurons (n=57.6%) were characterized by a sustained spike adaptation, Type II motoneurons (n=26.2%) were identified by a phasic fast spike firing. Facial palsy and synkinesia, caused by neurotmesis of TF, were accompanied by firing rates reduction and firing pattern alteration of motoneurons. Our findings suggest the presence of two types of facial nucleus motorneurons, and their response patterns after neurotmesis support the notion that the discharge pattern of motorneurons may play an important role in the facial nerve function. PMID:27423319

  14. Energy and Mass-Number Dependence of Hadron-Nucleus Total Reaction Cross Sections

    Science.gov (United States)

    Kohama, Akihisa; Iida, Kei; Oyamatsu, Kazuhiro

    2016-09-01

    We thoroughly investigate how proton-nucleus total reaction cross sections depend on the target mass number A and the proton incident energy. In doing so, we systematically analyze nuclear reaction data that are sensitive to nuclear size, namely, proton-nucleus total reaction cross sections and differential elastic cross sections, using a phenomenological black-sphere approximation of nuclei that we are developing. In this framework, the radius of the black sphere is found to be a useful length scale that simultaneously accounts for the observed proton-nucleus total reaction cross section and first diffraction peak in the proton elastic differential cross section. This framework, which is shown here to be applicable to antiprotons, is expected to be applicable to any kind of projectile that is strongly attenuated in the nucleus. On the basis of a cross-section formula constructed within this framework, we find that a less familiar A1/6 dependence plays a crucial role in describing the energy dependence of proton-nucleus total reaction cross sections.

  15. Hadron production in the nucleus fragmentation region

    Energy Technology Data Exchange (ETDEWEB)

    Betemps, Marcos Andre [Universidade Federal de Pelotas, RS (Brazil). Conjunto Agrotecnico Visconde da Graca]. E-mail: marcos.betemps@ufpel.edu.br; Ducati, Maria Beatriz Gay [Universidade Federal de Pelotas, RS (Brazil)]. E-mail: beatriz.gay@ufrgs.br

    2008-09-15

    The RHIC hadron production data in hadronic collisions at the forward rapidities may hint the evidence of the Color Glass Condensate (CGC). However, in the opposite region, backward rapidities, new effects should be important in order to describe the observables. In this work, the charged hadron and {pi}{sup 0} productions are investigated in the fragmentation region of the nucleus (backward rapidities) considering dAu and pp collisions in the context of the Color Glass Condensate. In the backward rapidity region, only the proton can be treated as a CGC, and the large x nuclear effects need to be considered in order to describe the cross section. The results are shown by means of the nuclear modification ratio comparing the proton-nucleus and proton-proton cross sections and such ratio presents some dependences on the large x nuclear effects. (author)

  16. Single pion production in neutrino nucleus scattering

    CERN Document Server

    Hernández, E; Vacas, M J Vicente

    2013-01-01

    We study one pion production in both charged and neutral current neutrino nucleus scattering for neutrino energies below 2 GeV. We use a theoretical model for one pion production at the nucleon level that we correct for medium effects. The results are incorporated into a cascade program that apart from production also includes the pion final state interaction inside the nucleus. Besides, in some specific channels coherent pion production is also possible and we evaluate its contribution as well. Our results for total and differential cross sections are compared with recent data from the MiniBooNE Collaboration. The model provides an overall acceptable description of data, better for NC than for CC channels, although theory is systematically below data. Differential cross sections, folded with the full neutrino flux, show that most of the missing pions lie on the forward direction and at high energies.

  17. Protein quality control in the nucleus

    DEFF Research Database (Denmark)

    Nielsen, Sofie V.; Poulsen, Esben Guldahl; Rebula, Caio A.;

    2014-01-01

    to aggregate, cells have evolved several elaborate quality control systems to deal with these potentially toxic proteins. First, various molecular chaperones will seize the misfolded protein and either attempt to refold the protein or target it for degradation via the ubiquitin-proteasome system...... to be particularly active in protein quality control. Thus, specific ubiquitin-protein ligases located in the nucleus, target not only misfolded nuclear proteins, but also various misfolded cytosolic proteins which are transported to the nucleus prior to their degradation. In comparison, much less is known about...... these mechanisms in mammalian cells. Here we highlight recent advances in our understanding of nuclear protein quality control, in particular regarding substrate recognition and proteasomal degradation....

  18. Coherency in Neutrino-Nucleus Elastic Scattering

    CERN Document Server

    Kerman, S; Deniz, M; Wong, H T; Chen, J -W; Li, H B; Lin, S T; Liu, C -P; Yue, Q

    2016-01-01

    Neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. We report results of our quantitative studies on the transitions towards decoherency. A parameter ($\\alpha$) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold and target nucleus are studied. The ranges of $\\alpha$ which can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. Uncertainties in nuclear physics and in $\\alpha$ would constrain sensitivities in probing physics beyond the standard model. The maximum neutrino energies corresponding to $\\alpha$>0.95 are derived.

  19. Coherency in neutrino-nucleus elastic scattering

    Science.gov (United States)

    Kerman, S.; Sharma, V.; Deniz, M.; Wong, H. T.; Chen, J.-W.; Li, H. B.; Lin, S. T.; Liu, C.-P.; Yue, Q.; Texono Collaboration

    2016-06-01

    Neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. We report results of our quantitative studies on the transitions towards decoherency. A parameter (α ) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold, and target nucleus are studied. The ranges of α that can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. Uncertainties in nuclear physics and in α would constrain sensitivities in probing physics beyond the standard model. The maximum neutrino energies corresponding to α >0.95 are derived.

  20. Correlations in neutrino-nucleus scattering

    CERN Document Server

    Van Cuyck, Tom; Jachowicz, Natalie; González-Jiménez, Raul; Martini, Marco; Ryckebusch, Jan; Van Dessel, Nils

    2016-01-01

    We present a detailed study of charged-current quasielastic neutrino-nucleus scattering and of the influence of correlations on one- and two-nucleon knockout processes. The quasielastic neutrino-nucleus scattering cross sections, including the influence of long-range correlations, are evaluated within a continuum random phase approximation approach. The short-range correlation formalism is implemented in the impulse approximation by shifting the complexity induced by the correlations from the wave functions to the operators. The model is validated by confronting $(e,e^\\prime)$ cross-section predictions with electron scattering data in the kinematic region where the quasielastic channel is expected to dominate. Further, the $^{12}$C$(\

  1. Nickel-48, a very magic nucleus

    International Nuclear Information System (INIS)

    Ni48, which is doubly magic and very exotic, has been observed in an experiment performed at the GANIL accelerator. This nucleus, which is composed of 20 neutrons and 28 protons, is the most neutron-deficient nucleus that can be obtained, its decay mode has not yet been determined but theory predicts a 2-proton emission. Ni48 nuclei were obtained when accelerated (75 MeV/A) Ni58 ions had undergone fragmentation on natural nickel target. During this experiment 4 nuclei of Ni48 were produced as well as other very exotic nuclei: 90 nuclei of Ni49, 50 of Fe45 and 290 of Cr42. This experiment lasted 10 days and 1017 Ni58 ions were projected on the target. (A.C.)

  2. Hadron production in the nucleus fragmentation region

    International Nuclear Information System (INIS)

    The RHIC hadron production data in hadronic collisions at the forward rapidities may hint the evidence of the Color Glass Condensate (CGC). However, in the opposite region, backward rapidities, new effects should be important in order to describe the observables. In this work, the charged hadron and π0 productions are investigated in the fragmentation region of the nucleus (backward rapidities) considering dAu and pp collisions in the context of the Color Glass Condensate. In the backward rapidity region, only the proton can be treated as a CGC, and the large x nuclear effects need to be considered in order to describe the cross section. The results are shown by means of the nuclear modification ratio comparing the proton-nucleus and proton-proton cross sections and such ratio presents some dependences on the large x nuclear effects. (author)

  3. Nucleus spectroscopy: extreme masses and deformations

    International Nuclear Information System (INIS)

    The author proposes a synthesis of research activities performed since 1995 in the field of experimental nuclear physics, and more particularly in the investigation of two nucleus extreme states: deformation on the one hand, heavy and very heavy nuclei on the other hand. After a presentation of the context of investigations on deformation, rotation, and heavy nuclei, he gives an overview of developments regarding instruments (gamma spectrometers, detection of fission fragments, and detection at the focal plane of spectrometers or separators) and analysis techniques. Experiments and results are then reported and discussed, concerning super-deformed states with a high angular moment, spectroscopy of neutron-rich nuclei, very heavy nuclei close to nucleus map borders. He finally draws perspectives for middle and long term studies on the heaviest nuclei

  4. The fast Ice Nucleus chamber FINCH

    Science.gov (United States)

    Bundke, U.; Nillius, B.; Jaenicke, R.; Wetter, T.; Klein, H.; Bingemer, H.

    2008-11-01

    We present first results of our new developed Ice Nucleus (IN) counter FINCH from the sixth Cloud and Aerosol Characterization Experiment (CLACE 6) campaign at Jungfraujoch station, 3571 m asl. Measurements were made at the total and the ICE CVI inlet. Laboratory measurements of ice onset temperatures by FINCH are compared to those of the static diffusion chamber FRIDGE (FRankfurt Ice Deposition Freezing Experiment). Within the errors of both new instruments the results compare well to published data.

  5. Development of a Mobile Ice Nucleus Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70 deg C, and a single stage system can operate the warm wall at -45 deg C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  6. Revisiting the supratrigeminal nucleus in the rat.

    Science.gov (United States)

    Fujio, T; Sato, F; Tachibana, Y; Kato, T; Tomita, A; Higashiyama, K; Ono, T; Maeda, Y; Yoshida, A

    2016-06-01

    The supratrigeminal nucleus (Vsup), originally proposed as a premotoneuron pool in the trigeminal reflex arc, is a key structure of jaw movement control. Surprisingly, however, the location of the rat Vsup has not precisely been defined. In light of our previous cat studies, we made two hypotheses regarding the rat Vsup: (1) the Vsup is cytoarchitectonically distinguishable from its surrounding structures; (2) the Vsup receives central axon terminals of the trigeminal mesencephalic nucleus (Vmes) neurons which are primary afferents innervating muscle spindles of jaw-closing muscles and periodontal ligaments around the teeth. To test the first hypothesis, we examined the cytoarchitecture of the rat Vsup. The Vsup was identified as an area medially adjacent to the dorsomedial part of trigeminal principal sensory nucleus (Vp), and extended from the level just rostral to the caudal two-thirds of the trigeminal motor nucleus (Vmo) to the level approximately 150μm caudal to the Vmo. Our rat Vsup was much smaller and its location was considerably different in comparison to the Vsup reported previously. To evaluate the second hypothesis, we tested the distribution patterns of Vmes primary afferent terminals in the cytoarchitectonically identified Vsup. After transganglionic tracer applications to the masseter, deep temporal, and medial pterygoid nerves, a large number of axon terminals were observed in all parts of Vsup (especially in its medial part). After applications to the inferior alveolar, infraorbital, and lingual nerves, a small number of axon terminals were labeled in the caudolateral Vsup. The Vsup could also be identified electrophysiologically. After electrical stimulation of the masseter nerve, evoked potentials with slow negative component were isolated only in the Vsup. The present findings suggest that the rat Vsup can be cytoarchitectonically and electrophysiologically identified, receives somatotopic termination of the trigeminal primary afferents, and

  7. Neutrino-nucleus CCQE-like scattering

    CERN Document Server

    Nieves, J; Simo, I Ruiz; Sanchez, F; Vacas, M J Vicente

    2014-01-01

    RPA correlations, spectral function and 2p2h (multi-nucleon) effects on charged-current neutrino-nucleus reactions without emitted pions are discussed. We pay attention to the influence of RPA and multi-nucleon mechanisms on the MiniBooNE and MINERvA flux folded differential cross sections, the MiniBooNE flux unfolded total cross section and the neutrino energy reconstruction.

  8. Radiative corrections to pion-nucleus bremsstrahlung

    OpenAIRE

    Kaiser, N.(Physik Department T39, Technische Universität München, Garching, D-85747, Germany); Friedrich, J. M.

    2008-01-01

    We calculate the one-photon loop radiative corrections to virtual pion Compton scattering $\\pi^- \\gamma^* \\to \\pi^- \\gamma$, that subprocess which determines in the one-photon exchange approximation the pion-nucleus bremsstrahlung reaction $\\pi^- Z\\to \\pi^- Z \\gamma$. Ultraviolet and infrared divergencies of the loop integrals are both treated by dimensional regularization. Analytical expressions for the ${\\cal O}(\\alpha)$ corrections to the virtual Compton scattering amplitudes, $A(s,u,Q)$ a...

  9. Theoretical highlights of neutrino-nucleus interactions

    CERN Document Server

    Alvarez-Ruso, Luis

    2009-01-01

    The recent theoretical developments in the field of neutrino-nucleus interactions in the few-GeV region are reviewed based on the presentations made at the NuInt09 Workshop. The topics of electron scattering and its connections with neutrino interactions, neutrino induced quasielastic scattering and pion production (coherent and incoherent) are covered, with special emphasis on the challenges that arise in the comparison with new experimental data.

  10. Development of the sexually dimorphic nucleus of the preoptic area and the influence of estrogen-like compounds*****

    Institute of Scientific and Technical Information of China (English)

    Zhen He; Sherry Ann Ferguson; Li Cui; Lazar John Greenfield; Merle Gale Paule

    2013-01-01

    One of the wel -defined sexual y dimorphic structures in the brain is the sexual y dimorphic nucleus, a cluster of cells located in the preoptic area of the hypothalamus. The rodent sexual y dimorphic nucleus of the preoptic area can be delineated histological y using conventional Nissl staining or immunohistochemical y using calbindin D28K immunoreactivity. There is increasing use of the bindin D28K-delineated neural cluster to define the sexual y dimorphic nucleus of the preoptic area in rodents. Several mechanisms are proposed to underlie the processes that contribute to the sexual dimorphism (size difference) of the sexual y dimorphic nucleus of the preoptic area. Recent evidence indicates that stem cellactivity, including proliferation and migration presumably from the 3rd ventricle stem cellniche, may play a critical role in the postnatal development of the sexual y dimorphic nucleus of the preoptic area and its distinguishing sexual y dimorphic feature: a signifi-cantly larger volume in males. Sex hormones and estrogen-like compounds can affect the size of the sexual y dimorphic nucleus of the preoptic area. Despite considerable research, it remains un-clear whether estrogen-like compounds and/or sex hormones increase size of the sexual y dimor-phic nucleus of the preoptic area via an increase in stem cellactivity originating from the 3rd ventricle stem cellniche.

  11. Efficient nucleus detector in histopathology images.

    Science.gov (United States)

    Vink, J P; Van Leeuwen, M B; Van Deurzen, C H M; De Haan, G

    2013-02-01

    In traditional cancer diagnosis, (histo)pathological images of biopsy samples are visually analysed by pathologists. However, this judgment is subjective and leads to variability among pathologists. Digital scanners may enable automated objective assessment, improved quality and reduced throughput time. Nucleus detection is seen as the corner stone for a range of applications in automated assessment of (histo)pathological images. In this paper, we propose an efficient nucleus detector designed with machine learning. We applied colour deconvolution to reconstruct each applied stain. Next, we constructed a large feature set and modified AdaBoost to create two detectors, focused on different characteristics in appearance of nuclei. The proposed modification of AdaBoost enables inclusion of the computational cost of each feature during selection, thus improving the computational efficiency of the resulting detectors. The outputs of the two detectors are merged by a globally optimal active contour algorithm to refine the border of the detected nuclei. With a detection rate of 95% (on average 58 incorrectly found objects per field-of-view) based on 51 field-of-view images of Her2 immunohistochemistry stained breast tissue and a complete analysis in 1 s per field-of-view, our nucleus detector shows good performance and could enable a range of applications in automated assessment of (histo)pathological images. PMID:23252774

  12. The nucleus basalis in Huntington's disease.

    Science.gov (United States)

    Clark, A W; Parhad, I M; Folstein, S E; Whitehouse, P J; Hedreen, J C; Price, D L; Chase, G A

    1983-10-01

    The nucleus basalis of Meynert (nbM) provides most of the cholinergic input to the cerebral cortex. The loss of cortical choline acetyltransferase (CAT) activity in Alzheimer's disease (AD) and senile dementia of the Alzheimer's type (SDAT) appears to be related to a severe depopulation of the nbM in this dementia. In Huntington's disease (HD), by contrast, there is no loss of cortical CAT activity. The present quantitative study indicates that (1) there is no significant loss of neurons from the nbM in HD, and (2) that the previously described cytologic changes in the neurons of this nucleus in HD patients do not differ significantly from controls. These findings are consistent with the working hypothesis that the types of dementia associated with reductions of neocortical CAT activity are characterized by dysfunction or death of neurons in the nbM, but dementing disorders with normal neocortical CAT activity manifest no major abnormalities in this cholinergic nucleus of the basal forebrain. PMID:6225032

  13. Actomyosin contractility rotates the cell nucleus

    CERN Document Server

    Kumar, Abhishek; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G V

    2013-01-01

    The nucleus of the eukaryotic cell functions amidst active cytoskeletal filaments, but its response to the stresses carried by these filaments is largely unexplored. We report here the results of studies of the translational and rotational dynamics of the nuclei of single fibroblast cells, with the effects of cell migration suppressed by plating onto fibronectin-coated micro-fabricated patterns. Patterns of the same area but different shapes and/or aspect ratio were used to study the effect of cell geometry on the dynamics. On circles, squares and equilateral triangles, the nucleus undergoes persistent rotational motion, while on high-aspect-ratio rectangles of the same area it moves only back and forth. The circle and the triangle showed respectively the largest and the smallest angular speed. We show that our observations can be understood through a hydrodynamic approach in which the nucleus is treated as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active...

  14. Medium effect in high-density nuclear matter probed by systematic analyses of nucleus-nucleus elastic scattering

    CERN Document Server

    Furumoto, T; Yamamoto, Y

    2016-01-01

    We investigate the property of the high-density nuclear matter probed by the nucleus-nucleus elastic scattering in the framework of the double-folding (DF) model with the complex $G$-matrix interaction. The medium effect including three-body-force (TBF) effect is investigated with present two methods based on the frozen density approximation. With the both methods, the medium effect in the high density region is clearly seen on the potential and the elastic cross section of the $^{16}$O + $^{16}$O system at $E/A =$ 70 MeV. The crucial role of the medium effect for the high-density nuclear matter is also confirmed with other effective nucleon-nucleon ($NN$) interactions. In addition, present methods are applied to other heavy-ion elastic scattering systems. Again, the medium effect in the high-density region is clearly seen in the heavy-ion elastic cross section. The effect on the elastic cross section becomes invisible with the increase of the target mass and the incident energy within existing the experiment...

  15. Low P sub T hadron-nucleus interactions

    Science.gov (United States)

    Holynski, R.; Wozniak, K.

    1985-01-01

    The possibility of describing hadron-nucleus (hA) interactions is discussed in terms of a number of independent collisions of the projectile inside the target nucleus. This multiple rescattering may occur on a particle or quark parton level. To investigate the characteristics of hA interactions as a function of antineutrinos advantage is taken of the correlation between the average number antineutrinos of collisions of the projectile inside the nucleus and the number Ng of fast protons ejected from the struck nucleus. The relation antineutrinos vs Ng obtained in antineutrinos was used. For a given target nucleus this allows the selection of interactions occurring at different impact parameters.

  16. J/ψ production in proton-nucleus and nucleus-nucleus interactions at the CERN SPS

    International Nuclear Information System (INIS)

    The NA38 and NA50 experiments at the CERN SPS have measured charmonium production in different colliding systems with the aim of observing a phase transition from ordinary hadronic matter towards a state in which quarks and gluons are deconfined (Quark Gluon Plasma, QGP). This experimental research is based on the prediction that the J/ψ yield should be suppressed in deconfined matter. The analysis of the data collected by the NA50 experiment with Pb-Pb collisions at 158 GeV/c per nucleon shows that the J/ψ is anomalously suppressed with respect to the pattern observed in proton-nucleus and light ion reactions. (orig.)

  17. Oscillations of moments in high-energy nucleus-nucleus collisions

    Institute of Scientific and Technical Information of China (English)

    杨红艳; 周代翠; 钱琬燕; 王晓荣

    2001-01-01

    The definitions of density function and moment of multiplicity distribution are introduced,and the method of moment analysis in e+ e- and proton-proton (pp) interactions is extended into nu-cleus-nucleus (AA) interactions. We analyze the data for relativistic nucleus-nucleus collisions and cal-culate the values of Hq for charged particle multiplicity distributions, by which we study systematically the dependences of Hq on incident energy, mass of colliding system, pseudorapidity interval, centrality and truncation of multiplicity. We compare the oscillation structures induced by e + e-, pp and AA inter-actions, and the comparison and analysis are carried out between experimental data and QCD predic-tion. The latest results are given in this paper.

  18. The involvement of nucleus accumbens dopamine in appetitive and aversive motivation.

    Science.gov (United States)

    Salamone, J D

    1994-04-18

    In recent years, considerable emphasis has been placed upon the putative role of nucleus accumbens dopamine systems in appetitive motivation and positive reinforcement. However, considerable evidence indicates that brain dopamine in general, and nucleus accumbens dopamine in particular, is involved in aspects of aversive motivation. Administration of dopamine antagonists or localized interference with nucleus accumbens dopamine systems has been shown to disrupt active avoidance behavior. In addition, accumbens dopamine release and metabolism is activated by a wide variety of stressful conditions. A review of the literature indicates that there are substantial similarities between the characteristics of dopaminergic involvement in appetitive and aversive motivation. There is conflicting evidence about the role of dopamine in emotion, and little evidence to suggest that the profound and consistent changes in instrumental behavior produced by interference with DA systems are due to direct dopaminergic mediation of positive affective responses such as hedonia. It is suggested that nucleus accumbens dopamine is involved in aspects of sensorimotor functions that are involved in both appetitive and aversive motivation. PMID:8037860

  19. Distributive characteristics of projection from vestibular nuclei to nucleus raphe magnus in rats

    Institute of Scientific and Technical Information of China (English)

    Jingyu Sun; Yulin Dong; Fuxing Zhang; Jianhua Qiu; Yunqing Li

    2007-01-01

    excluded due to the deviation of injected site, and the other 9 were involved in the final analysis of results. The concentrated region of TMR injection wasmainly restricted to nucleus raphes magnus, and diffused to the surrounding area to different extents. There were obvious differences in the distributions of the labeled neurons among the subdivisions in vestibular nuclei, as well as the distributions of the labeled neurons at different sites in the same subdivision. The majority of the labeled neurons distributed in the rostral levels of medial vestibular nucleus and the lateral vestibular nucleus, while fewer labeled neurons were observed in superior vestibular nucleus. CONCLUSION: ①There might be bi-directional association between vestibular nucli and nucleus raphe magnus, suggesting that nucleus raphe magnus played a role in the transmission and processing of vestibular information.②The projection from nucleus raphe magnus to vestibular nucleus has certain distributive characteristics in the region.

  20. Study on chemical equilibrium in nucleus-nucleus collisions at relativistic energies

    CERN Document Server

    Manninen, J; Keränen, A; Gazdzicki, M; Stock, R; Manninen, Jaakko; Becattini, Francesco; Keranen, Antti; Gazdzicki, Marek; Stock, Reinhard

    2004-01-01

    We present a detailed study of chemical freeze-out in nucleus-nucleus collisions at beam energies of 11.6, 30, 40, 80 and 158A GeV. By analyzing hadronic multiplicities within the statistical hadronization approach, we have studied the chemical equilibration of the system as a function of center of mass energy and of the parameters of the source. Additionally, we have tested and compared different versions of the statistical model, with special emphasis on possible explanations of the observed strangeness hadronic phase space under-saturation.

  1. The effect of the relative nuclear size on the nucleus-nucleus interactions

    Science.gov (United States)

    Erofeeva, I. N.; Murzin, V. S.; Sivoklokov, S. Y.; Smirnova, L. N.

    1985-01-01

    The experimental data on the interactions of light nuclei (d, He(4), C(12)) at the momentum 4.2 GeV/cA with the carbon nuclei were taken in the 2-m propane bubble chamber. The distributions in the number of interacting nucleons, the spectra of protons, the mean energies of secondary pions and protons, the mean fractions of energy transferred to the pion and nucleon components are presented. The results of the investigation of the mechanism of nucleus-nucleus interactions can be used to calculate the nuclear cascades in the atmosphere.

  2. Nucleus-nucleus potential, energy dissipation and mass dispersion in fusion and transfer reactions

    CERN Document Server

    Washiyama, Kouhei; Ayik, Sakir

    2009-01-01

    The nucleus-nucleus potential and energy dissipation in fusion reactions are obtained from microscopic mean-field dynamics. The deduced potentials nicely reproduce the one extracted from experimental data. Energy dissipation shows a universal behaviour between different reactions. Also, the dispersion of mass distribution in transfer reaction is investigated in a stochastic mean-field dynamics. By including initial fluctuations in collective space, the description of the dispersion is much improved compared to that of mean field only. The result is consistent with the macroscopic phenomenological analysis of the experimental data.

  3. Aspects of Coulomb dissociation and interference in peripheral nucleus-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Nystrand, Joakim; Baltz, Anthony; Klein, Spencer R.

    2001-10-21

    Coherent vector meson production in peripheral nucleus-nucleus collisions is discussed. These interactions may occur for impact parameters much larger than the sum of the nuclear radii. Since the vector meson production is always localized to one of the nuclei, the system acts as a two-source interferometer in the transverse plane. By tagging the outgoing nuclei for Coulomb dissociation it is possible to obtain a measure of the impact parameter and thus the source separation in the interferometer. This is of particular interest since the life-time of the vector mesons are generally much shorter than the impact parameters of the collisions.

  4. Azimuthal correlations of hadrons and fragments in nucleus-nucleus collisions

    Institute of Scientific and Technical Information of China (English)

    LI Hui-Ling

    2011-01-01

    Two-particle (two-fragment) azimuthal correlation functions are studied by using a simple formula which describes uniformly azimuthal distributions of final-state charged particles and nuclear fragments.This formula is obtained in the framework of a multi-source thermal model (or multi-source ideal gas model).The calculated results are compared and found to be in agreement with the experimental data of charged hadrons and nuclear fragments in nucleus-nucleus collisions at intermediate and high energies.

  5. High energy nucleus--nucleus studies at the Berkeley Bevalac. [Survey

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, L.S.

    1976-09-01

    A survey of high-energy nucleus--nucleus experiments performed at the Berkeley Bevalac Facility is presented. Experimental results are divided into the general areas of peripheral and central collisions. Results on projectile and target fragmentation, total cross-section measurements, pion and photon production, and charged-particle multiplicities are stressed. Recently, there have been theoretical predictions concerning the possibility of observing new phenomena such as shock waves, pion condensates, or collapsed nuclear matter. Existing data relevant to some of these speculations are discussed. A brief discussion of future developments with high-energy nuclear beams is also presented. 27 figures, 1 table.

  6. Morphometric characteristics of Neuropeptide Y immunoreactive neurons of human cortical amygdaloid nucleus

    Directory of Open Access Journals (Sweden)

    Mališ Miloš

    2008-01-01

    Full Text Available Introduction Cortical amygdaloid nucleus belongs to the corticomedial part of the amygdaloid complex. In this nucleus there are neurons that produce neuropetide Y. This peptide has important roles in sleeping, learning, memory, gastrointestinal regulation, anxiety, epilepsy, alcoholism and depression. Material and methods We investigated morphometric characteristics (numbers of primary dendrites, longer and shorter diameters of cell bodies and maximal radius of dendritic arborization of NPY immunoreactive neurons of human cortical amygdaloid nucleus on 6 male adult human brains, aged 46 to 77 years, by immunohistochemical avidin-biotin technique. Results Our investigation has shown that in this nucleus there is a moderate number of NPY immunoreactive neurons. 67% of found neurons were nonpyramidal, while 33% were pyramidal. Among the nonpyramidal neurons the dominant groups were multipolar neurons (41% - of which 25% were multipolar irregular, and 16% multipolar oval. Among the pyramidal neurons the dominant groups were the neurons with triangular shape of cell body (21%. All found NPY immunoreactive neurons (pyramidal and nonpyramidal altogether had intervals of values of numbers of primary dendrites 2 to 6, longer diameters of cell bodies 13 to 38 µm, shorter diameters of cell bodies 9 to 20 µm and maximal radius of dendritic arborization 50 to 340 µm. More than a half of investigated neurons (57% had 3 primary dendrites. Discussion and conclusion The other researchers did not find such percentage of pyramidal immunoreactive neurons in this amygdaloid nucleus. If we compare our results with the results of the ather researchers we can conclude that all pyramidal NPY immunoreactive neurons found in this human amygdaloid nucleus belong to the class I of neurons, and that all nonpyramidal NPY immunoreactive neurons belong to the class II of neurons described by other researchers. We suppose that all found pyramidal neurons were projectional.

  7. Dopamine in the nucleus accumbens modulates the memory of social defeat in Syrian hamsters (Mesocricetus auratus).

    Science.gov (United States)

    Gray, C L; Norvelle, A; Larkin, T; Huhman, K L

    2015-06-01

    Conditioned defeat (CD) is a behavioral response that occurs in Syrian hamsters after they experience social defeat. Subsequently, defeated hamsters no longer produce territorial aggression but instead exhibit heightened levels of avoidance and submission, even when confronted with a smaller, non-aggressive intruder. Dopamine in the nucleus accumbens is hypothesized to act as a signal of salience for both rewarding and aversive stimuli to promote memory formation and appropriate behavioral responses to significant events. The purpose of the present study was to test the hypothesis that dopamine in the nucleus accumbens modulates the acquisition and expression of behavioral responses to social defeat. In Experiment 1, bilateral infusion of the non-specific D1/D2 receptor antagonist cis(z)flupenthixol (3.75 μg/150 nl saline) into the nucleus accumbens 5 min prior to defeat training significantly reduced submissive and defensive behavior expressed 24h later in response to a non-aggressive intruder. In Experiment 2, infusion of 3.75 μg cis-(Z)-flupenthixol 5 min before conditioned defeat testing with a non-aggressive intruder significantly increased aggressive behavior in drug-infused subjects. In Experiment 3, we found that the effect of cis-(Z)-flupenthixol on aggression was specific to defeated animals as infusion of drug into the nucleus accumbens of non-defeated animals did not significantly alter their behavior in response to a non-aggressive intruder. These data demonstrate that dopamine in the nucleus accumbens modulates both acquisition and expression of social stress-induced behavioral changes and suggest that the nucleus accumbens plays an important role in the suppression of aggression that is observed after social defeat. PMID:25721736

  8. Contemporary models of the atomic nucleus

    CERN Document Server

    Nemirovskii, P E

    2013-01-01

    Contemporary Models of the Atomic Nucleus discusses nuclear structure and properties, expounding contemporary theoretical concepts of the low-energy nuclear processes underlying in nuclear models. This book focuses on subjects such as the optical nuclear model, unified or collective model, and deuteron stripping reaction. Other topics discussed include the basic nuclear properties; shell model; theoretical analysis of the shell model; and radiative transitions and alpha-decay. The deuteron theory and the liquid drop nuclear model with its application to fission theory are also mentioned, but o

  9. Dust activity of Comet Halley's nucleus

    Science.gov (United States)

    Keller, H. U.; Delamere, W. A.; Huebner, W. F.; Reitsema, H.; Schmidt, H. U.; Schmidt, W. K. H.; Whipple, Fred L.; Wilhelm, K.

    1986-01-01

    Images obtained by the Halley multicolor camera using the clear filter with a pass band from 300 to 1000 nm were used to study dust activity in the comet nucleus. Comparisons with ground based observations confirm that dust production towards the Sun increases in activity relative to the southern background source while the Giotto spacecraft was approaching. This is in agreement with the assumption that the sunward activity becomes stronger when the source rotates towards the Sun. Estimated dust column density is 90 billion/sqm, with optical thickness less than or = 0.3. Surface reflectivity is less than 1%, indicating a very rough surface with large fractions of shadowed areas.

  10. Unveiling the nucleus of NGC 7172

    Science.gov (United States)

    Smajić, S.; Fischer, S.; Zuther, J.; Eckart, A.

    2012-08-01

    Aims: We present the results of near-infrared (NIR) H + K European Southern Observatory SINFONI integral field spectroscopy (IFS) of the Seyfert 2 galaxy NGC 7172. We investigate the central 800 pc, concentrating on excitation conditions, morphology, and stellar content. NGC 7172 was selected from a sample of the ten nearest Seyfert 2 galaxies from the Veron-Cetty & Veron catalogue. All objects were chosen as test cases for adaptive optics (AO) assisted observations that allow a detailed study (at high spatial and spectral resolution) of the nuclear and host environments. NGC 7172 has a prominent dustlane crossing the central galaxy region from east to west, which makes it an ideal candidate to investigate the effect of obscuration by strong galactic extinction on (active) galaxies and their classification. Methods: The NIR is less influenced by dust extinction than optical light and is sensitive to the mass-dominating stellar populations. SINFONI integral field spectroscopy combines NIR imaging and spectroscopy and provides us with the opportunity to analyze several emission and absorption lines to investigate the stellar populations and ionization mechanisms over the 4″ × 4″ field of view (FOV). Results: We present emission and absorption line measurements in the central 800 pc of NGC 7172. The detection of [Si vi] and broad Paα and Brγ components are clear signs of an accreting super-massive black hole hiding behind the prominent dustlane at visible wavelengths. Hot temperatures of about 1300 K are indicative of a dusty torus in the nuclear region. Narrow components of Paα and Brγ enable us to make an extinction measurement. Our measures of the molecular hydrogen lines, hydrogen recombination lines, and [Fe ii] indicate that the excitation of these lines is caused by an active galactic nucleus. The central region of the galactic disk is predominantly inhabited by gas, dust, and an old K-M type giant stellar population. The gaseous, molecular, and

  11. A thalamic input to the nucleus accumbens mediates opiate dependence.

    Science.gov (United States)

    Zhu, Yingjie; Wienecke, Carl F R; Nachtrab, Gregory; Chen, Xiaoke

    2016-02-11

    Chronic opiate use induces opiate dependence, which is characterized by extremely unpleasant physical and emotional feelings after drug use is terminated. Both the rewarding effects of a drug and the desire to avoid withdrawal symptoms motivate continued drug use, and the nucleus accumbens is important for orchestrating both processes. While multiple inputs to the nucleus accumbens regulate reward, little is known about the nucleus accumbens circuitry underlying withdrawal. Here we identify the paraventricular nucleus of the thalamus as a prominent input to the nucleus accumbens mediating the expression of opiate-withdrawal-induced physical signs and aversive memory. Activity in the paraventricular nucleus of the thalamus to nucleus accumbens pathway is necessary and sufficient to mediate behavioural aversion. Selectively silencing this pathway abolishes aversive symptoms in two different mouse models of opiate withdrawal. Chronic morphine exposure selectively potentiates excitatory transmission between the paraventricular nucleus of the thalamus and D2-receptor-expressing medium spiny neurons via synaptic insertion of GluA2-lacking AMPA receptors. Notably, in vivo optogenetic depotentiation restores normal transmission at these synapses and robustly suppresses morphine withdrawal symptoms. This links morphine-evoked pathway- and cell-type-specific plasticity in the paraventricular nucleus of the thalamus to nucleus accumbens circuit to opiate dependence, and suggests that reprogramming this circuit holds promise for treating opiate addiction.

  12. Experimental study of collective flow phenomena in high-energy nucleus-nucleus collisions

    CERN Document Server

    Chkhaidze, L V; Kharkhelauri, L L

    2002-01-01

    The results of the experimental study of collective flow phenomena, such as the sideward and elliptic flow of nuclear matter, discovered during the last 10-15 years in high-energy nucleus-nucleus collisions are presented in this review. Sideward (often termed directed) and elliptic flows have been observed for protons, antiprotons, light nuclei, pions, kaons, and lambdas emitted in nucleus-nucleus collisions at 0.1-1.8 GeV/nucleon of LBL Bevalac and GSI/SIS by Plastic-Ball, Streamer Chamber, EOS-NPC, FOPI, LAND, TAPS, and KAOS collaborations; at 2-4 GeV/nucleon of Dubna JINR by SKM-200-GIBS, Propane Buble Chamber, and Emulsion Chamber collaborations; at 2-14 GeV/nucleon of BNL AGS, by the E877, E895, and E917 collaborations; and at 60 and 200 GeV/nucleon of CERN SPS, by the WA98 and NA49 collaborations and more recently by the STAR at RHIC BNL. In the review, the results of the SKM-200-GIBS collaboration of JINR are presented and compared with the results of different experiments by Bevalac, GSI/SIS, BNL, and...

  13. Thermal Bremsstrahlung probing nuclear multifragmentation in nucleus-nucleus collisions around the Fermi energy

    International Nuclear Information System (INIS)

    The thermodynamical properties of nuclear matter at moderate temperatures and densities, in the vicinity of the predicted nuclear liquid-gas phase transition, are studied using as experimental probe the hard-photons (Eγ > 30 MeV) emitted in nucleus-nucleus collisions. Photon and charged-particle production in four different heavy-ion reactions (Ar36 + Au197, Ag107, Ni58, C12 at 60 A*MeV) is measured exclusively and inclusively coupling the TAPS photon spectrometer with two charged-particle and intermediate-mass-fragment detectors covering nearly 4π. We confirm that Bremsstrahlung emission in first-chance (off-equilibrium) proton-neutron collisions (pnγ) is the dominant origin of hard photons. We also firmly establish the existence of a thermal radiation component emitted in second-chance proton-neutron collisions. This thermal Bremsstrahlung emission takes place in semi-central and central nucleus-nucleus reactions involving heavy targets. We exploit this observation i) to demonstrate that thermal equilibrium is reached during the reaction, ii) to establish a new thermometer of nuclear matter based on Bremsstrahlung photons, iii) to derive the thermodynamical properties of the excited nuclear sources and, in particular, to establish a 'caloric curve' (temperature versus excitation energy), and iv) to assess the time-scales of the nuclear break-up process. (author)

  14. Radiative corrections to pion-nucleus bremsstrahlung

    CERN Document Server

    Kaiser, N

    2008-01-01

    We calculate the one-photon loop radiative corrections to virtual pion Compton scattering $\\pi^- \\gamma^* \\to \\pi^- \\gamma$, that subprocess which determines in the one-photon exchange approximation the pion-nucleus bremsstrahlung reaction $\\pi^- Z\\to \\pi^- Z \\gamma$. Ultraviolet and infrared divergencies of the loop integrals are both treated by dimensional regularization. Analytical expressions for the ${\\cal O}(\\alpha)$ corrections to the virtual Compton scattering amplitudes, $A(s,u,Q)$ and $B(s,u,Q)$, are derived with their full dependence on the (small) photon virtuality $Q$ from 9 classes of contributing one-loop diagrams. Infrared finiteness of these virtual radiative corrections is achieved (in the standard way) by including soft photon radiation below an energy cut-off $\\lambda$. In the region of low $\\pi^- \\gamma$ center-of-mass energies, where the pion-nucleus bremsstrahlung process is used to extract the pion electric and magnetic polarizabilities, we find radiative corrections up to about -3% fo...

  15. Deep brain stimulation of the subthalamic nucleus modulates sensitivity to decision outcome value in Parkinson's disease.

    Science.gov (United States)

    Seymour, Ben; Barbe, Michael; Dayan, Peter; Shiner, Tamara; Dolan, Ray; Fink, Gereon R

    2016-01-01

    Deep brain stimulation (DBS) of the subthalamic nucleus in Parkinson's disease is known to cause a subtle but important adverse impact on behaviour, with impulsivity its most widely reported manifestation. However, precisely which computational components of the decision process are modulated is not fully understood. Here we probe a number of distinct subprocesses, including temporal discount, outcome utility, instrumental learning rate, instrumental outcome sensitivity, reward-loss trade-offs, and perseveration. We tested 22 Parkinson's Disease patients both on and off subthalamic nucleus deep brain stimulation (STN-DBS), while they performed an instrumental learning task involving financial rewards and losses, and an inter-temporal choice task for financial rewards. We found that instrumental learning performance was significantly worse following stimulation, due to modulation of instrumental outcome sensitivity. Specifically, patients became less sensitive to decision values for both rewards and losses, but without any change to the learning rate or reward-loss trade-offs. However, we found no evidence that DBS modulated different components of temporal impulsivity. In conclusion, our results implicate the subthalamic nucleus in a modulation of outcome value in experience-based learning and decision-making in Parkinson's disease, suggesting a more pervasive role of the subthalamic nucleus in the control of human decision-making than previously thought. PMID:27624437

  16. DNA damage-induced translocation of S100A11 into the nucleus regulates cell proliferation

    Directory of Open Access Journals (Sweden)

    Ulbricht Tobias

    2010-12-01

    Full Text Available Abstract Background Proteins are able to react in response to distinct stress stimuli by alteration of their subcellular distribution. The stress-responsive protein S100A11 belongs to the family of multifunctional S100 proteins which have been implicated in several key biological processes. Previously, we have shown that S100A11 is directly involved in DNA repair processes at damaged chromatin in the nucleus. To gain further insight into the underlying mechanism subcellular trafficking of S100A11 in response to DNA damage was analyzed. Results We show that DNA damage induces a nucleolin-mediated translocation of S100A11 from the cytoplasm into the nucleus. This translocation is impeded by inhibition of the phosphorylation activity of PKCα. Translocation of S100A11 into the nucleus correlates with an increased cellular p21 protein level. Depletion of nucleolin by siRNA severely impairs translocation of S100A11 into the nucleus resulting in a decreased p21 protein level. Additionally, cells lacking nucleolin showed a reduced colony forming capacity. Conclusions These observations suggest that regulation of the subcellular distribution of S100A11 plays an important role in the DNA damage response and p21-mediated cell cycle control.

  17. The Nucleus Accumbens: Mechanisms of Addiction across Drug Classes Reflect the Importance of Glutamate Homeostasis.

    Science.gov (United States)

    Scofield, M D; Heinsbroek, J A; Gipson, C D; Kupchik, Y M; Spencer, S; Smith, A C W; Roberts-Wolfe, D; Kalivas, P W

    2016-07-01

    The nucleus accumbens is a major input structure of the basal ganglia and integrates information from cortical and limbic structures to mediate goal-directed behaviors. Chronic exposure to several classes of drugs of abuse disrupts plasticity in this region, allowing drug-associated cues to engender a pathologic motivation for drug seeking. A number of alterations in glutamatergic transmission occur within the nucleus accumbens after withdrawal from chronic drug exposure. These drug-induced neuroadaptations serve as the molecular basis for relapse vulnerability. In this review, we focus on the role that glutamate signal transduction in the nucleus accumbens plays in addiction-related behaviors. First, we explore the nucleus accumbens, including the cell types and neuronal populations present as well as afferent and efferent connections. Next we discuss rodent models of addiction and assess the viability of these models for testing candidate pharmacotherapies for the prevention of relapse. Then we provide a review of the literature describing how synaptic plasticity in the accumbens is altered after exposure to drugs of abuse and withdrawal and also how pharmacological manipulation of glutamate systems in the accumbens can inhibit drug seeking in the laboratory setting. Finally, we examine results from clinical trials in which pharmacotherapies designed to manipulate glutamate systems have been effective in treating relapse in human patients. Further elucidation of how drugs of abuse alter glutamatergic plasticity within the accumbens will be necessary for the development of new therapeutics for the treatment of addiction across all classes of addictive substances. PMID:27363441

  18. Glucocorticoid receptors in the nucleus of the solitary tract (NTS) decrease endocrine and behavioral stress responses

    OpenAIRE

    Ghosal, Sriparna; Bundzikova-Osacka, Jana; Dolgas, C. Mark; Myers, Brent; Herman, James P.

    2014-01-01

    Stress activates the hypothalamo-pituitary-adrenal (HPA) axis, leading to adrenocortical secretion of glucocorticoids. The magnitude and duration of the HPA axis response is mediated in large part by the glucocorticoid receptor (GR). The nucleus of the solitary tract (NTS) abundantly expresses the GR and is a key brain region for processing autonomic and endocrine stress responses. This study tests the hypothesis that GR within the NTS plays an important role in inhibiting stress-induced endo...

  19. Hydrogen sulfide augments synaptic neurotransmission in the nucleus of the solitary tract

    OpenAIRE

    Austgen, James R.; Hermann, Gerlinda E.; Dantzler, Heather A.; Richard C Rogers; Kline, David D.

    2011-01-01

    Within the brain stem, the nucleus tractus solitarii (NTS) serves as a principal central site for sensory afferent integration from the cardiovascular and respiratory reflexes. Neuronal activity and synaptic transmission in the NTS are highly pliable and subject to neuromodulation. In the central nervous system, hydrogen sulfide (H2S) is a gasotransmitter generated primarily by the enzyme cystathionine-β-synthase (CBS). We sought to determine the role of H2S, and its generation by CBS, in NTS...

  20. Feline Immunodeficiency Virus as a Gene Transfer Vector in the Rat Nucleus Tractus Solitarii

    OpenAIRE

    Lin, L. H.; Langasek, J. E.; Talman, L. S.; Taktakishvili, O. M.; Talman, W. T.

    2009-01-01

    Gene transfer has been used to examine the role of putative neurotransmitters in the nucleus tractus solitarii (NTS). Most such studies used adenovirus vector-mediated gene transfer although adenovirus vector transfects both neuronal and non-neuronal cells. Successful transfection in the NTS has also been reported with lentivirus as the vector. Feline immunodeficiency virus (FIV), a lentivirus, may preferentially transfect neurons and could be a powerful tool to delineate physiological effect...

  1. Endogenous Brain Derived Neurotrophic Factor in the Nucleus Tractus Solitarius Tonically Regulates Synaptic and Autonomic Function

    OpenAIRE

    Clark, Catharine G.; Hasser, Eileen M.; Kunze, Diana L.; Katz, David M.; Kline, David D.

    2011-01-01

    Brain derived neurotrophic factor (BDNF) and its receptor, TrkB, are highly expressed in the nucleus tractus solitarius (nTS), the principal target of cardiovascular primary afferent input to the brainstem. However, little is known about the role of BDNF signaling in nTS in cardiovascular homeostasis. We examined whether BDNF in nTS modulates cardiovascular function in vivo and regulates synaptic and/or neuronal activity in isolated brainstem slices. Microinjection of BDNF into the rat medial...

  2. Adiponectin Depolarizes Parvocellular Paraventricular Nucleus Neurons Controlling Neuroendocrine and Autonomic Function

    OpenAIRE

    Hoyda, Ted Donald; Samson, Willis Kendrick; Ferguson, Alastair Victor

    2008-01-01

    Adiponectin plays important roles in the control of energy homeostasis and autonomic function through peripheral and central nervous system actions. The paraventricular nucleus (PVN) of the hypothalamus is a primary site of neuroendocrine (NE) and autonomic integration, and, thus, a potential target for adiponectin actions. Here, we investigate actions of adiponectin on parvocellular PVN neurons. Adiponectin influenced the majority (65%) of parvocellular PVN neurons, depolarizing 47%, whereas...

  3. Reward-dependent modulation of neuronal activity in the primate dorsal raphe nucleus

    OpenAIRE

    NAKAMURA, KAE; Matsumoto, Masayuki; Hikosaka, Okihide

    2008-01-01

    The dopamine system has been thought to play a central role in guiding behavior based on rewards. Recent pharmacological studies suggest that another monoamine neurotransmitter, serotonin, is also involved in reward processing. To elucidate the functional relationship between serotonin neurons and dopamine neurons, we performed single unit recording in the dorsal raphe nucleus (DRN), a major source of serotonin, and the substantia nigra pars compacta, a major source of dopamine, while monkeys...

  4. Biological substrates of reward and aversion: a nucleus accumbens activity hypothesis

    OpenAIRE

    Carlezon, William A; Thomas, Mark J.

    2008-01-01

    The nucleus accumbens (NAc) is a critical element of the mesocorticolimbic system, a brain circuit implicated in reward and motivation. This basal forebrain structure receives dopamine (DA) input from the ventral tegmental area (VTA) and glutamate (GLU) input from regions including the prefrontal cortex (PFC), amygdala (AMG), and hippocampus (HIP). As such, it integrates inputs from limbic and cortical regions, linking motivation with action. The NAc has a well-established role in mediating t...

  5. Norepinephrine and Serotonin Receptors in the Paraventricular Nucleus Interactively Modulate Ethanol Consumption

    OpenAIRE

    Hodge, Clyde W.; Slawecki, Craig J.; Aiken, Amy S.

    1996-01-01

    The homeostatic function of the hypothalamus has long been recognized. In particular, the role of the paraventricular nucleus (PVN) in regulating ingestive behavior has been of interest. Infusions of serotonin and norepinephrine Into the PVN are correlated with nutrient selective decreases and increases in consumatory behavior, respectively. Given the wide range of homeostatic functions of the hypothalamus, it is plausible that similar hypothalamic mechanisms may also be involved in the regul...

  6. The Acute Effects of Leptin Require PI3K Signaling in the Hypothalamic Ventral Premammillary Nucleus

    OpenAIRE

    Williams, Kevin W; Sohn, Jong-Woo; Donato, Jose; Lee, Charlotte E.; Zhao, Jean J.; Elmquist, Joel K.; Elias, Carol F.

    2011-01-01

    Evidence suggests that the role played by the adipocyte-derived hormone leptin in female reproductive physiologyis mediated in part by neurons located within the ventral premammillary nucleus (PMV). Leptin activates PMV neurons; however, the intracellular signaling pathway and channel(s) involved remain undefined. Notably, leptin's excitatory and inhibitory effects within hypothalamic and brainstem nuclei share the intracellular signaling cascade phosphoinositide 3 kinase (PI3K). Therefore, w...

  7. Sleep Disorders in Parkinsonian Macaques: Effects of l-Dopa Treatment and Pedunculopontine Nucleus Lesion

    OpenAIRE

    Belaid, Hayat; Adrien, Joëlle; Laffrat, Elodie; Tandé, Dominique; Karachi, Carine; Grabli, David; Arnulf, Isabelle; Clark, Stewart D.; Drouot, Xavier; Hirsch, Etienne C.; François, Chantal

    2014-01-01

    Patients with Parkinson's disease (PD) display significant sleep disturbances and daytime sleepiness. Dopaminergic treatment dramatically improves PD motor symptoms, but its action on sleep remains controversial, suggesting a causal role of nondopaminergic lesions in these symptoms. Because the pedunculopontine nucleus (PPN) regulates sleep and arousal, and in view of the loss of its cholinergic neurons in PD, the PPN could be involved in these sleep disorders. The aims of this study were as ...

  8. Functional interactions between the nucleus tractus solitarius (NTS) and nucleus accumbens shell in modulating memory for arousing experiences.

    Science.gov (United States)

    Kerfoot, Erin C; Chattillion, Elizabeth A; Williams, Cedric L

    2008-01-01

    The shell division of the nucleus accumbens receives noradrenergic input from neurons in the nucleus of the solitary tract (NTS) that transmit information regarding fluctuations in peripheral hormonal and autonomic activity. Accumbens shell neurons also receive converging inputs from limbic areas such as the hippocampus and amygdala that process newly acquired information. However, few studies have explored whether peripheral information regarding changes in emotional arousal contributes to memory processing in the accumbens. The beneficial effects on memory produced by emotional arousal and the corresponding activation of NTS neurons may be mediated through influences on neuronal activity in the accumbens shell during memory encoding. To explore this putative relationship, Experiment 1 examined interactions between the NTS and the accumbens shell in modulating memory for responses acquired after footshock training in a water-motivated inhibitory avoidance task. Memory for the noxious shock was significantly improved by posttraining excitation of noradrenergic NTS neurons. The enhanced retention produced by activating NTS neurons was attenuated by suppressing neuronal activity in the accumbens shell with bupivacaine (0.25%/0.5 microl). Experiment 2 examined the direct involvement of accumbens shell noradrenergic activation in the modulation of memory for psychologically arousing events such as a reduction in perceived reward value. Noradrenergic activation of the accumbens shell with phenylephrine (1.0 microg/0.5 microl) produced an enhancement in memory for the frustrating experience relative to control injections as evidenced by runway performance on an extended seven-day retention test. These findings demonstrate a functional relationship between NTS neurons and the accumbens shell in modulating memory following physiological arousal and identifies a role of norepinephrine in modulating synaptic activity in the accumbens shell to facilitate this process.

  9. Analysis of Intermediate-Energy Nucleus-Nucleus Spallation, Fission, and Fragmentation Reactions with the LAQGSM code

    OpenAIRE

    Mashnik, S. G.; Gudima, K. K.; Prael, R. E.; Sierk, A. J.

    2003-01-01

    The LAQGSM code has been recently developed at Los Alamos National Laboratory to simulate nuclear reactions for proton radiography applications. We have benchmarked our code against most available measured data both for proton-nucleus and nucleus-nucleus interactions at incident energies from 10 MeV to 800 GeV and have compared our results with predictions of other current models used by the nuclear community. Here, we present a brief description of our code and show illustrative results obta...

  10. GABA in Paraventricular Nucleus Regulates Adipose Afferent Reflex in Rats.

    Directory of Open Access Journals (Sweden)

    Lei Ding

    Full Text Available Chemical stimulation of white adipose tissue (WAT induces adipose afferent reflex (AAR, and thereby causes a general sympathetic activation. Paraventricular nucleus (PVN is important in control of sympathetic outflow. This study was designed to investigate the role of γ-aminobutyric acid (GABA in PVN in regulating the AAR.Experiments were carried out in anesthetized rats. Renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were continuously recorded. AAR was evaluated by the RSNA and MAP responses to electrical stimulation of the right epididymal WAT (eWAT afferent nerve. Electrical stimulation of eWAT afferent nerve increase RSNA. Bilateral microinjection of the GABAA receptor agonist isoguvacine or the GABAB receptor agonist baclofen attenuated the AAR. The effect of isoguvacine on the AAR was greater than that of baclofen. The GABAA receptor antagonist gabazine enhanced the AAR, while the GABAB receptor antagonist CGP-35348 had no significant effect on the AAR. Bilateral PVN microinjection of vigabatrin, a selective GABA-transaminase inhibitor, to increase endogenous GABA levels in the PVN abolished the AAR. The inhibitory effect of vigabatrin on the AAR was attenuated by the pretreatment with gabazine or CGP-35348. Pretreatment with combined gabazine and CGP-35348 abolished the effects of vigabatrin.Activation of GABAA or GABAB receptors in the PVN inhibits the AAR. Blockade of GABAA receptors in the PVN enhances the AAR. Endogenous GABA in the PVN plays an important role in regulating the AAR.

  11. Laser-Nucleus Interactions: The Quasiadiabatic Regime

    CERN Document Server

    Pálffy, Adriana; Hoefer, Axel; Weidenmüller, Hans A

    2015-01-01

    The interaction between nuclei and a strong zeptosecond laser pulse with coherent MeV photons is investigated theoretically. We provide a first semi-quantitative study of the quasiadiabatic regime where the photon absorption rate is comparable to the nuclear equilibration rate. In that regime, multiple photon absorption leads to the formation of a compound nucleus in the so-far unexplored regime of excitation energies several hundred MeV above the yrast line. The temporal dynamics of the process is investigated by means of a set of master equations that account for dipole absorption, stimulated dipole emission, neutron decay and induced fission in a chain of nuclei. That set is solved numerically by means of state-of-the-art matrix exponential methods also used in nuclear fuel burnup and radioactivity transport calculations. Our quantitative estimates predict the excitation path and range of nuclei reached by neutron decay and provide relevant information for the layout of future experiments.

  12. Nature of multiple-nucleus cluster galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Merritt, D.

    1984-05-01

    In models for the evolution of galaxy clusters which include dynamical friction with the dark binding matter, the distribution of galaxies becomes more concentrated to the cluster center with time. In a cluster like Coma, this evolution could increase by a factor of approximately 3 the probability of finding a galaxy very close to the cluster center, without decreasing the typical velocity of such a galaxy significantly below the cluster mean. Such an enhancement is roughly what is needed to explain the large number of first-ranked cluster galaxies which are observed to have extra ''nuclei''; it is also consistent with the high velocities typically measured for these ''nuclei.'' Unlike the cannibalism model, this model predicts that the majority of multiple-nucleus systems are transient phenomena, and not galaxies in the process of merging.

  13. Suprachiasmatic Nucleus: Cell Autonomy and Network Properties

    Science.gov (United States)

    Welsh, David K.; Takahashi, Joseph S.; Kay, Steve A.

    2013-01-01

    The suprachiasmatic nucleus (SCN) is the primary circadian pacemaker in mammals. Individual SCN neurons in dispersed culture can generate independent circadian oscillations of clock gene expression and neuronal firing. However, SCN rhythmicity depends on sufficient membrane depolarization and levels of intracellular calcium and cAMP. In the intact SCN, cellular oscillations are synchronized and reinforced by rhythmic synaptic input from other cells, resulting in a reproducible topographic pattern of distinct phases and amplitudes specified by SCN circuit organization. The SCN network synchronizes its component cellular oscillators, reinforces their oscillations, responds to light input by altering their phase distribution, increases their robustness to genetic perturbations, and enhances their precision. Thus, even though individual SCN neurons can be cell-autonomous circadian oscillators, neuronal network properties are integral to normal function of the SCN. PMID:20148688

  14. Heavy flavors in nucleus-nucleus collisions at RHIC and LHC

    Directory of Open Access Journals (Sweden)

    Nardi Marzia

    2014-04-01

    Full Text Available A multi-step setup for heavy-flavor studies in high-energy nucleus-nucleus (AA collisions — addressing within a comprehensive framework the initial QQ¯$Q\\overline Q $ production, the propagation in the hot medium until decoupling and the final hadronization and decays — is presented. The propagation of the heavy quarks in the medium is described in a framework provided by the relativistic Langevin equation and the corresponding numerical results are compared to experimental data from RHIC and the LHC. In particular, outcomes for the nuclear modification factor RAA and for the elliptic flow υ2 of D/B mesons, heavy-flavor electrons and non-prompt J/ψ’s are displayed.

  15. Experimental and phenomenological investigations of QCD matter in high-energy nucleus-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Andronic, Anton

    2014-07-15

    This thesis is heterogeneous, comprising experimental papers at low energies (SIS-18 at GSI) and at the LHC, papers on phenomenology of high-energy nucleus-nucleus collisions, and papers on detectors. The overview covers the experimental papers and those on phenomenology. I have chosen to write it in a general manner, intended to be accessible to non-experts. It emphasizes recent measurements and their understanding at the LHC. The detector papers, which address many principle aspects of gaseous detectors, are summarized and placed in context in the review I co-wrote and which closes the stack. The detector papers included here are the outcome of an R and D program for the Transition Radiation Detector of ALICE.

  16. Forward-backward correlations in nucleus-nucleus collisions: baseline contributions from geometrical fluctuations

    CERN Document Server

    Konchakovski, V P; Torrieri, G; Gorenstein, M I; Bratkovskaya, E L

    2008-01-01

    We discuss the effects of initial collision geometry and centrality bin definition on correlation and fluctuation observables in nucleus-nucleus collisions. We focus on the forward-backward correlation coefficient recently measured by the STAR Collaboration in Au+Au collisions at RHIC. Our study is carried out within two models: the Glauber Monte Carlo code with a `toy' wounded nucleon model and the hadron-string dynamics (HSD) transport approach. We show that strong correlations can arise due to averaging over events in one centrality bin. We, furthermore, argue that a study of the dependence of correlations on the centrality bin definition as well as the bin size may distinguish between these `trivial' correlations and correlations arising from `new physics'.

  17. Dissipation and fluctuation of the relative momentum in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    The dissipation of the relative momentum in nucleus-nucleus collisions is treated in terms of a Langevin equation with a fluctuating force. Equations of motion for first and second moments of the macroscopic variables are derived directly from the Langevin equation. The properties of the fluctuating force which results from random particle exchange are investigated in detail. Drift and diffusion coefficients are calculated microscopically and analytical expressions are given which can be used in any trajectory calculation. An important feature of the model is that the Einstein relation between dissipation and fluctuation turns out to be only a limiting case of a more general expression which included nonthermal fluctuations. By treating the two nuclei as intrinsically equilibrated but not in thermal equilibrium with respect to each other several important aspects of the dissipative behaviour, seen in heavy ion collisions with final energies above the Coloumb barrier, can be understood. (orig.)

  18. Jet energy loss and bulk parton collectivity in nucleus-nucleus collisions at RHIC

    Institute of Scientific and Technical Information of China (English)

    HUANG Huan-Zhong

    2009-01-01

    Nucleus-nucleus collisions at RHIC produce high temperature and high energy density matter which exhibits paxtonic degrees of freedom. We will discuss measurements of nuclear modification factors for light hadrons and non-photonic electrons from heavy quark decays, which reflect the flavor dependence of energy loss of high momentum partons traversing the dense QCD medium. The dense QCD medium responds to energy loss of high momentum patrons in a pattern consistent with that expected from a hydrodynamic fluid. The hadronization of bulk partonic matter exhibits collectivity with effective partonic degrees of freedom. Nuclear collisions at RHIC provide an intriguing environment, where many constituent quark ingredients are readily available for possible formation of exotic particles through quark coalescence or recombinations.

  19. Nonmonotonic Target Excitation Dependence of Pion Clans in Relativistic Nucleus-Nucleus Collisions

    Science.gov (United States)

    Ghosh, Dipak; Deb, Argha; Dutta, Srimonti

    Target excitation dependence of fluctuation of produced pions (i.e. classifying data of the fluctuation pattern on pions on the basis of the number of gray tracks) is studied for nucleus-nucleus collisions at different projectile energies. In each set the experimental multiplicity distribution is compared with the negative binomial distribution (NBD), which is found to describe the experimental distribution quite well. Target excitation dependence is studied in respect of the clan model parameters bar {n}c and bar {N}, which are extracted from the NBD fit parameters bar {n} and k. A detailed comparison between different interactions at the same energy and the same interactions at different energies is also drawn. A nonmonotonic dependence of D2/bar {n} on is revealed, which is also a characteristic of multiplicity fluctuations at RHIC data.

  20. Production of cold fragments in nucleus-nucleus collisions in the Fermi-energy domain

    CERN Document Server

    Veselsky, M

    2007-01-01

    The reaction mechanism of nucleus-nucleus collisions at projectile energies around the Fermi energy is investigated with emphasis on the production of fragmentation-like residues. The results of simulations are compared to experimental mass distributions of elements with Z = 21 - 29 observed in the reactions 86Kr+124,112Sn at 25 AMeV. The model of incomplete fusion is modified and a component of excitation energy of the cold fragment dependent on isospin asymmetry is introduced. The modifications in the model of incomplete fusion appear consistent with both overall model framework and available experimental data. A prediction is provided for the production of very neutron-rich nuclei using a secondary beam of 132Sn where e.g. the reaction 132Sn+238U at 28 AMeV appears as a possible alternative to the use of fragmentation reactions at higher energies.

  1. Nuclear Effects in Neutrino-Nucleus Interactions and the MINERvA Neutrino Nucleus Scattering Program

    Science.gov (United States)

    Morfín, Jorge G.

    2011-09-01

    Nuclear effects of charged current deep inelastic neutrino-iron scattering have been studied in the frame-work of a χ2 analysis of parton distribution functions (PDFs)1. A set of iron PDFs have been extracted which are then used to compute xBj-dependent and Q2-dependent nuclear correction factors for iron structure functions which are required in global analyses of free nucleon PDFs. Upon comparing our results with nuclear correction factors from neutrino-nucleus scattering models and correction factors for l±-iron scattering we find that, except for very high xBj, our correction factors differ in both shape and magnitude from the correction factors of the models and charged-lepton scattering. The MINERvA neutrino-nucleus scattering experiment at Fermilab, will systematically study neutrino nuclear effects off of He, C, Fe and Pb for a more thorough A-dependent study of nuclear PDFs and these correction factors.

  2. Nucleus -nucleus interactions at a few GeV/C per nucleon

    International Nuclear Information System (INIS)

    Introduction: Since the period of the ancient Egyptians people are looking for unusual phenomena, which may enable to give interpretation for nature. Physicists believe that the study of A-A interactions will shed light on the mechanism of high-energy nuclear interactions. It is important to systematize the results of nucleus-nucleus interactions and to have an overall picture of cross-section, multiplicity-distributions, angular distributions, etc It is important to systematize the results of nucleus-nucleus interactions and to have an overall picture of: cross-section, multiplicity-distributions, angular distributions, etc Beams: Beams are mainly from Dubna Synchrophasotron including 1H, 2H, 3He, 4He, 12C, 160,22Ne, 24Mg, 28Si and 32S at 4.1∼ 4.5 GeV/c. Experimental Technique: Stacks of Br-2 emulsion were exposed to 4.1- 4.5 A GeV/c nuclei at Dubna Synchrophasotron. The pellicles of emulsion have the dimensions of 20 cm x 10 cm x 600 μm (undeveloped emulsion). The intensity of the beam was ≡104 particles/cm2 and the beam diameter was approximately 1 cm. The emitted particles are classified to:Shower tracks producing s-particleshaving a relative ionization I*≤ 1.4. Its multiplicity is denoted by ns after the exclusion of tracks having an emission angle θ≤3ο.Grey tracks producing g-particleshaving I* > 1.4 and L>3 mm. Its multiplicity is denoted by ng and does not include those tracks with an emission angle θ≤ 3ο. Black tracks producing b-particleshaving L b and does not include those tracks having an angle of emission θ≤3ο.The band gtracks are both called heavily ionizing tracks producing h-particlesand nh denotes its multiplicity

  3. The Confined Hydrogen Atom with a Moving Nucleus

    Science.gov (United States)

    Fernandez, Francisco M.

    2010-01-01

    We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first-order perturbation theory and show that it is greater than that for the case in which the nucleus is clamped…

  4. A Frame Nucleus on a Two-side Prequantale

    Institute of Scientific and Technical Information of China (English)

    XUShao-xian; WANGShun-qin; MAFei-fei

    2004-01-01

    In this paper, a Frame nucleus and prime elements in a Prequantale are defined. The concrete structure of a Frame prequantic quotient is considered, and the relation between the half-prime element and the Frame nucleus in a two-side Prequantale are obtained.

  5. HEK293 cells express dystrophin Dp71 with nucleus-specific localization of Dp71ab.

    Science.gov (United States)

    Nishida, Atsushi; Yasuno, Sato; Takeuchi, Atsuko; Awano, Hiroyuki; Lee, Tomoko; Niba, Emma Tabe Eko; Fujimoto, Takahiro; Itoh, Kyoko; Takeshima, Yasuhiro; Nishio, Hisahide; Matsuo, Masafumi

    2016-09-01

    The dystrophin gene consists of 79 exons and encodes tissue-specific isoforms. Mutations in the dystrophin gene cause Duchenne muscular dystrophy, of which a substantial proportion of cases are complicated by non-progressive mental retardation. Abnormalities of Dp71, an isoform transcribed from a promoter in intron 62, are a suspected cause of mental retardation. However, the roles of Dp71 in human brain have not been fully elucidated. Here, we characterized dystrophin in human HEK293 cells with the neuronal lineage. Reverse transcription-PCR amplification of the full-length dystrophin transcript revealed the absence of fragments covering the 5' part of the dystrophin cDNA. In contrast, fragments covering exons 64-79 were present. The Dp71 promoter-specific exon G1 was shown spliced to exon 63. We demonstrated that the Dp71 transcript comprised two subisoforms: one lacking exon 78 (Dp71b) and the other lacking both exons 71 and 78 (Dp71ab). Western blotting of cell lysates using an antibody against the dystrophin C-terminal region revealed two bands, corresponding to Dp71b and Dp71ab. Immunohistochemical examination with the dystrophin antibody revealed scattered punctate signals in the cytoplasm and the nucleus. Western blotting revealed one band corresponding to Dp71b in the cytoplasm and two bands corresponding to Dp71b and Dp71ab in the nucleus, with Dp71b being predominant. These results indicated that Dp71ab is a nucleus-specific subisoform. We concluded that Dp71, comprising Dp71b and Dp71ab, was expressed exclusively in HEK293 cells and that Dp71ab was specifically localized to the nucleus. Our findings suggest that Dp71ab in the nucleus contributes to the diverse functions of HEK293 cells.

  6. An increase in intracelluar free calcium ions modulated by cholinergic receptors in rat facial nucleus

    Institute of Scientific and Technical Information of China (English)

    SUN Da-wei; ZHOU Rui; LI Na; ZHANG Qiu-gui; ZHU Fu-gao

    2009-01-01

    Background Ca2+in the central nervous system plays important roles in brain physiology, including neuronal survival and regeneration in rats with injured facial motoneurons. The present research was to study the modulations of intracellular free Ca2+ concentrations by cholinergic receptors in rat facial nucleus, and the mechanisms of the modulations. Methods The fluorescence intensity of facial nucleus in Fluo-3 AM loaded acute brainstem slices was detected by applying intracellular free Ca2+ measurement technique via confocal laser scanning microscope. The changes of fluorescence intensity of facial nucleus indicate the average changes of intracellular free Ca2+ levels of the neurons. Results Acetylcholine was effective at increasing the fluorescence intensity of facial nucleus. Muscarine chlorlde induced a marked increase of fluorescence intensity in a concentration dependent fashion. The enhancement of fluorescence intensity by muscarine chloride was significantly reduced by thapsigargin (depletor of intracellular Ca2+ store; P0.05). And the increase of fluorescence intensity was also significantly inhibited by pirenzepine (M1 subtype selective antagonist; P0.05).Conclusions The data provide the evidence that muscarinic receptors may induce the increase of intracellular free Ca2+ levels through the Ca2+ release of intracellular Ca2+ stores, in a manner related to M1 and M3 subtypes of muscarinic receptors in rat facial nucleus. Nicotine may increase intracellular free Ca2+ concentrations via the influx of extracellular Ca2+ mainly across L-type voltage-gated Ca2+ channels, in a manner related to the α4β2 subtype of nicotinic receptors.

  7. 神经激肽B及其受体在生殖轴中的作用%The role of neurokinin B and its receptor in hypothalamic-pituitary-gonad axis

    Institute of Scientific and Technical Information of China (English)

    黄莹莹

    2013-01-01

    Kisspoptin signaling plays an essential role in the onset of puberty and reproductive development.Recently studies implicate that steroid-responsive NKB,kisspeptin,NK3 R,and estrogen receptor α (ERα) coexpress in arcuate nucleus of hypothalamus of variety of mammalian species and regulate the secretion of gonadotrophic hormone.The function of neurons in the hypothalamus is to regulate the estrogen negative feedback on gonadotropin-releasing hormone (GnRH) secretion.Loss of function of neurokinin B (NKB) or its receptor,the neurokinin-3 receptor produces idiopathic hypogonadotropic hypogonadism.These studies demonstrate NKB and neurokinin-3 receptor as the essential elements of the human reproductive axis.%目前的研究认为Kisspeptin信号系统在调控青春启动及生殖发育方面发挥关键作用.许多哺乳动物有神经激肽B(neurokinin B,NKB)、kisspeptin及雌激素0受体在下丘脑弓状核共表达,它们的作用是对雌激素的负反馈产生应答,调节促性腺激素释放激素的分泌.NKB或其受体基因的失活突变与不伴有嗅觉异常和其他生长发育缺陷的散发性低促性腺素性功能减退症有关,说明NKB及其受体在生殖轴的启动中起着重要作用.

  8. Evolutionary implications of localization of the signaling scaffold protein parafusin to both cilia and the nucleus.

    Science.gov (United States)

    Satir, Birgit Hegner; Wyroba, Elzbieta; Liu, Li; Lethan, Mette; Satir, Peter; Christensen, Søren Tvorup

    2015-02-01

    Parafusin (PFUS), a 63 kDa protein first discovered in the eukaryote Paramecium and known for its role in apicomplexan exocytosis, provides a model for the common origin of cellular systems employing scaffold proteins for targeting and signaling. PFUS is closely related to eubacterial rather than archeal phosphoglucomutases (PGM) - as we proved by comparison of their 88 sequences - but has no PGM activity. Immunofluorescence microscopy analysis with a PFUS-specific peptide antibody showed presence of this protein around the base region of primary cilia in a variety of mammalian cell types, including mouse embryonic (MEFs) and human foreskin fibroblasts (hFFs), human carcinoma stem cells (NT-2 cells), and human retinal pigment epithelial (RPE) cells. Further, PFUS localized to the nucleus of fibroblasts, and prominently to nucleoli of MEFs. Localization studies were confirmed by Western blot analysis, showing that the PFUS antibody specifically recognizes a single protein of ca. 63 kDa in both cytoplasmic and nuclear fractions. Finally, immunofluorescence microscopy analysis showed that PFUS localized to nuclei and cilia in Paramecium. These results support the suggestion that PFUS plays a role in signaling between nucleus and cilia, and that the cilium and the nucleus both evolved around the time of eukaryotic emergence. We hypothesize that near the beginnings of eukaryotic cell evolution, scaffold proteins such as PFUS arose as peripheral membrane protein identifiers for cytoplasmic membrane trafficking and were employed similarly during the subsequent evolution of exocytic, nuclear transport, and ciliogenic mechanisms.

  9. Neuropeptide Y infusion into the shell region of the rat nucleus accumbens increases extracellular levels of dopamine

    DEFF Research Database (Denmark)

    Sørensen, Gunnar; Wegener, Gregers; Hasselstrøm, Jørgen;

    2009-01-01

    Increases in extracellular dopamine in the shell region of the nucleus accumbens are centrally involved in mediating reinforcement of addictive drugs. Neuropeptide Y (NPY) and its receptors are present in the nucleus accumbens and have been implicated in addiction mechanisms. This study further...... explored the potential role of NPY in addiction mechanisms using microdialysis to measure extracellular dopamine in vivo after infusion of NPY directly into the accumbal shell region of adult rats. NPY was found to dose-dependently increase extracellular dopamine levels, indicating that NPY could play...

  10. Spiral-based microfluidic device for long-term time course imaging of Neurospora crassa with single nucleus resolution.

    Science.gov (United States)

    Lee, Kang Kug; Labiscsak, Laszlo; Ahn, Chong H; Hong, Christian I

    2016-09-01

    Real-time imaging of fluorescent reporters plays a critical role in elucidating fundamental molecular mechanisms including circadian rhythms in the model filamentous fungus, Neurospora crassa. However, monitoring N. crassa for an extended period of time with single nucleus resolution is a technically challenging task due to hyphal growth that rapidly moves beyond a region of interest during microscopy experiments. In this report, we have proposed a two-dimensional spiral-based microfluidic platform and applied for monitoring the single-nucleus dynamics in N. crassa for long-term time course experiments. PMID:27345439

  11. Confronting electron and neutrino-nucleus interactions: Can the axial mass anomaly be resolved?

    Science.gov (United States)

    Benhar, Omar

    2014-04-01

    Comparison between electron- and neutrino-nucleus scattering data suggests that the so-called axial mass anomaly — i.e., the large disagreement between the value of the nucleon axial mass extracted from the analysis of neutrino interactions with carbon and oxygen and that obtained from deuteron data — is a manifestation of the difficulties in the interpretation of the flux averaged neutrino cross-sections. In this short review, I discuss the role of reaction mechanisms leading to the excitation of two particle-two hole final states of the target nucleus, which are believed to be responsible for the observed excess of quasielastic events, and argue that taking into account their effect may help to reconcile the sizeably different values of the axial mass reported by the MiniBooNe and NOMAD Collaborations.

  12. Spontaneous fission of superheavy nucleus $^{286}$Fl

    CERN Document Server

    Poenaru, Dorin N

    2016-01-01

    The decimal logarithm of spontaneous fission half-life of the superheavy nucleus $^{286}$Fl experimentally determined is $\\log_{10} T_f^{exp} (s) = -0.632$. We present a method to calculate the half-life based on the cranking inertia and the deformation energy, functions of two independent surface coordinates, using the best asymmetric two center shell model. In the first stage we study the statics. At a given mass asymmetry up to about $\\eta=0.5$ the potential barrier has a two hump shape, but for larger $\\eta$ it has only one hump. The touching point deformation energy versus mass asymmetry shows the three minima, produced by shell effects, corresponding to three decay modes: spontaneous fission, cluster decay and $\\alpha$~decay. The least action trajectory is determined in the plane $(R,\\eta)$ where $R$ is the separation distance of the fission fragments and $\\eta$ is the mass asymmetry. We may find a sequence of several trajectories one of which gives the least action. The parametrization with two deforma...

  13. Functional network inference of the suprachiasmatic nucleus.

    Science.gov (United States)

    Abel, John H; Meeker, Kirsten; Granados-Fuentes, Daniel; St John, Peter C; Wang, Thomas J; Bales, Benjamin B; Doyle, Francis J; Herzog, Erik D; Petzold, Linda R

    2016-04-19

    In the mammalian suprachiasmatic nucleus (SCN), noisy cellular oscillators communicate within a neuronal network to generate precise system-wide circadian rhythms. Although the intracellular genetic oscillator and intercellular biochemical coupling mechanisms have been examined previously, the network topology driving synchronization of the SCN has not been elucidated. This network has been particularly challenging to probe, due to its oscillatory components and slow coupling timescale. In this work, we investigated the SCN network at a single-cell resolution through a chemically induced desynchronization. We then inferred functional connections in the SCN by applying the maximal information coefficient statistic to bioluminescence reporter data from individual neurons while they resynchronized their circadian cycling. Our results demonstrate that the functional network of circadian cells associated with resynchronization has small-world characteristics, with a node degree distribution that is exponential. We show that hubs of this small-world network are preferentially located in the central SCN, with sparsely connected shells surrounding these cores. Finally, we used two computational models of circadian neurons to validate our predictions of network structure.

  14. Functional network inference of the suprachiasmatic nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Abel, John H.; Meeker, Kirsten; Granados-Fuentes, Daniel; St. John, Peter C.; Wang, Thomas J.; Bales, Benjamin B.; Doyle, Francis J.; Herzog, Erik D.; Petzold, Linda R.

    2016-04-04

    In the mammalian suprachiasmatic nucleus (SCN), noisy cellular oscillators communicate within a neuronal network to generate precise system-wide circadian rhythms. Although the intracellular genetic oscillator and intercellular biochemical coupling mechanisms have been examined previously, the network topology driving synchronization of the SCN has not been elucidated. This network has been particularly challenging to probe, due to its oscillatory components and slow coupling timescale. In this work, we investigated the SCN network at a single-cell resolution through a chemically induced desynchronization. We then inferred functional connections in the SCN by applying the maximal information coefficient statistic to bioluminescence reporter data from individual neurons while they resynchronized their circadian cycling. Our results demonstrate that the functional network of circadian cells associated with resynchronization has small-world characteristics, with a node degree distribution that is exponential. We show that hubs of this small-world network are preferentially located in the central SCN, with sparsely connected shells surrounding these cores. Finally, we used two computational models of circadian neurons to validate our predictions of network structure.

  15. Functional network inference of the suprachiasmatic nucleus.

    Science.gov (United States)

    Abel, John H; Meeker, Kirsten; Granados-Fuentes, Daniel; St John, Peter C; Wang, Thomas J; Bales, Benjamin B; Doyle, Francis J; Herzog, Erik D; Petzold, Linda R

    2016-04-19

    In the mammalian suprachiasmatic nucleus (SCN), noisy cellular oscillators communicate within a neuronal network to generate precise system-wide circadian rhythms. Although the intracellular genetic oscillator and intercellular biochemical coupling mechanisms have been examined previously, the network topology driving synchronization of the SCN has not been elucidated. This network has been particularly challenging to probe, due to its oscillatory components and slow coupling timescale. In this work, we investigated the SCN network at a single-cell resolution through a chemically induced desynchronization. We then inferred functional connections in the SCN by applying the maximal information coefficient statistic to bioluminescence reporter data from individual neurons while they resynchronized their circadian cycling. Our results demonstrate that the functional network of circadian cells associated with resynchronization has small-world characteristics, with a node degree distribution that is exponential. We show that hubs of this small-world network are preferentially located in the central SCN, with sparsely connected shells surrounding these cores. Finally, we used two computational models of circadian neurons to validate our predictions of network structure. PMID:27044085

  16. The new magic nucleus 96Zr

    International Nuclear Information System (INIS)

    The 96Zr nucleus is expected to be magic due to the subshell closures at Z = 40 and N = 56. Recent gamma-spectroscopic studies involving in-beam techniques and beta decay certainly revealed a remarkably simple level pattern consisting of the 1,750 keV 2+ - 2,439 keV 3+ doublet, a few levels decaying to the 3- octupole state by strong E1 or E2 transitions, and a band built on the shape isomeric first excited 0+ state. While quadrupole vibrational collectivity is restricted to this latter intruder band the octupole mode is expected to be strong, according to systematics and an earlier lifetime result for the 3- state. since low-lying particle-hole excitations, and a strong octupole mode in particular, are typical for magic nuclei like 208Pb it is important to test to what extent 96Zr resembles the well known magic nuclei. In this paper, inelastic deuteron scattering and RPA studies show that the lowest states of doubly closed subshell 96Zr are particle-hole excitations, the first 2+ state being a neutron excitation of 3s1/2 2d5/2-1 type. The octupole collectively is enhanced by a factor of about two with respect to 90Zr due mainly to the contribution of 1h1 1/2 2d5/2-1 neutron excitations, suggesting an unusually high B(E3) value

  17. Observation of the antimatter helium-4 nucleus.

    Science.gov (United States)

    2011-05-19

    High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang; in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high-energy accelerator of heavy nuclei provides an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus (4He), also known as the anti-α (α), consists of two antiprotons and two antineutrons (baryon number B = -4). It has not been observed previously, although the α-particle was identified a century ago by Rutherford and is present in cosmic radiation at the ten per cent level. Antimatter nuclei with B Collider (RHIC; ref. 6) in 10(9) recorded gold-on-gold (Au+Au) collisions at centre-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon pair. The yield is consistent with expectations from thermodynamic and coalescent nucleosynthesis models, providing an indication of the production rate of even heavier antimatter nuclei and a benchmark for possible future observations of 4He in cosmic radiation.

  18. Depolarizing actions of hydrogen sulfide on hypothalamic paraventricular nucleus neurons.

    Directory of Open Access Journals (Sweden)

    C Sahara Khademullah

    Full Text Available Hydrogen sulfide (H2S is a novel neurotransmitter that has been shown to influence cardiovascular functions as well and corticotrophin hormone (CRH secretion. Since the paraventricular nucleus of the hypothalamus (PVN is a central relay center for autonomic and endocrine functions, we sought to investigate the effects of H2S on the neuronal population of the PVN. Whole cell current clamp recordings were acquired from the PVN neurons and sodium hydrosulfide hydrate (NaHS was bath applied at various concentrations (0.1, 1, 10, and 50 mM. NaHS (1, 10, and 50 mM elicited a concentration-response relationship from the majority of recorded neurons, with almost exclusively depolarizing effects following administration. Cells responded and recovered from NaHS administration quickly and the effects were repeatable. Input differences from baseline and during the NaHS-induced depolarization uncovered a biphasic response, implicating both a potassium and non-selective cation conductance. The results from the neuronal population of the PVN shed light on the possible physiological role that H2S has in autonomic and endocrine function.

  19. GUSTATORY RESPONSES OF NEURONS IN THE PARABRACHIAL NUCLEUS OF RATS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective:To investigate the gustatory neural response of the neurons to five basic taste stimuli in the parabrachial nucleus(PBN),Methods:Evoked responses from PBN taste neurons to tastants were recorded using standard extracellular microelectrode technique.Results:46 taste neurons were recorded in PBN,and most of them were broadly responsive.On the basis of their most effective taste stimuli,these taste neurons were classified into five types.Those are NaCl-,HCl-,quinine-sucrose-,and monosodium glutamate(MSG)-best neurons.Except for the quinine-best neurons,the responses of each best-stimulus category to its best stimulus were significantly stronger than those of others(P<0.01),The results of correlation analysis showed that the correlations between sucrose and each of the other 4 tastants were smaller than those among others.Conclusion:The results suggest that PBN taste neurons probably play an important role in discriminating for hedonic taste.

  20. GUSTATORY RESPONSES OF NEURONS IN THE PARABRACHIAL NUCLEUS OF RATS

    Institute of Scientific and Technical Information of China (English)

    黄涛; 闫剑群; 康怡

    2002-01-01

    Objective To investigate the gustatory neural r esponse of the neurons to five basic taste stimuli in the parabrachial nucleus ( PBN). Methods Evoked responses from PBN taste neurons to t astants were recorded using standard extracellular microelectrode technique. Results 46 taste neurons were recorded in PBN, and most of th em were broadly respo nsive. On the basis of their most effective taste stimuli, these taste neurons w ere classified into five types. Those are NaCl-, HCl-, quinine-, sucrose-, and monosodium glutamate (MSG)-best neurons. Except for the quinine-best neur ons, the responses of each best-stimulus category to its best stimulus were sig nificantly stronger than those of others (P<0.01). The results of correlati on analysis showed that the correlations between sucrose and each of the other 4 tastants were smaller than those among others. Conclusion Th e results suggest that PBN taste neurons probably play an important role in disc riminating for hedonic taste.

  1. The Subthalamic Nucleus, Limbic Function, and Impulse Control.

    Science.gov (United States)

    Rossi, P Justin; Gunduz, Aysegul; Okun, Michael S

    2015-12-01

    It has been well documented that deep brain stimulation (DBS) of the subthalamic nucleus (STN) to address some of the disabling motor symptoms of Parkinson's disease (PD) can evoke unintended effects, especially on non-motor behavior. This observation has catalyzed more than a decade of research concentrated on establishing trends and identifying potential mechanisms for these non-motor effects. While many issues remain unresolved, the collective result of many research studies and clinical observations has been a general recognition of the role of the STN in mediating limbic function. In particular, the STN has been implicated in impulse control and the related construct of valence processing. A better understanding of STN involvement in these phenomena could have important implications for treating impulse control disorders (ICDs). ICDs affect up to 40% of PD patients on dopamine agonist therapy and approximately 15% of PD patients overall. ICDs have been reported to be associated with STN DBS. In this paper we will focus on impulse control and review pre-clinical, clinical, behavioral, imaging, and electrophysiological studies pertaining to the limbic function of the STN. PMID:26577509

  2. Implications of gamma band activity in the pedunculopontine nucleus.

    Science.gov (United States)

    Garcia-Rill, E; Luster, B; D'Onofrio, S; Mahaffey, S; Bisagno, V; Urbano, F J

    2016-07-01

    The fact that the pedunculopontine nucleus (PPN) is part of the reticular activating system places it in a unique position to modulate sensory input and fight-or-flight responses. Arousing stimuli simultaneously activate ascending projections of the PPN to the intralaminar thalamus to trigger cortical high-frequency activity and arousal, as well as descending projections to reticulospinal systems to alter posture and locomotion. As such, the PPN has become a target for deep brain stimulation for the treatment of Parkinson's disease, modulating gait, posture, and higher functions. This article describes the latest discoveries on PPN physiology and the role of the PPN in a number of disorders. It has now been determined that high-frequency activity during waking and REM sleep is controlled by two different intracellular pathways and two calcium channels in PPN cells. Moreover, there are three different PPN cell types that have one or both calcium channels and may be active during waking only, REM sleep only, or both. Based on the new discoveries, novel mechanisms are proposed for insomnia as a waking disorder. In addition, neuronal calcium sensor protein-1 (NCS-1), which is over expressed in schizophrenia and bipolar disorder, may be responsible for the dysregulation in gamma band activity in at least some patients with these diseases. Recent results suggest that NCS-1 modulates PPN gamma band activity and that lithium acts to reduce the effects of over expressed NCS-1, accounting for its effectiveness in bipolar disorder. PMID:26597124

  3. Nonthermal Fluctuations and Mechanics of the Active Cell Nucleus

    CERN Document Server

    Smith, K; Byrd, H; MacKintosh, F C; Kilfoil, M L

    2013-01-01

    We present direct measurements of fluctuations in the nucleus of yeast cells. While prior work has shown these fluctuations to be active and non-thermal in character, their origin and time dependence are not understood. We show that nuclear fluctuations can be quantitatively understood by uncorrelated, active force fluctuations driving a nuclear medium that is dominated by an uncondensed DNA solution, for which we perform rheological measurements on an in vitro model system under similar conditions to what is expected in the nucleus. We conclude that the eukaryotic nucleus of living cells is a nonequilibrium soft material whose fluctuations are actively driven, and are far from thermal in their time dependence.

  4. Variability of the Radio Nucleus of the Galaxy M81

    CERN Document Server

    Bietenholz, M F; Rupen, M P

    1997-01-01

    M81 is the nearest galaxy with an active galactic nucleus, with the possibly exception of Cen A. The nucleus is exceptionally compact. Here we present results from new VLA and VLBI observations of the nucleus of M81. The VLA shows that its flux density is variable by 50% on a timescale of weeks. The spectral index is also somewhat variable on the same timescale. The VLBI imaging results show that there is structure on scales <0.5 mas, and that this structure is variable, also on a timescale of weeks.

  5. Quarkonium-nucleus bound states from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Beane, S.  R. [Univ. of Washington, Seattle, WA (United States); Chang, E. [Univ. of Washington, Seattle, WA (United States); Cohen, S.  D. [Univ. of Washington, Seattle, WA (United States); Detmold, W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lin, H. -W. [Univ. of Washington, Seattle, WA (United States); Orginos, K. [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Parreño, A. [Univ., de Barcelona, Marti Franques (Spain); Savage, M.  J. [Univ. of Washington, Seattle, WA (United States)

    2015-06-11

    Quarkonium-nucleus systems are composed of two interacting hadronic states without common valence quarks, which interact primarily through multi-gluon exchanges, realizing a color van der Waals force. We present lattice QCD calculations of the interactions of strange and charm quarkonia with light nuclei. Both the strangeonium-nucleus and charmonium-nucleus systems are found to be relatively deeply bound when the masses of the three light quarks are set equal to that of the physical strange quark. Extrapolation of these results to the physical light-quark masses suggests that the binding energy of charmonium to nuclear matter is B < 40 MeV.

  6. The dorsomedial shell of the nucleus accumbens facilitates cocaine-induced locomotor activity during the induction of behavioral sensitization.

    Science.gov (United States)

    Todtenkopf, M S; Carreiras, T; Melloni, R H; Stellar, J R

    2002-04-01

    The mesolimbic dopamine system has been intensely studied as the neural circuit mediating the locomotor response to psychostimulants and behavioral sensitization. In particular, the dopaminergic innervation of the nucleus accumbens has been implicated as a site responsible for the manifestations of behavioral sensitization. Previous studies have demonstrated an augmented release of dopamine in the nucleus accumbens upon a systemic injection of a psychostimulant. In addition, alterations in the dopaminergic innervation patterns in this brain region have been demonstrated in animals that received repeated injections of cocaine. Furthermore, lesions of projection sites that have terminations in the nucleus accumbens have demonstrated alterations in psychostimulant induced locomotion, both acutely, as well as in sensitization paradigms. Since dopamine in the nucleus accumbens is believed to regulate several excitatory amino acid inputs, the present study examined the effects of a localized electrolytic lesion in the dorsomedial shell of the nucleus accumbens in order to better understand the functional role this brain region has in behavioral sensitization. All animals received bi-daily injections of 15 mg/kg i.p. cocaine. Only those demonstrating behavioral sensitization after a subsequent challenge dose were included in the analysis. Following acute exposure to cocaine, lesioned animals did not show any difference in their locomotor response when compared with sham controls. However, after repeated exposure to cocaine, sensitized animals demonstrated a significant attenuation in locomotor behavior when compared with sensitized sham controls. This decrease in horizontal locomotion persisted 2 days into withdrawal, yet dissipated in the sensitized animals that were challenged 2 weeks following their last injection. The data presented here demonstrate that the dorsomedial shell of the nucleus accumbens plays an important role in the initial stages of behavioral

  7. Encoding of aversion by dopamine and the nucleus accumbens

    Directory of Open Access Journals (Sweden)

    James Edgar Mccutcheon

    2012-09-01

    Full Text Available Adaptive motivated behavior requires rapid discrimination between beneficial and harmful stimuli. Such discrimination leads to the generation of either an approach or rejection response, as appropriate, and enables organisms to maximize reward and minimize punishment. Classically, the nucleus accumbens (NAc and the dopamine projection to it are considered an integral part of the brain’s reward circuit, i.e., they direct approach and consumption behaviors and underlie positive reinforcement. This reward-centered framing ignores important evidence about the role of this system in encoding aversive events. One reason for bias towards reward is the difficulty in designing experiments in which animals repeatedly experience punishments; another is the challenge in dissociating the response to an aversive stimulus itself from the reward/relief experienced when an aversive stimulus is terminated. Here, we review studies that employ techniques with sufficient time resolution to measure responses in ventral tegmental area (VTA and NAc to aversive stimuli as they are delivered. We also present novel findings showing that the same stimulus – intraoral infusion of sucrose – has differing effects on NAc shell dopamine release depending on the prior experience. Here, for some rats, sucrose was rendered aversive by explicitly pairing it with malaise in a conditioned taste aversion paradigm. Thereafter, sucrose infusions led to a suppression of dopamine with a similar magnitude and time course to intra-oral infusions of a bitter quinine solution. The results are discussed in the context of regional differences in dopamine signaling and the implications of a pause in phasic dopamine release within the NAc shell. Together with our data, the emerging literature suggests an important role for differential phasic dopamine signaling in aversion versus reward.

  8. Encoding of aversion by dopamine and the nucleus accumbens.

    Science.gov (United States)

    McCutcheon, James E; Ebner, Stephanie R; Loriaux, Amy L; Roitman, Mitchell F

    2012-01-01

    Adaptive motivated behavior requires rapid discrimination between beneficial and harmful stimuli. Such discrimination leads to the generation of either an approach or rejection response, as appropriate, and enables organisms to maximize reward and minimize punishment. Classically, the nucleus accumbens (NAc) and the dopamine projection to it are considered an integral part of the brain's reward circuit, i.e., they direct approach and consumption behaviors and underlie positive reinforcement. This reward-centered framing ignores important evidence about the role of this system in encoding aversive events. One reason for bias toward reward is the difficulty in designing experiments in which animals repeatedly experience punishments; another is the challenge in dissociating the response to an aversive stimulus itself from the reward/relief experienced when an aversive stimulus is terminated. Here, we review studies that employ techniques with sufficient time resolution to measure responses in ventral tegmental area and NAc to aversive stimuli as they are delivered. We also present novel findings showing that the same stimulus - intra-oral infusion of sucrose - has differing effects on NAc shell dopamine release depending on the prior experience. Here, for some rats, sucrose was rendered aversive by explicitly pairing it with malaise in a conditioned taste aversion paradigm. Thereafter, sucrose infusions led to a suppression of dopamine with a similar magnitude and time course to intra-oral infusions of a bitter quinine solution. The results are discussed in the context of regional differences in dopamine signaling and the implications of a pause in phasic dopamine release within the NAc shell. Together with our data, the emerging literature suggests an important role for differential phasic dopamine signaling in aversion vs. reward. PMID:23055953

  9. Structural Description of Polyaromatic Nucleus in Residue

    Institute of Scientific and Technical Information of China (English)

    Zhang Huicheng; Yan Yongjie; Sun Wanfu; Wang Jifeng

    2007-01-01

    The proton nuclear magnetic resonance spectroscopy(1H-NMR),the synchronous fluorescence spectrometry(SFS)and the rutheniam ions catalyzed oxidation(RICO)method wen used to determine the chemical structure of polyaromatic nucleus in Oman residue fractions.The results of1H-NMR analyses showed that the average numbers of aromatic rings in the aromatics,resins and asphaltenes units were 3.2,5.6 and 8.2.respectively.SFS was used to investigate the distribution of aromatic tings in residue fractions,the main distribution range of aromatic rings in aromatics,resins and asphaltenes were 3-4 rings,3-5 rings and more than 5 tings,respectively.The aromatic network in residue fractions was oxidized to produce numerous carboxylic acids.The types and content of benzenepolycarboxylic acids,such as phthalic acid,benzenetricarboxylic acids,benzenetetracarbOxylic acids,benzenepentacarboxylic acid and benzenehexacarboxylic acid disclosed the condensed types of aromatic nuclei in the core.The biphenyl fraction(BIPH),the cata-condensed fraction(CATA),the peri-condensed fraction(PERI)and the condensed index(BCI)were calculated based on the benzenepolycarboxylic acids formed.The results implied that there was less biphenyl type structures in all residue fractions.The aromatics fraction was almost composed of the cata-condensed type system,and the asphaltenes fraction was wholly composed of the peri-condensed type system,while in the resins fraction co-existed the two types,herein the peri-condensed type Was predominant over the cata-condensed type.Based on the analytical results obtained in the study,the components-aromatics,resins and asphaltenes-were given the likely structural models.

  10. Study of chemical equilibrium in nucleus-nucleus collisions at AGS and SPS energies

    CERN Document Server

    Becattini, F; Keränen, A; Manninen, J; Stock, Reinhard

    2003-01-01

    We present a detailed study of chemical freeze-out in nucleus-nucleus collisions at beam energies of 11.6, 30, 40, 80 and 158A GeV. By analyzing hadronic multiplicities within the statistical hadronization approach, we have studied the strangeness production as a function of centre of mass energy and of the parameters of the source. We have tested and compared different versions of the statistical model, with special emphasis on possible explanations of the observed strangeness hadronic phase space under-saturation. We show that, in this energy range, the use of hadron yields at midrapidity instead of in full phase space artificially enhances strangeness production and could lead to incorrect conclusions as far as the occurrence of full chemical equilibrium is concerned. In addition to the basic model with an extra strange quark non-equilibrium parameter, we have tested three more schemes: a two-component model superimposing hadrons coming out of single nucleon-nucleon interactions to those emerging from larg...

  11. Nucleus--nucleus interactions in the inner crust of neutron stars

    CERN Document Server

    Kobyakov, D

    2016-01-01

    The interaction between nuclei in the inner crust of neutron stars consists of two contributions, the so-called "direct" interaction and an "induced" one due to density changes in the neutron fluid. For large nuclear separations $r$ the contributions from nuclear forces to each of these terms are shown to be nonzero. In the static limit they are equal in magnitude but have opposite signs and they cancel exactly. We analyze earlier results on effective interactions in the light of this finding. We consider the properties of long-wavelength collective modes and, in particular, calculate the degree of mixing between the lattice phonons and the phonons in the neutron superfluid. Using microscopic theory, we calculate the net non-Coulombic contribution to the nucleus--nucleus interaction and show that, for large $r$, the leading term is due to exchange of two phonons and varies as $1/r^7$: it is an analog of the Casimir--Polder interaction between neutral atoms.

  12. Nuclear mean field and double-folding model of the nucleus-nucleus optical potential

    CERN Document Server

    Khoa, Dao T; Loan, Doan Thi; Loc, Bui Minh

    2016-01-01

    Realistic density dependent CDM3Yn versions of the M3Y interaction have been used in an extended Hartree-Fock (HF) calculation of nuclear matter (NM), with the nucleon single-particle potential determined from the total NM energy based on the Hugenholtz-van Hove theorem that gives rise naturally to a rearrangement term (RT). Using the RT of the single-nucleon potential obtained exactly at different NM densities, the density- and energy dependence of the CDM3Yn interactions was modified to account properly for both the RT and observed energy dependence of the nucleon optical potential. Based on a local density approximation, the double-folding model of the nucleus-nucleus optical potential has been extended to take into account consistently the rearrangement effect and energy dependence of the nuclear mean-field potential, using the modified CDM3Yn interactions. The extended double-folding model was applied to study the elastic $^{12}$C+$^{12}$C and $^{16}$O+$^{12}$C scattering at the refractive energies, wher...

  13. Electromagnetic probes of a pure-glue initial state in nucleus-nucleus collisions at LHC

    CERN Document Server

    Vovchenko, V; Gorenstein, M I; Satarov, L M; Mishustin, I N; Kämpfer, B; Stoecker, H

    2016-01-01

    Partonic matter produced in the early stage of ultrarelativistic nucleus-nucleus collisions is assumed to be composed mainly of gluons, and quarks and antiquarks are produced at later times. To study the implications of such a scenario, the dynamical evolution of the chemically nonequilibrated system is described by the ideal (2+1)-dimensional hydrodynamics with a time dependent (anti)quark fugacity. The equation of state interpolates linearly between the lattice data for the pure gluonic matter and the lattice data for the chemically equilibrated quark-gluon plasma. The spectra and elliptic flows of thermal dileptons and photons are calculated for central Pb+Pb collisions at the LHC energy of $\\sqrt{s_{_{\\rm NN}}} = 2.76$ TeV. We test the sensitivity of the results to the choice of equilibration times, including also the case where the complete chemical equilibrium of partons is reached already at the initial stage. It is shown that a suppression of quarks at early times leads to a significant reduction of t...

  14. Statistical Model of the Early Stage of nucleus-nucleus collisions with exact strangeness conservation

    CERN Document Server

    Poberezhnyuk, R V; Gorenstein, M I

    2015-01-01

    The Statistical Model of the Early Stage, SMES, describes a transition between confined and deconfined phases of strongly interacting matter created in nucleus-nucleus collisions. The model was formulated in the late 1990s for central Pb+Pb collisions at the CERN SPS energies. It predicted several signals of the transition (onset of deconfinement) which were later observed by the NA49 experiment. The grand canonical ensemble was used to calculate entropy and strangeness production. This approximation is valid for reactions with mean multiplicities of particles carrying conserved charges being significantly larger than one. Recent results of NA61/SHINE on hadron production in inelastic p+p interactions suggest that the deconfinement may also take place in these reactions. However, in this case mean multiplicity of particles with non-zero strange charge is smaller than one. Thus for the modeling of p+p interactions the exact strangeness conservation has to be implemented in the SMES. This extension of the SMES ...

  15. Relativistic transport approach for nucleus-nucleus collisions based on a NJL lagrangian

    CERN Document Server

    Ehehalt, W; Ehehalt, Wolfgang; Cassing, Wolfgang

    1995-01-01

    We formulate a covariant transport approach for high energy nucleus-nucleus collisions where the real part of the hadron selfenergies is evaluated on the basis of a NJL-type Lagrangian for the quark degrees of freedom. The parameters of the model Lagrangian are fixed by the Gell-Mann, Oakes and Renner relation, the pion-nucleon \\Sigma-term, the nucleon energy as well as the nuclear binding energy at saturation density \\rho_0. We find the resulting scalar and vector selfenergies for nucleons to be well in line with either Dirac-Brueckner results or those from the phenomenological optical potential when accounting for a swelling of the nucleon at finite nuclear matter density. The imaginary part of the hadron selfenergies is determined by a string fragmentation model which accounts for the in-medium mass of hadrons in line with the chiral dynamics employed. The applicability of the 'chiral' transport approach is demonstrated in comparison with experimental data from SIS to SPS energies. The enhancement of the K...

  16. EOS: A time projection chamber for the study of nucleus-nucleus collisions at the Bevalac

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, H.G.; Odyniec, G.; Rai, G.; Seidl, P.

    1986-12-01

    The conceptual design is presented for a detector to identify and measure (..delta..p/p approx. = 1%) most of the 200 or so mid-rapidity charged particles (p, d, t, /sup 3/He, /sup 4/He, ..pi../sup + -/, K/sup + -/) produced in each central nucleus-nucleus collision (Au + Au) at Bevalac energies, as well as K/sub 3//sup 0/ and ..lambda../sup 0/. The beam particles and heavy spectator fragments are excluded from the detection volume by means of a central vacuum pipe. Particle identification is achieved by a combination of dE/dx measurements in the TPC, and of time-of-flight measurements in a scintillator array. The TPC is single-ended and its end cap is entirely covered with cathode pads (about 25,000 pads and about 1000 anode wires). A non-uniform pad distribution is proposed to accommodate the high multiplicity of particles emitted at forward angles. The performance of the detector is assessed with regard to multihit capability, tracking, momentum resolution, particle identification, ..lambda../sup 0/ reconstruction, space charge effects, field non-uniformity, dynamic range, data acquisition rate, and data analysis rate. 72 refs., 48 figs., 11 tabs.

  17. Energy-Dependence of Nucleus-Nucleus Potential and Friction Parameter in Fusion Reactions

    CERN Document Server

    Wen, Kai; Li, Zhu-Xia; Wu, Xi-Zhen; Zhang, Ying-Xun; Zhou, Shan-Gui

    2014-01-01

    Applying a macroscopic reduction procedure on the improved quantum molecular dynamics (ImQMD), the energy dependences of the nucleus-nucleus potential, the friction parameter, and the random force characterizing a one-dimensional Langevin-type description of the heavy-ion fusion process are investigated. Systematic calculations with the ImQMD show that the fluctuation-dissipation relation found in the symmetric head-on fusion reactions at energies just above the Coulomb barrier fades out when the incident energy increases. It turns out that this dynamical change with increasing incident energy is caused by a specific behavior of the friction parameter which directly depends on the microscopic dynamical process, i.e., on how the collective energy of the relative motion is transferred into the intrinsic excitation energy. It is shown microscopically that the energy dissipation in the fusion process is governed by two mechanisms: One is caused by the nucleon exchanges between two fusing nuclei, and the other is ...

  18. Semiclassical model for single-particle transitions in nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    A previously elaborated semiclassical one-body model for the dynamics of a single particle, moving in two potentials, in heavy-ion reactions or in fissioning systems has been extended with respect to the inclusion of angular momenta and more realistic separable potentials. The collective relative motion is assumed to proceed along a trajectory which is calculated from classical equations of motion including conservative and phenomenological friction forces. The formalism has been derived involving three-dimensional trajectories for symmetric as well as for asymmetric nucleus-nucleus systems. The model allows for the calculation of correct quantum mechanical transition amplitudes to final bound and continuum states. It has been applied for the investigation of the excitation of a neutron during a fission process, covering also non-statistical differential emission probabilities. From the numerical calculations, using parameters adapted to 252Cf(sf), one can conclude that in the underlying model without 'sudden' processes the energy spectrum consists of two parts. The low lying component is created in the neck region while a high lying part seems to be governed mainly by the dynamics of the underlying collective motion rather than by the specific initial conditions. (orig.)

  19. Isotope Dependence of Superheavy Nucleus Formation Cross Section

    Institute of Scientific and Technical Information of China (English)

    LIU Zu-Hua; BAG Jing-Dong

    2006-01-01

    The dynamical process in the superheavy nucleus synthesis is studied on the basis of the two-dimensional Smolu-chowski equation. Special attention is paid to the isotope dependence of the cross section for the superheavy nucleus formation by means of making a comparison among the reaction systems of 54Fe + 204Pb, 56Fe + 206Pb, and 58Fe + 208Pb. It is found by this comparison that the formation cross section is very sensitive to the conditional saddle-point height and the neutron separation energy of the compound nucleus. Reaction systems with lower height of conditional saddle-point and smaller neutron separation energy are more favourable for the synthesis of the superheavy nucleus.

  20. Red nucleus connectivity as revealed by constrained spherical deconvolution tractography.

    Science.gov (United States)

    Milardi, Demetrio; Cacciola, Alberto; Cutroneo, Giuseppina; Marino, Silvia; Irrera, Mariangela; Cacciola, Giorgio; Santoro, Giuseppe; Ciolli, Pietro; Anastasi, Giuseppe; Calabrò, Rocco Salvatore; Quartarone, Angelo

    2016-07-28

    Previous Diffusion Tensor Imaging studies have demonstrated that the human red nucleus is widely interconnected with sensory-motor and prefrontal cortices. In this study, we assessed red nucleus connectivity by using a multi-tensor model called non- negative Constrained Spherical Deconvolution (CSD), which is able to resolve more than one fiber orientation per voxel. Connections of the red nuclei of fifteen volunteers were studied at 3T using CSD axonal tracking. We found significant connectivity between RN and the following cortical and subcortical areas: cerebellar cortex, thalamus, paracentral lobule, postcentral gyrus, precentral gyrus, superior frontal gyrus and dentate nucleus. We confirmed that red nucleus is tightly linked with the cerebral cortex and has dense subcortical connections with thalamus and cerebellar cortex. These findings may be useful in a clinical context considering that RN is involved in motor control and it is known to have potential to compensate for injury of the corticospinal tract. PMID:27181514

  1. Nucleus management in manual small incision cataract surgery by phacosection

    Directory of Open Access Journals (Sweden)

    Ravindra M

    2009-01-01

    Full Text Available Nucleus management is critical in manual small incision cataract surgery (MSICS, as the integrity of the tunnel, endothelium and posterior capsule needs to be respected. Several techniques of nucleus management are in vogue, depending upon the specific technique of MSICS. Nucleus can be removed in toto or bisected or trisected into smaller segments. The pressure in the eye can be maintained at the desired level with the use of an anterior chamber maintainer or kept at atmospheric levels. In MSICS, unlike phacoemulsification, there is no need to limit the size of the tunnel or restrain the size of capsulorrhexis. Large well-structured tunnels and larger capsulorrhexis provide better control on the surgical maneuvers. Safety and simplicity of MSICS has made it extremely popular. The purpose of this article is to describe nucleus management by phacosection in MSICS.

  2. Asymptotic properties of high-pT particle production in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions at high energies

    CERN Document Server

    Tokarev, M V

    2001-01-01

    The concept of z-scaling reflecting the general features of particle substructure, constituent interaction and mechanism of particle formation is reviewed. Experimental data on the cross sections obtained at ISR, SpS and Tevatron are used in the analysis. The properties of data z-presentation, the energy and angular independencies, the power law, A- and F-dependencies, are discussed. The use of z-scaling to search for new physics phenomena in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions is suggested. The violation of z-scaling characterized by the change of the fractal dimension is considered as a new and complimentary signature of nuclear phase transition.

  3. The role of proopiomelanocortin (POMC neurones in feeding behaviour

    Directory of Open Access Journals (Sweden)

    Millington George WM

    2007-09-01

    Full Text Available Abstract The precursor protein, proopiomelanocortin (POMC, produces many biologically active peptides via a series of enzymatic steps in a tissue-specific manner, yielding the melanocyte-stimulating hormones (MSHs, corticotrophin (ACTH and β-endorphin. The MSHs and ACTH bind to the extracellular G-protein coupled melanocortin receptors (MCRs of which there are five subtypes. The MC3R and MC4R show widespread expression in the central nervous system (CNS, whilst there is low level expression of MC1R and MC5R. In the CNS, cell bodies for POMC are mainly located in the arcuate nucleus of the hypothalamus and the nucleus tractus solitarius of the brainstem. Both of these areas have well defined functions relating to appetite and food intake. Mouse knockouts (ko for pomc, mc4r and mc3r all show an obese phenotype, as do humans expressing mutations of POMC and MC4R. Recently, human subjects with specific mutations in β-MSH have been found to be obese too, as have mice with engineered β-endorphin deficiency. The CNS POMC system has other functions, including regulation of sexual behaviour, lactation, the reproductive cycle and possibly central cardiovascular control. However, this review will focus on feeding behaviour and link it in with the neuroanatomy of the POMC neurones in the hypothalamus and brainstem.

  4. Neutral current neutrino-nucleus interactions at high energies

    CERN Document Server

    Ducati, M B Gay; Machado, M V T

    2008-01-01

    We present a QCD analysis of the neutral current neutrino-nucleus interaction at the small-x region using the color dipole formalism. This phenomenological approach is quite successful in describing experimental results in deep inelastic ep scattering and charged current neutrino-nucleus interactions at high energies. We present theoretical predictions for the relevant structure functions and the corresponding implications for the total NC neutrino cross section.

  5. Leading nucleon and the proton-nucleus inelasticity

    CERN Document Server

    Bellandi, J; Dias de Deus, J

    1999-01-01

    We present in this paper a calculation of the average proton-nucleus inelasticity. Using an Iterative Leading Particle Model and the Glauber model, we relate the leading particle distribution in nucleon-nucleus interactions with the respective one in nucleon- proton collisions. To describe the leading particle distribution in nucleon-proton collisions, we use the Regge Mueller formalism. Contribution to 26th ICRC - Salt Lake City, Utah. August, 1999. HE 1.1.14

  6. New computational methods for determining antikaon-nucleus bound states

    International Nuclear Information System (INIS)

    Optical potential for antikaon-nucleus strong interactions are constructed using elementary antikaon-nucleus potentials determined previously. The optical potentials are used to determine the existence of a kaon hypernucleus. Modern three dimensional visualization techniques are used to study model dependences, new methods for speeding the calculation of the optical potential are developed, and previous approximation to avoid full Fermi averaging are eliminated. 19 refs., 21 figs., 3 tabs

  7. Inelaticity in hadron-nucleus collisions from emulsion chamber studies

    CERN Document Server

    Wilk, G

    1999-01-01

    The inelasticity of hadron-carbon nucleus collisions in the energy region exceeding 100 TeV is estimated from the carbon-emulsion chamber data at Pamirs to be $ = 0.65\\pm 0.08$. When combined with the recently presented data on hadron-lead nucleus collisions taken at the same energy range it results in the $K\\sim A^{0.086}$ mass number dependence of inelasticity. The evaluated partial inelasticity for secondary ($\

  8. Nucleus Pearl Coating Process of Freshwater Mussel Anodonta woodiana (Unionidae)

    OpenAIRE

    WASMEN MANALU; DEDY DURYADI SOLIHIN; SATA YOSHIDA SRIE RAHAYU; RIDWAN AFFANDI

    2013-01-01

    The limiting factor which is a weakness of sea water pearl production are high costs, the risk of major business failures and a long coating time. From the issue of freshwater pearls appear to have prospects of alternative substitution for sea water pearl. This present study aimed to evaluate effect of loads (the number and diameter nucleus) on freshwater pearl coating process and the number and size of the appropriate nucleus diameter, to produce the optimum coating thickness of half-round p...

  9. Specific structure of the 6He nucleus and fragmentation experiments

    International Nuclear Information System (INIS)

    Within the framework of the microscopic α+2n model, transverse momentum distributions of α-particles and neutrons as well as α-particle - neutron momentum correlation function have been calculated for the radioactive 6He nucleus fragmentation. The results show that these momentum distributions reflect a specific structure of the 6He nucleus, i.e. the experiments on fragmentation provide with the information on 6He structure. (orig.)

  10. Shell Correction at the Saddle Point for Superheavy Nucleus

    Institute of Scientific and Technical Information of China (English)

    张炜; 张时声; 张双全; 孟杰

    2003-01-01

    The potential energy surface for superheavy nucleus has been studied within the framework of the constrained relativistic mean field theory, and the shell correction energy as a function of deformation has been extracted by the Strutinsky shell correction procedure. Contrary to the usual expectation, the shell correction energy at the saddle point is too important to be neglected, and it has essential contribution to the fission barrier in superheavy nucleus.

  11. Mechanical behavior of the human lumbar intervertebral disc with polymeric hydrogel nucleus implant: An experimental and finite element study

    Science.gov (United States)

    Joshi, Abhijeet Bhaskar

    The origin of the lower back pain is often the degenerated lumbar intervertebral disc (IVD). We are proposing replacement of the degenerated nucleus by a PVA/PVP polymeric hydrogel implant. We hypothesize that a polymeric hydrogel nucleus implant can restore the normal biomechanics of the denucleated IVD by mimicking the natural load transfer phenomenon as in case of the intact IVD. Lumbar IVDs (n = 15) were harvested from human cadavers. In the first part, specimens were tested in four different conditions for compression: Intact, bone in plug, denucleated and Implanted. Hydrogel nucleus implants were chosen to have line-to-line fit in the created nuclear cavity. In the second part, nucleus implant material (modulus) and geometric (height and diameter) parameters were varied and specimens (n = 9) were tested. Nucleus implants with line-to-line fit significantly restored (88%) the compressive stiffness of the denucleated IVD. The synergistic effect between the implant and the intact annulus resulted in the nonlinear increase in implanted IVD stiffness, where Poisson effect of the hydrogel played major role. Nucleus implant parameters were observed to have a significant effect on the compressive stiffness. All implants with modulus in the tested range restored the compressive stiffness. The undersize implants resulted in incomplete restoration while oversize implants resulted in complete restoration compared to the BI condition. Finite element models (FEM) were developed to simulate the actual test conditions and validated against the experimental results for all conditions. The annulus (defined as hyperelastic, isotropic) mainly determined the nonlinear response of the IVD. Validated FEMs predicted 120--3000 kPa as a feasible range for nucleus implant modulus. FEMs also predicted that overdiameter implant would be more effective than overheight implant in terms of stiffness restoration. Underdiameter implants, initially allowed inward deformation of the annulus and

  12. GABAergic mechanisms in the pedunculopontine tegmental nucleus of the cat promote active (REM) sleep.

    Science.gov (United States)

    Torterolo, Pablo; Morales, Francisco R; Chase, Michael H

    2002-07-19

    The pedunculopontine tegmental nucleus (PPT) has been implicated in the generation and/or maintenance of both active sleep (AS) and wakefulness (W). GABAergic neurons are present within this nucleus and recent studies have shown that these neurons are active during AS. In order to examine the role of mesopontine GABAergic processes in the generation of AS, the GABA(A) agonist muscimol and the GABA(A) antagonist bicuculline were microinjected into the PPT of chronic cats that were prepared for recording the states of sleep and wakefulness. Muscimol increased the time spent in AS by increasing the frequency and duration of AS episodes; this increase in AS was at the expense of the time spent in wakefulness. A decrease in PGO density during AS was also observed following the microinjection of muscimol. On the other hand, bicuculline decreased both AS and quiet sleep and increased the time spent in wakefulness. These data suggest that GABA acts on GABA(A) receptors within the PPT to facilitate the generation of AS by suppressing the activity of waking-related processes within this nucleus. PMID:12106660

  13. beta-catenin can be transported into the nucleus in a Ran-unassisted manner.

    Science.gov (United States)

    Yokoya, F; Imamoto, N; Tachibana, T; Yoneda, Y

    1999-04-01

    The nuclear accumulation of beta-catenin plays an important role in the Wingless/Wnt signaling pathway. This study describes an examination of the nuclear import of beta-catenin in living mammalian cells and in vitro semi-intact cells. When injected into the cell cytoplasm, beta-catenin rapidly migrated into the nucleus in a temperature-dependent and wheat germ agglutinin-sensitive manner. In the cell-free import assay, beta-catenin rapidly migrates into the nucleus without the exogenous addition of cytosol, Ran, or ATP/GTP. Cytoplasmic injection of mutant Ran defective in its GTP hydrolysis did not prevent beta-catenin import. Studies using tsBN2, a temperature-sensitive mutant cell line that possesses a point mutation in the RCC1 gene, showed that the import of beta-catenin is insensitive to nuclear Ran-GTP depletion. These results show that beta-catenin possesses the ability to constitutively translocate through the nuclear pores in a manner similar to importin beta in a Ran-unassisted manner. We further showed that beta-catenin also rapidly exits the nucleus in homokaryons, suggesting that the regulation of nuclear levels of beta-catenin involves both nuclear import and export of this molecule.

  14. Electrotonic signals along intracellular membranes may interconnect dendritic spines and nucleus.

    Directory of Open Access Journals (Sweden)

    Isaac Shemer

    2008-03-01

    Full Text Available Synapses on dendritic spines of pyramidal neurons show a remarkable ability to induce phosphorylation of transcription factors at the nuclear level with a short latency, incompatible with a diffusion process from the dendritic spines to the nucleus. To account for these findings, we formulated a novel extension of the classical cable theory by considering the fact that the endoplasmic reticulum (ER is an effective charge separator, forming an intrinsic compartment that extends from the spine to the nuclear membrane. We use realistic parameters to show that an electrotonic signal may be transmitted along the ER from the dendritic spines to the nucleus. We found that this type of signal transduction can additionally account for the remarkable ability of the cell nucleus to differentiate between depolarizing synaptic signals that originate from the dendritic spines and back-propagating action potentials. This study considers a novel computational role for dendritic spines, and sheds new light on how spines and ER may jointly create an additional level of processing within the single neuron.

  15. Computational prediction of strain-dependent diffusion of transcription factors through the cell nucleus.

    Science.gov (United States)

    Nava, Michele M; Fedele, Roberto; Raimondi, Manuela T

    2016-08-01

    Nuclear spreading plays a crucial role in stem cell fate determination. In previous works, we reported evidence of multipotency maintenance for mesenchymal stromal cells cultured on three-dimensional engineered niche substrates, fabricated via two-photon laser polymerization. We correlated maintenance of multipotency to a more roundish morphology of these cells with respect to those cultured on conventional flat substrates. To interpret these findings, here we present a multiphysics model coupling nuclear strains induced by cell adhesion to passive diffusion across the cell nucleus. Fully three-dimensional reconstructions of cultured cells were developed on the basis of confocal images: in particular, the level of nuclear spreading resulted significantly dependent on the cell localization within the niche architecture. We assumed that the cell diffusivity varies as a function of the local volumetric strain. The model predictions indicate that the higher the level of spreading of the cell, the higher the flux across the nucleus of small solutes such as transcription factors. Our results point toward nuclear spreading as a primary mechanism by which the stem cell translates its shape into a fate decision, i.e., by amplifying the diffusive flow of transcriptional activators into the nucleus. PMID:26476736

  16. Estradiol in the Preoptic Area Regulates the Dopaminergic Response to Cocaine in the Nucleus Accumbens.

    Science.gov (United States)

    Tobiansky, Daniel J; Will, Ryan G; Lominac, Kevin D; Turner, Jonathan M; Hattori, Tomoko; Krishnan, Krittika; Martz, Julia R; Nutsch, Victoria L; Dominguez, Juan M

    2016-06-01

    The sex-steroid hormone estradiol (E2) enhances the psychoactive effects of cocaine, as evidenced by clinical and preclinical studies. The medial preoptic area (mPOA), a region in the hypothalamus, is a primary neural locus for neuroendocrine integration, containing one of the richest concentrations of estrogen receptors in the CNS and also has a key role in the regulation of naturally rewarding behaviors. However, whether estradiol enhances the neurochemical response to cocaine by acting in the mPOA is still unclear. Using neurotoxic lesions and microdialysis, we examined whether the mPOA modulates cocaine-induced neurochemical activity in the nucleus accumbens. Tract tracing and immunohistochemical staining were used to determine whether projections from the mPOA to the ventral tegmental area (VTA) are sensitive to estrogen signaling. Finally, estradiol microinjections followed by microdialysis were used to determine whether estrogenic signaling in the mPOA modulates cocaine-induced changes of dopamine in the nucleus accumbens. Results showed that lesions of the mPOA or microinjections of estradiol directly into the mPOA increased cocaine-induced release of dopamine in the nucleus accumbens. Immunohistochemical analyses revealed that the mPOA modulates cocaine responsiveness via projections to both dopaminergic and GABAergic neurons in the VTA, and that these projections are sensitive to estrogenic stimulation. Taken together, these findings point to a novel estradiol-dependent pathway that modulates cocaine-induced neurochemical activity in the mesolimbic system. PMID:26647972

  17. Research progress on role of ghrelin in brain%Ghrelin在脑内的效应研究进展

    Institute of Scientific and Technical Information of China (English)

    路静; 史利根; 包爱民

    2012-01-01

    脑肠肽Ghrelin(又名胃饥饿素)是生长激素促分泌激素受体的内源性配体,在外周主要由胃底细胞产生,通过刺激食欲而调节能量代谢.在脑内,Ghrelin主要在垂体和下丘脑弓状核内产生,对下丘脑内摄食、生殖、应激反应相关神经肽的合成和分泌起重要调节作用.近年来,较多的研究聚焦于Ghrelin在调节脑内学习、记忆、情绪等高级功能方面的作用,揭示了Ghrelin抗神经元凋亡,提高认知功能,调节神经内分泌轴,例如下丘脑-垂体-肾上腺轴、下丘脑-垂体-性腺轴活性而参与应激反应等显著效应.Ghrelin还极有可能在一些神经精神疾病的发病机制中扮演重要角色,因此有广阔的研究前景.文中将就相关研究进展作一综述,旨在推动对于Ghrelin在脑内的效应的研究.%The brain-gut peptide ghrelin,a endogenous ligand for the growth hormone secretagogue hormone receptor,is mainly produced by gastric cells in the periphery,regulating energy metabolism via stimulating the appetite. Inside the brain, ghrelin is mainly expressed in the pituitary and in the hypothalamic arcuate nucleus, regulating the synthesis and secretion of neuropeptides that are correlated with feeding behavior, reproduction, and stress responses. Recently, more and more researches focused on the regulating roles of ghrelin on learning and memory, and mood regulation have indicated that ghrelin may inhibit neuronal apoptosis, improve cognitive function, and regulate the activities of neuroendocrine systems such as the hypothalamo-pituitary-adrenal axis and the hypothalamo-pituitary-gonadal axis thus get involved in the pathogenesis of neuropsychiatric diseases. The aim of this review is to summarize the main findings in this field,with the purpose of promoting further studies on the role of ghrelin in the brain.

  18. A Universal Description of Pseudorapidity Distributions in Both Nucleus-Nucleus and p-p Collisions at Currently Available Energies

    Directory of Open Access Journals (Sweden)

    Z. J. Jiang

    2016-01-01

    Full Text Available Investigations have shown that the collective motion appears not only in nucleus-nucleus but also in p-p collisions. The best tool for depicting such collective motion is relativistic hydrodynamics. In this paper, the collective motion is assumed to obey the hydrodynamic model which integrates the features of Landau and Hwa-Bjorken theory and is one of a very few analytically solvable models. The fluid is then supposed to freeze out into charged particles from a space-like hypersurface with a fixed time of tFO. The investigations of present paper show that this part of charged particles together with leading particles, which, by conventional definition, carry on the quantum numbers of colliding nucleons and take away the most part of incident energy, can give a proper universal description to the pseudorapidity distributions of charged particles measured in both nucleus-nucleus and p-p collisions at currently available energies.

  19. Pedunculopontine Nucleus Gamma Band Activity-Preconscious Awareness, Waking, and REM Sleep

    Directory of Open Access Journals (Sweden)

    Francisco J Urbano

    2014-10-01

    Full Text Available The pedunculopontine nucleus (PPN is a major component of the reticular activating system (RAS that regulates waking and REM sleep, states of high frequency EEG activity. Recently, we described the presence of high threshold, voltage-dependent N- and P/Q-type calcium channels in RAS nuclei that subserve gamma band oscillations in the mesopontine pedunculopontine nucleus (PPN, intralaminar parafascicular nucleus (Pf, and pontine Subcoeruleus nucleus dorsalis (SubCD. Cortical gamma band activity participates in sensory perception, problem solving, and memory. Rather than participating in the temporal binding of sensory events as in the cortex, gamma band activity in the RAS may participate in the processes of preconscious awareness, and provide the essential stream of information for the formulation of many of our actions. That is, the RAS may play an early permissive role in volition. Our latest results suggest that, 1 the manifestation of gamma band activity during waking may employ a separate intracellular pathway compared to that during REM sleep, 2 neuronal calcium sensor (NCS-1 protein, which is over expressed in schizophrenia and bipolar disorder, modulates gamma band oscillations in the PPN in a concentration-dependent manner, 3 leptin, which undergoes resistance in obesity resulting in sleep dysregulation, decreases sodium currents in PPN neurons, accounting for its normal attenuation of waking, and 4 following our discovery of electrical coupling in the RAS, we hypothesize that there are cell clusters within the PPN that may act in concert. These results provide novel information on the mechanisms controlling high frequency activity related to waking and REM sleep by elements of the RAS.

  20. ELECTROPHYSIOLOGICAL PROPERTIES OF MORPHOLOGICALLY-IDENTIFIED MEDIAL VESTIBULAR NUCLEUS NEURONS PROJECTING TO THE ABDUCENS NUCLEUS IN THE CHICK EMBRYO

    OpenAIRE

    Gottesman-Davis, Adria; Shao, Mei; Hirsch, June C.; Peusner, Kenna D.

    2010-01-01

    Neurons in the medial vestibular nucleus (MVN) show a wide range of axonal projection pathways, intrinsic firing properties, and responses to head movements. To determine whether MVN neurons participating in the vestibulocular reflexes (VOR) have distinctive electrophysiological properties related to their output pathways, a new preparation was devised using transverse brain slices containing the chicken MVN and abducens nucleus. Biocytin Alexa Fluor was injected extracellularly into the abdu...

  1. The deafferented reticular thalamic nucleus generates spindle rhythmicity.

    Science.gov (United States)

    Steriade, M; Domich, L; Oakson, G; Deschênes, M

    1987-01-01

    The hypothesis that nucleus reticularis thalami (RE) is the generator of spindle rhythmicity during electroencephalogram (EEG) synchronization was tested in acutely prepared cats. Unit discharges and focal waves were extracellularly recorded in the rostral pole of RE nucleus, which was completely disconnected by transections from all other thalamic nuclei. In some experiments, additional transections through corona radiata created a triangular island in which the rostral RE pole survived with the caudate nucleus, putamen, basal forebrain nuclei, prepyriform area, and the adjacent cortex. Similar results were obtained in two types of experiments: brain stem-transected preparations that exhibited spontaneous spindle sequences, and animals under ketamine anesthesia in which transient spindling was repeatedly precipitated during recording by very low doses of a short-acting barbiturate. Both spindle-related rhythms (7- to 16-Hz waves grouped in sequences that recur with a rhythm of 0.1-0.3 Hz) are seen in focal recordings of the deafferented RE nucleus. The presence of spindling rhythmicity in the disconnected RE nucleus contrasts with total absence of spindles in cortical EEG leads and in thalamic recordings behind the transection. Oscillations within the same frequency range as that of spontaneous spindles can be evoked in the deafferented RE nucleus by subcortical white matter stimulation. In deafferented RE cells, the burst structure consists of an initially biphasic acceleration-deceleration pattern, eventually leading to a long-lasting tonic tail. Quantitative group data show that the burst parameters of disconnected RE cells are very similar to those of RE neurons with intact connections. In the deafferented RE nucleus, spike bursts of RE neurons recur periodically (0.1-0.3 Hz) in close time-relation with simultaneously recorded focal spindle sequences. The burst occurrence of deafferented RE cells is greatly reduced after systemic administration of bicuculline

  2. Fluctuations and correlations in nucleus-nucleus collisions within transport approaches

    Energy Technology Data Exchange (ETDEWEB)

    Konchakovski, Volodymyr P.

    2009-10-01

    The current thesis is devoted to a systematic study of fluctuations and correlations in heavy-ion collisions, which might be considered as probes for the phase transition and the critical point in the phase diagram, within the Hadron-String- Dynamics (HSD) microscopic transport approach. This is a powerful tool to study nucleus-nucleus collisions and allows to completely simulate experimental collisions on an event-by-event basis. Thus, the transport model has been used to study fluctuations and correlations including the influence of experimental acceptance as well as centrality, system size and collision energy. The comparison to experimental data can separate the effects induced by a phase transition since there is no phase transition in the HSD version used here. Firstly the centrality dependence of multiplicity fluctuations has been studied. Different centrality selections have been performed in the analysis in correspondence to the experimental situation. For the fixed target experiment NA49 events with fixed numbers of the projectile participants have been studied while in the collider experiment PHENIX centrality classes of events have been defined by the multiplicity in certain phase space region. A decrease of participant number fluctuations (and thus volume fluctuations) in more central collisions for both experiments has been obtained. Another area of this work addresses to transport model calculations of multiplicity fluctuations in nucleus-nucleus collisions as a function of colliding energy and system size. This study is in full correspondence to the experimental program of the NA61 Collaboration at the SPS. Central C+C, S+S, In+In, and Pb+Pb nuclear collisions at Elab = 10, 20, 30, 40, 80, 158 AGeV have been investigated. The expected enhanced fluctuations - attributed to the critical point and phase transition - can be observed experimentally on top of a monotonic and smooth 'hadronic background'. These findings should be helpful for the

  3. Fluctuations and correlations in nucleus-nucleus collisions within transport approaches

    International Nuclear Information System (INIS)

    The current thesis is devoted to a systematic study of fluctuations and correlations in heavy-ion collisions, which might be considered as probes for the phase transition and the critical point in the phase diagram, within the Hadron-String- Dynamics (HSD) microscopic transport approach. This is a powerful tool to study nucleus-nucleus collisions and allows to completely simulate experimental collisions on an event-by-event basis. Thus, the transport model has been used to study fluctuations and correlations including the influence of experimental acceptance as well as centrality, system size and collision energy. The comparison to experimental data can separate the effects induced by a phase transition since there is no phase transition in the HSD version used here. Firstly the centrality dependence of multiplicity fluctuations has been studied. Different centrality selections have been performed in the analysis in correspondence to the experimental situation. For the fixed target experiment NA49 events with fixed numbers of the projectile participants have been studied while in the collider experiment PHENIX centrality classes of events have been defined by the multiplicity in certain phase space region. A decrease of participant number fluctuations (and thus volume fluctuations) in more central collisions for both experiments has been obtained. Another area of this work addresses to transport model calculations of multiplicity fluctuations in nucleus-nucleus collisions as a function of colliding energy and system size. This study is in full correspondence to the experimental program of the NA61 Collaboration at the SPS. Central C+C, S+S, In+In, and Pb+Pb nuclear collisions at Elab = 10, 20, 30, 40, 80, 158 AGeV have been investigated. The expected enhanced fluctuations - attributed to the critical point and phase transition - can be observed experimentally on top of a monotonic and smooth 'hadronic background'. These findings should be helpful for the optimal

  4. The small GTPase RhoA localizes to the nucleus and is activated by Net1 and DNA damage signals.

    Directory of Open Access Journals (Sweden)

    Adi D Dubash

    Full Text Available BACKGROUND: Rho GTPases control many cellular processes, including cell survival, gene expression and migration. Rho proteins reside mainly in the cytosol and are targeted to the plasma membrane (PM upon specific activation by guanine nucleotide exchange factors (GEFs. Accordingly, most GEFs are also cytosolic or associated with the PM. However, Net1, a RhoA-specific GEF predominantly localizes to the cell nucleus at steady-state. Nuclear localization for Net1 has been seen as a mechanism for sequestering the GEF away from RhoA, effectively rendering the protein inactive. However, considering the prominence of nuclear Net1 and the fact that a biological stimulus that promotes Net1 translocation out the nucleus to the cytosol has yet to be discovered, we hypothesized that Net1 might have a previously unidentified function in the nucleus of cells. PRINCIPAL FINDINGS: Using an affinity precipitation method to pulldown the active form of Rho GEFs from different cellular fractions, we show here that nuclear Net1 does in fact exist in an active form, contrary to previous expectations. We further demonstrate that a fraction of RhoA resides in the nucleus, and can also be found in a GTP-bound active form and that Net1 plays a role in the activation of nuclear RhoA. In addition, we show that ionizing radiation (IR specifically promotes the activation of the nuclear pool of RhoA in a Net1-dependent manner, while the cytoplasmic activity remains unchanged. Surprisingly, irradiating isolated nuclei alone also increases nuclear RhoA activity via Net1, suggesting that all the signals required for IR-induced nuclear RhoA signaling are contained within the nucleus. CONCLUSIONS/SIGNIFICANCE: These results demonstrate the existence of a functional Net1/RhoA signaling pathway within the nucleus of the cell and implicate them in the DNA damage response.

  5. Atmospheric Aerosols: Cloud Condensation Nucleus Activity of Selected Organic Molecules

    Science.gov (United States)

    Rosenorn, T.; Henning, S.; Hartz, K. H.; Kiss, G.; Pandis, S.; Bilde, M.

    2005-12-01

    Gas/particle partitioning of vapors in the atmosphere plays a major role in both climate through micro meteorology and in the physical and chemical processes of a single particle. This work has focused on the cloud droplet activation of a number of pure and mixed compounds. The means used to investigate these processes have been the University of Copenhagen cloud condensation nucleus counter setup and the Carnegie Mellon University CCNC setup. The importance of correct water activity modeling has been addressed and it has been pointed out that the molecular mass is an important parameter to consider when choosing model compounds for cloud activation models. It was shown that both traditional Kohler theory and Kohler theory modified to account for limited solubility reproduce measurements of soluble compounds well. For less soluble compounds it is necessary to use Kohler theory modified to account for limited solubility. It was also shown that this works for mixtures of compounds containing both inorganic salts and dicarboxylic acids. It has also been shown that particle phase and humidity history is important for activation behavior of particles consisting of two slightly soluble organic substances (succinic and adipic acid) and a soluble salt (NaCl). Model parameters for terpene oxidation product cloud activation have been derived. These are based on two sets of average parameters covering monoterpene oxidation products and sesquiterpene oxidation products. All parameters except the solubility were estimated and an effective solubility was calculated as the fitting parameter. The average solubility of the model compound found for mono terpene oxidation products is similar to those of sodium chloride and ammonium sulfate; however the higher molecular weight leads to a slightly higher activation diameter at fixed supersaturation. On a molar basis the monoterpene oxidation products show a 1.5 times higher effective solubility than the sesquiterpene oxidation products.

  6. Histone arginine methylation in cocaine action in the nucleus accumbens.

    Science.gov (United States)

    Damez-Werno, Diane M; Sun, HaoSheng; Scobie, Kimberly N; Shao, Ningyi; Rabkin, Jaclyn; Dias, Caroline; Calipari, Erin S; Maze, Ian; Pena, Catherine J; Walker, Deena M; Cahill, Michael E; Chandra, Ramesh; Gancarz, Amy; Mouzon, Ezekiell; Landry, Joseph A; Cates, Hannah; Lobo, Mary-Kay; Dietz, David; Allis, C David; Guccione, Ernesto; Turecki, Gustavo; Defilippi, Paola; Neve, Rachael L; Hurd, Yasmin L; Shen, Li; Nestler, Eric J

    2016-08-23

    Repeated cocaine exposure regulates transcriptional regulation within the nucleus accumbens (NAc), and epigenetic mechanisms-such as histone acetylation and methylation on Lys residues-have been linked to these lasting actions of cocaine. In contrast to Lys methylation, the role of histone Arg (R) methylation remains underexplored in addiction models. Here we show that protein-R-methyltransferase-6 (PRMT6) and its associated histone mark, asymmetric dimethylation of R2 on histone H3 (H3R2me2a), are decreased in the NAc of mice and rats after repeated cocaine exposure, including self-administration, and in the NAc of cocaine-addicted humans. Such PRMT6 down-regulation occurs selectively in NAc medium spiny neurons (MSNs) expressing dopamine D2 receptors (D2-MSNs), with opposite regulation occurring in D1-MSNs, and serves to protect against cocaine-induced addictive-like behavioral abnormalities. Using ChIP-seq, we identified Src kinase signaling inhibitor 1 (Srcin1; also referred to as p140Cap) as a key gene target for reduced H3R2me2a binding, and found that consequent Srcin1 induction in the NAc decreases Src signaling, cocaine reward, and the motivation to self-administer cocaine. Taken together, these findings suggest that suppression of Src signaling in NAc D2-MSNs, via PRMT6 and H3R2me2a down-regulation, functions as a homeostatic brake to restrain cocaine action, and provide novel candidates for the development of treatments for cocaine addiction. PMID:27506785

  7. Characterization of cap binding proteins associated with the nucleus

    International Nuclear Information System (INIS)

    Eucaryotic mRNAs a carry 7-methylguanosine triphosphate residue (called cap structure) at their 5' terminus. The cap plays an important role in RNA recognition. Cap binding proteins (CBP) of HeLa cells were identified by photoaffinity labelling using the cap analogue γ-(32P)-(4-(benzoyl-phenyl)methylamido)-7-methylguanosine-5'-triphosphate (BP-m7GTP). Photoreaction of this cap analogue with HeLa cell initiation factors resulted in specific labelling of two polypeptides of Msub(r) 37000 and 26000. The latter was also labelled in crude initiation factors prepared from reticulocytes and is identical to the cap binding protein CBP I previously identified. These cap binding proteins were also affinity labelled in poliovirus infected cell extracts. Photoaffinity reaction with BP-m7GTP of whole HeLa cell homogenate showed three additional polypeptides with Msub(r) 120000, 89000 and 80000. These cap binding proteins were found to be associated with the nucleus and are therefore referred to as nuclear cap binding proteins, i.e. NCBP 1, NCBP 2 and NCBP 3. They were also present in splicing extracts. Photoaffinity labelling in these nuclear extracts was differentially inhibited by various cap analogues and capped mRNAs. Affinity chromatography on immobilized globin mRNA led to a partial separation of the three nuclear cap binding proteins. Chromatography on m7GTP-Sepharose resulted in a specific binding of NCBP 3. The different behaviour of the cap binding proteins suggests that they are functionally distinct and that they might be involved in different processes requiring cap recognition. (Author)

  8. PREFACE: 11th International Conference on Nucleus-Nucleus Collisions (NN2012)

    Science.gov (United States)

    Li, Bao-An; Natowitz, Joseph B.

    2013-03-01

    The 11th International Conference on Nucleus-Nucleus Collisions (NN2012) was held from 27 May to 1 June 2012, in San Antonio, Texas, USA. It was jointly organized and hosted by The Cyclotron Institute at Texas A&M University, College Station and The Department of Physics and Astronomy at Texas A&M University-Commerce. Among the approximately 300 participants were a large number of graduate students and post-doctoral fellows. The Keynote Talk of the conference, 'The State of Affairs of Present and Future Nucleus-Nucleus Collision Science', was given by Dr Robert Tribble, University Distinguished Professor and Director of the TAMU Cyclotron Institute. During the conference a very well-received public lecture on neutrino astronomy, 'The ICEcube project', was given by Dr Francis Halzen, Hilldale and Gregory Breit Distinguished Professor at the University of Wisconsin, Madison. The Scientific program continued in the general spirit and intention of this conference series. As is typical of this conference a broad range of topics including fundamental areas of nuclear dynamics, structure, and applications were addressed in 42 plenary session talks, 150 parallel session talks, and 21 posters. The high quality of the work presented emphasized the vitality and relevance of the subject matter of this conference. Following the tradition, the NN2012 International Advisory Committee selected the host and site of the next conference in this series. The 12th International Conference on Nucleus-Nucleus Collisions (NN2015) will be held 21-26 June 2015 in Catania, Italy. It will be hosted by The INFN, Laboratori Nazionali del Sud, INFN, Catania and the Dipartimento di Fisica e Astronomia of the University of Catania. The NN2012 Proceedings contains the conference program and 165 articles organized into the following 10 sections 1. Heavy and Superheavy Elements 2. QCD and Hadron Physics 3. Relativistic Heavy-Ion Collisions 4. Nuclear Structure 5. Nuclear Energy and Applications of

  9. Quinoxaline Nucleus: A Promising Scaffold in Anti-cancer Drug Discovery.

    Science.gov (United States)

    Pinheiro, Alessandra C; Mendonça Nogueira, Thais C; de Souza, Marcus V N

    2016-01-01

    Heterocyclic compounds are a class of substances, which play a critical role in modern drug discovery being incorporated in the structure of a large variety of drugs used in many different types of diseases. Quinoxaline is an important heterocyclic nucleus with a wide spectrum of biological activities, and recently much attention has been found on anticancer drug discovery based on this class. Owing to the importance of this system, the aim of this review is to provide an update on the synthesis and anticancer activity of quinoxaline derivatives covering articles published between 2010 and 2015.

  10. Recent Results of the Relativistic Green's Function Model in Quasielastic Neutrino and Antineutrino-Nucleus Scattering

    CERN Document Server

    Giusti, Carlotta

    2014-01-01

    The analysis of quasielastic neutrino and antineutrino-nucleus scattering cross sections requires relativistic theoretical descriptions also accounting for the role of final-state interactions (FSI). In the relativistic Green's function (RGF) model FSI are described by a complex optical potential where the imaginary part recovers the contribution of final-state channels that are not included in other models based on the impulse approximation. The RGF results are compared with the data recently published by the MiniBooNE and MINER$\

  11. Perturbation of nucleo-cytoplasmic transport affects size of nucleus and nucleolus in human cells.

    Science.gov (United States)

    Ganguly, Abira; Bhattacharjee, Chumki; Bhave, Madhura; Kailaje, Vaishali; Jain, Bhawik K; Sengupta, Isha; Rangarajan, Annapoorni; Bhattacharyya, Dibyendu

    2016-03-01

    Size regulation of human cell nucleus and nucleolus are poorly understood subjects. 3D reconstruction of live image shows that the karyoplasmic ratio (KR) increases by 30-80% in transformed cell lines compared to their immortalized counterpart. The attenuation of nucleo-cytoplasmic transport causes the KR value to increase by 30-50% in immortalized cell lines. Nucleolus volumes are significantly increased in transformed cell lines and the attenuation of nucleo-cytoplasmic transport causes a significant increase in the nucleolus volume of immortalized cell lines. A cytosol and nuclear fraction swapping experiment emphasizes the potential role of unknown cytosolic factors in nuclear and nucleolar size regulation.

  12. Experimentally induced postinhibitory rebound in rat nucleus ambiguus is dependent on hyperpolarization parameters and membrane potential.

    Science.gov (United States)

    Dean, J B; Czyzyk-Krzeska, M; Millhorn, D E

    1989-06-01

    Postinhibitory rebound (PIR), a transient depolarization subsequent to release from experimental hyperpolarization, was identified and characterized in 81% of the cells studied in the nucleus ambiguus in slices from medulla of rat. Hyperpolarizing current pulses were administered via the recording microelectrode in the bridge-balanced mode to test for PIR. The voltage trajectory was characterized by a depolarizing sag during the pulse, rebound depolarization (PIR) after the pulse and increased input resistance during rebound. The amplitude and time course of PIR were dependent on prepulse membrane potential, pulse amplitude and pulse duration. These results suggest a potential role of PIR in respiratory rhythmogenesis. PMID:2771207

  13. Effect of acupuncture on adrenocortical hormone production in rabbits with a central lesion

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Y.Y.; Seto, K.; Saitoh, H.; Kawakami, M.

    A study was made of adrenocortical hormone production under electroacupuncture stimulation of the Tsu-San-Li locus in rabbits with a lesion in the fornix, stria terminalis, ventromedial nucleus or arcuate nucleus. In rabbits with a lesion in the stria terminalis or ventromedial nucleus, electroacupuncture stimulation of Tsu-San-Li resulted in no increase in phase 1 but an increase in phase 2 of adrenocortical hormone production. In rabbits with a lesion in the fornix or arcuate nucleus electroacupuncture stimulation of Tsu-San-Li was followed by increased adrenocortical hormone production in the both phases. These results show that the stria terminalis and the ventromedial nucleus play a major role in the augmentation of adrenocortical hormone production by electroacupuncture stimulation of Tsu-San-Li.

  14. Nucleus Pearl Coating Process of Freshwater Mussel Anodonta woodiana (Unionidae

    Directory of Open Access Journals (Sweden)

    WASMEN MANALU

    2013-03-01

    Full Text Available The limiting factor which is a weakness of sea water pearl production are high costs, the risk of major business failures and a long coating time. From the issue of freshwater pearls appear to have prospects of alternative substitution for sea water pearl. This present study aimed to evaluate effect of loads (the number and diameter nucleus on freshwater pearl coating process and the number and size of the appropriate nucleus diameter, to produce the optimum coating thickness of half-round pearls. The research consists of experimental implantation of 2, 4, and 6 nucleus number per individual mussel was maintained by the method stocked in hapa in bottom waters. Observation method and factorial randomized block design used in the study of the influence of the load to the successfulness of pearl coating and the pearl layer thickness. The results showed that A. woodiana can be utilized as a producer of freshwater pearls. In addition, the number of optimum nucleus that can be attached to the mussel A. woodiana was 2 grains/individuals with a diameter of 10 mm. Shells implanted with the optimum nucleus diameter and number of pearls produced the highest layer thickness of 17 m after 9 months cultivation. This result was good enough compared with the layer thickness of sea water pearl production after the same cultivation time.

  15. Endogenous GLP-1 acts on paraventricular nucleus to suppress feeding: projection from nucleus tractus solitarius and activation of corticotropin-releasing hormone, nesfatin-1 and oxytocin neurons.

    Science.gov (United States)

    Katsurada, Kenichi; Maejima, Yuko; Nakata, Masanori; Kodaira, Misato; Suyama, Shigetomo; Iwasaki, Yusaku; Kario, Kazuomi; Yada, Toshihiko

    2014-08-22

    Glucagon-like peptide-1 (GLP-1) receptor agonists have been used to treat type 2 diabetic patients and shown to reduce food intake and body weight. The anorexigenic effects of GLP-1 and GLP-1 receptor agonists are thought to be mediated primarily via the hypothalamic paraventricular nucleus (PVN). GLP-1, an intestinal hormone, is also localized in the nucleus tractus solitarius (NTS) of the brain stem. However, the role of endogenous GLP-1, particularly that in the NTS neurons, in feeding regulation remains to be established. The present study examined whether the NTS GLP-1 neurons project to PVN and whether the endogenous GLP-1 acts on PVN to restrict feeding. Intra-PVN injection of GLP-1 receptor antagonist exendin (9-39) increased food intake. Injection of retrograde tracer into PVN combined with immunohistochemistry for GLP-1 in NTS revealed direct projection of NTS GLP-1 neurons to PVN. Moreover, GLP-1 evoked Ca(2+) signaling in single neurons isolated from PVN. The majority of GLP-1-responsive neurons were immunoreactive predominantly to corticotropin-releasing hormone (CRH) and nesfatin-1, and less frequently to oxytocin. These results indicate that endogenous GLP-1 targets PVN to restrict feeding behavior, in which the projection from NTS GLP-1 neurons and activation of CRH and nesfatin-1 neurons might be implicated. This study reveals a neuronal basis for the anorexigenic effect of endogenous GLP-1 in the brain.

  16. Effects of Electrolytic Lesions of the Ventrolateral Periaqueductal Gray and Nucleus Raphe Magnus on Morphine – Induced Antinociception in the Nucleus Cuneiformi

    Directory of Open Access Journals (Sweden)

    Abbas Haghparast

    2010-08-01

    Full Text Available A B S T R A C TIntroduction: The nucleus cuneiformis (NCF and ventrolateral periaqueductal gray (vlPAG, two adjacent areas, mediate the central pain modulation and project to the nucleus raphe magnus (NRM. Methods: This study examined whether the antinociceptive effect of morphine microinjected into the NCF is influenced by inactivation of vlPAG and NRM in rats. Animals were bilaterally microinjected with morphine (2.5 µg/0.3 µl saline into the NCF. Electrolytic lesions were made in vlPAG (0.1 mA, 45 sec and/or NRM (1 mA, 30 sec. Tail-flick latency (TFL was measured at 30, 60, 90 and 120 min after microinjection. Results: The results showed that TFLs are significantly decreased in vlPAG+NRM lesions group at 30 (P<0.001 and 60 (P<0.01 min after intra- NCF administration of morphine whereas TFLs did not affect in solely vlPAG lesion animals. Our findings show that concurrent lesions of NRM and vlPAG completely reversed the analgesic effect of morphine in NCF. However, vlPAG do not play a critical role directly in pain modulatory system elicited from NCF, at least at the level of morphine-induced analgesia. Discussion: It can be concluded that its interactive effect in descending pain modulation from NCF to NRM should not be neglected.

  17. Rat nucleus accumbens core astrocytes modulate reward and the motivation to self-administer ethanol after abstinence.

    Science.gov (United States)

    Bull, Cecilia; Freitas, Kelen C C; Zou, Shiping; Poland, Ryan S; Syed, Wahab A; Urban, Daniel J; Minter, Sabrina C; Shelton, Keith L; Hauser, Kurt F; Negus, S Stevens; Knapp, Pamela E; Bowers, M Scott

    2014-11-01

    Our understanding of the active role that astrocytes play in modulating neuronal function and behavior is rapidly expanding, but little is known about the role that astrocytes may play in drug-seeking behavior for commonly abused substances. Given that the nucleus accumbens is critically involved in substance abuse and motivation, we sought to determine whether nucleus accumbens astrocytes influence the motivation to self-administer ethanol following abstinence. We found that the packing density of astrocytes that were expressing glial fibrillary acidic protein increased in the nucleus accumbens core (NAcore) during abstinence from EtOH self-administration. No change was observed in the nucleus accumbens shell. This increased NAcore astrocyte density positively correlated with the motivation for ethanol. Astrocytes can communicate with one another and influence neuronal activity through gap-junction hemichannels. Because of this, the effect of blocking gap-junction hemichannels on the motivation for ethanol was examined. The motivation to self-administer ethanol after 3 weeks abstinence was increased following microinjection of gap-junction hemichannel blockers into the NAcore at doses that block both neuronal and astrocytic channels. In contrast, no effect was observed following microinjection of doses that are not thought to block astrocytic channels or following microinjection of either dose into the nucleus accumbens shell. Additionally, the motivation for sucrose after 3 weeks abstinence was unaffected by NAcore gap-junction hemichannel blockers. Next, Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) were selectively expressed in NAcore astrocytes to test the effect of astrocyte stimulation. DREADD activation increased cytosolic calcium in primary astrocytes, facilitated responding for rewarding brain stimulation, and reduced the motivation for ethanol after 3 weeks abstinence. This is the first work to modulate drug-seeking behavior with

  18. Identification of novel light-induced genes in the suprachiasmatic nucleus

    Directory of Open Access Journals (Sweden)

    Piontkivska Helen

    2007-11-01

    Full Text Available Abstract Background The transmission of information about the photic environment to the circadian clock involves a complex array of neurotransmitters, receptors, and second messenger systems. Exposure of an animal to light during the subjective night initiates rapid transcription of a number of immediate-early genes in the suprachiasmatic nucleus of the hypothalamus. Some of these genes have known roles in entraining the circadian clock, while others have unknown functions. Using laser capture microscopy, microarray analysis, and quantitative real-time PCR, we performed a comprehensive screen for changes in gene expression immediately following a 30 minute light pulse in suprachiasmatic nucleus of mice. Results The results of the microarray screen successfully identified previously known light-induced genes as well as several novel genes that may be important in the circadian clock. Newly identified light-induced genes include early growth response 2, proviral integration site 3, growth-arrest and DNA-damage-inducible 45 beta, and TCDD-inducible poly(ADP-ribose polymerase. Comparative analysis of promoter sequences revealed the presence of evolutionarily conserved CRE and associated TATA box elements in most of the light-induced genes, while other core clock genes generally lack this combination of promoter elements. Conclusion The photic signalling cascade in the suprachiasmatic nucleus activates an array of immediate-early genes, most of which have unknown functions in the circadian clock. Detected evolutionary conservation of CRE and TATA box elements in promoters of light-induced genes suggest that the functional role of these elements has likely remained the same over evolutionary time across mammalian orders.

  19. Optimal reactions for the synthesis of superheavy nucleus 270Hs

    Institute of Scientific and Technical Information of China (English)

    LIU Zuhua; BAO Jingdong

    2006-01-01

    The superheavy nucleus 270 Hs iS expected to be a "double-magic" deformed nucleus.We have calculated its cross sections of evaporation residue for the reactions 248Cm(26Mg,4n)270Hs,244pu(30Si,4n)270Hs,238U(36S,4n)270Hs and 226Ra(48Ca,4n)270Hs using a two-parameter Smoluchowski equation.It is found from our results that 226Ra(48Ca,4n)270Hs and 238U(36S,4n)270Hs are two optimal reactions for the synthesis of the superheavy nucleus 270Hs due to their large negative Q-values.

  20. Microinjection of limonene into caudate nucleus inhibits IMC of rats

    Institute of Scientific and Technical Information of China (English)

    Hong Guo; Xin Yi Zhu; Yi Quan Wei; De Zhi Yang

    2000-01-01

    AIM We have discovered that Limonene modulates interdigestive myoelectrical complexes (IMCs) ofgastrointestinal tract in rats. In this research we will elucidate weather limonene affects acetylcholine M-receptor in caudate nucleus.METHODS Changes of IMCs were studied after limonene and/or atropine were microinjected into caudatenucleus. IMCs were recorded by a RM-6200 four-channel recorder and then delivered to Maclab and PowerMacintosh.RESULTS The active phases of IMCs occupied about 40% of total cycle in average. After microinjection oflimonene into caudate nucleus, the active phases were significantly shortened, while the cycle time of IMCswere not changed significantly. The inhibitory effects of limonene were abolished by pretreatment withatropine, whilst the atropine has no effect on IMCs.CONCLUSION It is suggested that limonene inhabits the gastrointestinal IMCs by affecting M-receptor incaudate nucleus.

  1. Dynamics in the Gravitational Field of a Cometary Nucleus

    CERN Document Server

    Jiang, Yu

    2014-01-01

    The study of dynamics near the comet is a very important topic in orbital mechanics. In this paper we are interested in analyzing the dynamical behaviors in the vicinity of a cometary nucleus. Equilibrium points and periodic orbits are discussed. There are four equilibrium points in the potential of the comet 1P/Halley nucleus, positions and eigenvalues of these equilibrium points are presented. About the periodic orbits, it is found that there are five topological classes of stably periodic orbits and six topological classes of unstably periodic orbits in the potential field of a cometary nucleus. It is found that the resonant periodic orbit can be stable, and there exist stably non-resonant periodic orbits, stably resonant periodic orbits and unstably resonant periodic orbits in the potential field of cometary nuclei. The periodic orbits with the 1:1, 1:2, and 1:8 resonances are presented.

  2. New integral formula and its applications to light nucleus reactions

    CERN Document Server

    Sun, Xiaojun

    2015-01-01

    A new integral formula, which has not been compiled in any integral tables or mathematical softwares, is proposed to obtain the analytical energy-angular spectra of the particles that are sequentially emitted from the discrete energy levels of the residual nuclei in the statistical theory of light nucleus reaction (STLN). In the cases of the neutron induced light nucleus reactions, the demonstration of the kinetic energy conservation in the sequential emission processes becomes straightforward thanks to this new integral formula and it is also helpful to largely reduce the volume of file-6 in nuclear reaction databases. Furthermore, taking p+$^9$Be reaction at 18 MeV as an example, this integral formula is extended to calculate the energy-angular spectra of the sequentially emitted neutrons for proton induced light nucleus reactions in the frame of STLN.

  3. Immobility, inheritance and plasticity of shape of the yeast nucleus

    Directory of Open Access Journals (Sweden)

    Andrulis Erik D

    2007-11-01

    Full Text Available Abstract Background Since S. cerevisiae undergoes closed mitosis, the nuclear envelope of the daughter nucleus is continuous with that of the maternal nucleus at anaphase. Nevertheless, several constitutents of the maternal nucleus are not present in the daughter nucleus. The present study aims to identify proteins which impact the shape of the yeast nucleus and to learn whether modifications of shape are passed on to the next mitotic generation. The Esc1p protein of S. cerevisiae localizes to the periphery of the nucleoplasm, can anchor chromatin, and has been implicated in targeted silencing both at telomeres and at HMR. Results Upon increased Esc1p expression, cell division continues and dramatic elaborations of the nuclear envelope extend into the cytoplasm. These "escapades" include nuclear pores and associate with the nucleolus, but exclude chromatin. Escapades are not inherited by daughter nuclei. This exclusion reflects their relative immobility, which we document in studies of prezygotes. Moreover, excess Esc1p affects the levels of multiple transcripts, not all of which originate at telomere-proximal loci. Unlike Esc1p and the colocalizing protein, Mlp1p, overexpression of selected proteins of the inner nuclear membrane is toxic. Conclusion Esc1p is the first non-membrane protein of the nuclear periphery which – like proteins of the nuclear lamina of higher eukaryotes – can modify the shape of the yeast nucleus. The elaborations of the nuclear envelope ("escapades" which appear upon induction of excess Esc1p are not inherited during mitotic growth. The lack of inheritance of such components could help sustain cell growth when parental nuclei have acquired potentially deleterious characteristics.

  4. Silk fibroin porous scaffolds for nucleus pulposus tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Chao; Yang, Qiang [Department of Spine Surgery, Tianjin Hospital, Tianjin 300211 (China); Tianjin Medical University, Tianjin 300070 (China); Zhu, Meifeng [The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Du, Lilong [Department of Spine Surgery, Tianjin Hospital, Tianjin 300211 (China); Tianjin Medical University, Tianjin 300070 (China); Zhang, Jiamin [The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Ma, Xinlong [Department of Spine Surgery, Tianjin Hospital, Tianjin 300211 (China); Xu, Baoshan, E-mail: xubaoshan99@126.com [Department of Spine Surgery, Tianjin Hospital, Tianjin 300211 (China); Wang, Lianyong, E-mail: wly@nankai.edu.cn [The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China)

    2014-04-01

    Intervertebral discs (IVDs) are structurally complex tissue that hold the vertebrae together and provide mobility to spine. The nucleus pulposus (NP) degeneration often results in degenerative IVD disease that is one of the most common causes of back and neck pain. Tissue engineered nucleus pulposus offers an alternative approach to regain the function of the degenerative IVD. The aim of this study is to determine the feasibility of porous silk fibroin (SF) scaffolds fabricated by paraffin-sphere-leaching methods with freeze-drying in the application of nucleus pulposus regeneration. The prepared scaffold possessed high porosity of 92.38 ± 5.12% and pore size of 165.00 ± 8.25 μm as well as high pore interconnectivity and appropriate mechanical properties. Rabbit NP cells were seeded and cultured on the SF scaffolds. Scanning electron microscopy, histology, biochemical assays and mechanical tests revealed that the porous scaffolds could provide an appropriate microstructure and environment to support adhesion, proliferation and infiltration of NP cells in vitro as well as the generation of extracellular matrix. The NP cell–scaffold construction could be preliminarily formed after subcutaneously implanted in a nude mice model. In conclusion, The SF porous scaffold offers a potential candidate for tissue engineered NP tissue. - Highlights: • Paraffin microsphere-leaching method is used to fabricate silk fibroin scaffold. • The scaffold has appropriate mechanical property, porosity and pore size • The scaffold supports growth and infiltration of nucleus pulposus cells. • Nucleus pulposus cells can secrete extracellular matrix in the scaffolds. • The scaffold is a potential candidate for tissue engineered nucleus pulposus.

  5. Deep brain stimulation of the subthalamic nucleus modulates sensitivity to decision outcome value in Parkinson’s disease

    Science.gov (United States)

    Seymour, Ben; Barbe, Michael; Dayan, Peter; Shiner, Tamara; Dolan, Ray; Fink, Gereon R.

    2016-01-01

    Deep brain stimulation (DBS) of the subthalamic nucleus in Parkinson’s disease is known to cause a subtle but important adverse impact on behaviour, with impulsivity its most widely reported manifestation. However, precisely which computational components of the decision process are modulated is not fully understood. Here we probe a number of distinct subprocesses, including temporal discount, outcome utility, instrumental learning rate, instrumental outcome sensitivity, reward-loss trade-offs, and perseveration. We tested 22 Parkinson’s Disease patients both on and off subthalamic nucleus deep brain stimulation (STN-DBS), while they performed an instrumental learning task involving financial rewards and losses, and an inter-temporal choice task for financial rewards. We found that instrumental learning performance was significantly worse following stimulation, due to modulation of instrumental outcome sensitivity. Specifically, patients became less sensitive to decision values for both rewards and losses, but without any change to the learning rate or reward-loss trade-offs. However, we found no evidence that DBS modulated different components of temporal impulsivity. In conclusion, our results implicate the subthalamic nucleus in a modulation of outcome value in experience-based learning and decision-making in Parkinson’s disease, suggesting a more pervasive role of the subthalamic nucleus in the control of human decision-making than previously thought. PMID:27624437

  6. Conserved Expression of the Glutamate NMDA Receptor 1 Subunit Splice Variants during the Development of the Siberian Hamster Suprachiasmatic Nucleus

    OpenAIRE

    Duffield, Giles E.; Jens D Mikkelsen; Ebling, Francis J. P.

    2012-01-01

    Glutamate neurotransmission and the N-methyl-D-aspartate receptor (NMDAR) are central to photic signaling to the master circadian pacemaker located in the hypothalamic suprachiasmatic nucleus (SCN). NMDARs also play important roles in brain development including visual input circuits. The functional NMDAR is comprised of multiple subunits, but each requiring the NR1 subunit for normal activity. The NR1 can be alternatively spliced to produce isoforms that confer different functional propertie...

  7. pH modulation of glial glutamate transporters regulates synaptic transmission in the nucleus of the solitary tract

    OpenAIRE

    Huda, Rafiq; McCrimmon, Donald R.; Martina, Marco

    2013-01-01

    The nucleus of the solitary tract (NTS) is the major site for termination of visceral sensory afferents contributing to homeostatic regulation of, for example, arterial pressure, gastric motility, and breathing. Whereas much is known about how different neuronal populations influence these functions, information about the role of glia remains scant. In this article, we propose that glia may contribute to NTS functions by modulating excitatory neurotransmission. We found that acidification (pH...

  8. The relativistic consistent angular-momentum projected shell model study of the N=Z nucleus 52Fe

    Institute of Scientific and Technical Information of China (English)

    LI YanSong; LONG GuiLu

    2009-01-01

    The relativistic consistent angular-momentum projected shell model (RECAPS) is used in the study of the structure and electromagnetic transitions of the low-lying states in the N=Z nucleus 52Fe.The model calculations show a reasonably good agreement with the data.The backbending at 12+ is reproduced and the energy level structure suggests that neutron-proton interactions play important roles.

  9. The relativistic consistent angular-momentum projected shell model study of the N=Z nucleus 52Fe

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The relativistic consistent angular-momentum projected shell model(ReCAPS) is used in the study of the structure and electromagnetic transitions of the low-lying states in the N=Z nucleus 52Fe.The model calculations show a reasonably good agreement with the data.The backbending at 12+ is reproduced and the energy level structure suggests that neutron-proton interactions play important roles.

  10. The Effects of Nucleus Accumbens μ-opioid and Adenosine 2A Receptor Stimulation and Blockade on Instrumental Learning

    OpenAIRE

    Clissold, Kara A.; Pratt, Wayne E.

    2014-01-01

    Prior research has shown that glutamate and dopamine receptors in the nucleus accumbens (NAcc) core are critical for the learning of an instrumental response for food reinforcement. It has also been demonstrated that μ-opioid and adenosine A2A receptors within the NAcc impact feeding and motivational processes. In these experiments, we examined the potential roles of NAcc μ-opioid and A2A receptors on instrumental learning and performance. Sprague-Dawley rats were food restricted and trained ...

  11. Prolactin regulation of kisspeptin neurones in the mouse brain and its role in the lactation-induced suppression of kisspeptin expression.

    Science.gov (United States)

    Brown, R S E; Herbison, A E; Grattan, D R

    2014-12-01

    Hyperprolactinaemia is a major cause of infertility in both males and females, although the mechanism by which prolactin inhibits the reproductive axis is not clear. The aim of the present study was to test the hypothesis that elevated prolactin causes suppression of kisspeptin expression in the hypothalamus, resulting in reduced release of gonadotrophin-releasing hormone (GnRH) and consequent infertility. In oestrogen-treated ovariectomised mice, chronic prolactin-treatment prevented the rise in luteinising hormone (LH) seen in vehicle-treated mice. Kiss1 mRNA was significantly suppressed in both the rostral periventricular region of the third ventricle (RP3V) and arcuate nucleus after prolactin treatment. Exogenous prolactin treatment induced phosphorylated signal transducer and activator of transcription 5 (pSTAT5) in kisspeptin neurones, and suppression of endogenous prolactin using bromocriptine reduced levels of pSTAT5 in kisspeptin neurones, suggesting that prolactin acts directly on kisspeptin neurones. By contrast, fewer than 1% of GnRH neurones expressed pSTAT5 in either dioestrous or lactating mice. As reported previously, there was significant suppression of kisspeptin mRNA and protein in the RP3V on day 7 of lactation, although not in the arcuate nucleus. Bromocriptine treatment significantly increased Kiss1 mRNA expression in the RP3V, although not to dioestrous levels. Unilateral thelectomy, aiming to eliminate sensory inputs from nipples on one side of the body, failed to alter the reduction in the number of kisspeptin neurones observed in the RP3V. These data demonstrate that chronic prolactin administration suppressed serum LH, and reduced Kiss1 mRNA levels in both the RP3V and arcuate nucleus, consistent with the hypothesis that prolactin-induced suppression of kisspeptin secretion might mediate the inhibitory effects of prolactin on GnRH secretion. During lactation, however, the suppression of Kiss1 mRNA in the RP3V was only partially reversed

  12. Role of neuronal nitric oxide synthase in the estrogenic attenuation of cannabinoid-induced changes in energy homeostasis.

    Science.gov (United States)

    Borgquist, Amanda; Meza, Cecilia; Wagner, Edward J

    2015-02-01

    Since estradiol attenuates cannabinoid-induced increases in energy intake, energy expenditure, and transmission at proopiomelanocortin (POMC) synapses in the hypothalamic arcuate nucleus (ARC), we tested the hypothesis that neuronal nitric oxide synthase (nNOS) plays an integral role. To this end, whole animal experiments were carried out in gonadectomized female guinea pigs. Estradiol benzoate (EB; 10 μg sc) decreased incremental food intake as well as O2 consumption, CO2 production, and metabolic heat production as early as 2 h postadministration. This was associated with increased phosphorylation of nNOS (pnNOS), as evidenced by an elevated ratio of pnNOS to nNOS in the ARC. Administration of the cannabinoid receptor agonist WIN 55,212-2 (3 μg icv) into the third ventricle evoked hyperphagia as early as 1 h postadministration, which was blocked by EB and restored by the nonselective NOS inhibitor N-nitro-L-arginine methyl ester hydrochloride (L-NAME; 100 μg icv) when the latter was combined with the steroid. Whole cell patch-clamp recordings showed that 17β-estradiol (E2; 100 nM) rapidly diminished cannabinoid-induced decreases in miniature excitatory postsynaptic current frequency, which was mimicked by pretreatment with the NOS substrate L-arginine (30 μM) and abrogated by L-NAME (300 μM). Furthermore, E2 antagonized endocannabinoid-mediated depolarization-induced suppression of excitation, which was nullified by the nNOS-selective inhibitor N5-[imino(propylamino)methyl]-L-ornithine hydrochloride (10 μM). These effects occurred in a sizable number of identified POMC neurons. Taken together, the estradiol-induced decrease in energy intake is mediated by a decrease in cannabinoid sensitivity within the ARC feeding circuitry through the activation of nNOS. These findings provide compelling evidence for the need to develop rational, gender-specific therapies to help treat metabolic disorders such as cachexia and obesity. PMID:25392169

  13. Recent Developments in Neutrino/Antineutrino-Nucleus Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Morfín, Jorge G.; Nieves, Juan; Sobczyk, Jan T.

    2012-01-01

    Recent experimental results and developments in the theoretical treatment of neutrino-nucleus interactions in the energy range of 1–10 GeV are discussed. Difficulties in extracting neutrino-nucleon cross sections from neutrino-nucleus scattering data are explained and significance of understanding nuclear effects for neutrino oscillation experiments is stressed. Detailed discussions of the status of two-body current contribution in the kinematic region dominated by quasielastic scattering and specific features of partonic nuclear effects in weak DIS scattering are presented.

  14. An occultation of the inner Seyfert nucleus of NGC 4151

    International Nuclear Information System (INIS)

    The brightness of the unresolved nucleus of NGC 4151 was monitored over five months in 1983. Variations of ≅ 0.1 mag/day were observed in the U-band and no significant variation was found of the -OIII] 5007 A emission line. However, an event that was observed on the nights of the 10/11 and 11/12 February 1983 in the continuum around 5672 A has all the characteristics of an occultation. It is proposed that an inner synchrotron nucleus of ≅ 3 a.u. diameter was occulted by an opaque cloud ≅ 6 a.u. across on those two nights

  15. Sensitivity of reaction cross sections to halo nucleus density distributions

    OpenAIRE

    Alkhazov, G. D.; Sarantsev, V. V.

    2013-01-01

    In order to clear up the sensitivity of the nucleus--nucleus reaction cross sections $\\sigma_R$ to the nuclear matter distributions in exotic halo nuclei, we have calculated the values of $\\sigma_R$ for scattering of $^6$He, $^{11}$Li, and $^{19}$C nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon. The calculations were performed in the "rigid target" approximation to the Glauber theory, different shapes of the nuclear density distributions in $^6$He, $^{11}$Li, and $^{19}$C ...

  16. Hyper deformation and clustering configuration in 168Yb nucleus

    International Nuclear Information System (INIS)

    Recently an exhaustive experimental search for hyper deformation in 168Yb with β ∼ 1.0 and axis ratio 3:1 at spins 70-80ℎ has yielded negative result which is attributed either to the fact that the fission of the compound nucleus prevented population of hyper deformed states or that the amount of angular momentum brought into the compound system was not sufficient to allow population of hyper deformed states. A systematic theoretical search for detection of such hyper deformation in this nucleus using the cranked Nilsson Strutinsky method with tuning to fixed spins was undertaken

  17. Examination of the fission time of the Z =120 nucleus

    Science.gov (United States)

    Sikdar, A. K.; Ray, A.; Chatterjee, A.

    2016-04-01

    We show that the large difference in the measured lifetime for asymmetric fission of the highly excited (T ≈1.5 -MeV ) Z =120 nucleus as measured by the atomic techniques (crystal blocking and x-ray methods) with those measured by the nuclear techniques (mass-angle distribution and prefission neutron multiplicity) cannot be due to the different sensitivities of the atomic and nuclear techniques in different time domains. The claim of formation of a superheavy Z =120 nucleus with a high fission barrier on the basis of an observed long fission time by the atomic techniques is in direct conflict with all other available measurements and calculations.

  18. Electromagnetic properties of the Beryllium-11 nucleus in Halo EFT

    OpenAIRE

    Hammer H.-W.; Phillips D.R.

    2010-01-01

    We compute electromagnetic properties of the Beryllium-11 nucleus using an effective field theory that exploits the separation of scales in this halo system. We fix the parameters of the EFT from measured data on levels and scattering lengths in the 10Be plus neutron system. We then obtain predictions for the B(E1) strength of the 1/2+ to 1/2− transition in the 11Be nucleus. We also compute the charge radius of the ground state of 11Be. Agreement with experiment within the expected accurac...

  19. Low-energy rotational bands in the nucleus155Eu

    Science.gov (United States)

    Katajanheimo, R.; Liljavirta, H.; Siivola, A.; Hammarén, E.; Liukkonen, E.

    1984-02-01

    Excited states in the nucleus155Eu have been produced during in-beam bombardments of a154Sm target with3He beams at 22 and 27 MeV. Decay gamma rays were detected using coincidence equipment optimized for low-energy photons. The level scheme is based on the observed γγ-coincidence relationships combined with the information on relative intensities. Tentatively suggested spin assignments follow from the apparent rotational character of the nucleus. Experimental observations are compared with predictions calculated from a particle-rotor model with a nonspheroidal Woods-Saxon potential.

  20. Recent Developments in Neutrino/Antineutrino-Nucleus Interactions

    Directory of Open Access Journals (Sweden)

    Jorge G. Morfín

    2012-01-01

    Full Text Available Recent experimental results and developments in the theoretical treatment of neutrino-nucleus interactions in the energy range of 1–10 GeV are discussed. Difficulties in extracting neutrino-nucleon cross sections from neutrino-nucleus scattering data are explained and significance of understanding nuclear effects for neutrino oscillation experiments is stressed. Detailed discussions of the status of two-body current contribution in the kinematic region dominated by quasielastic scattering and specific features of partonic nuclear effects in weak DIS scattering are presented.

  1. Rewarding and aversive effects of nicotine are segregated within the nucleus accumbens.

    Science.gov (United States)

    Sellings, Laurie H L; Baharnouri, Golriz; McQuade, Lindsey E; Clarke, Paul B S

    2008-07-01

    Forebrain dopamine plays a critical role in motivated behavior. According to the classic view, mesolimbic dopamine selectively guides behavior motivated by positive reinforcers. However, this has been challenged in favor of a wider role encompassing aversively motivated behavior. This controversy is particularly striking in the case of nicotine, with opposing claims that either the rewarding or the aversive effect of nicotine is critically dependent on mesolimbic dopamine transmission. In the present study, the effects of 6-hydroxydopamine lesions of nucleus accumbens core vs. medial shell on intravenous nicotine conditioned place preference and conditioned taste aversion were examined in male adult rats. Dopaminergic denervation in accumbens medial shell was associated with decreased nicotine conditioned place preference. Conversely, denervation in accumbens core was associated with an increase in conditioned place preference. In addition, dopaminergic denervation of accumbens core but not medial shell abolished conditioned taste aversion for nicotine. We conclude that nucleus accumbens core and medial shell dopaminergic innervation exert segregated effects on rewarding and aversive effects of nicotine. More generally, our findings indicate that dopaminergic transmission may mediate or enable opposing motivational processes within functionally distinct domains of the accumbens.

  2. Analysis of Intermediate-Energy Nucleus-Nucleus Spallation, Fission, and Fragmentation Reactions with the LAQGSM code

    CERN Document Server

    Mashnik, S G; Prael, R E; Sierk, A J

    2003-01-01

    The LAQGSM code has been recently developed at Los Alamos National Laboratory to simulate nuclear reactions for proton radiography applications. We have benchmarked our code against most available measured data both for proton-nucleus and nucleus-nucleus interactions at incident energies from 10 MeV to 800 GeV and have compared our results with predictions of other current models used by the nuclear community. Here, we present a brief description of our code and show illustrative results obtained with LAQGSM for neutron spectra measured recently by Nakamura's groups for reactions induced by light and medium nuclei on targets from C to Pb at several incident energies from 95 to 600 MeV/nucleon and with the recent GSI measurements of spallation, fission, and fragmentation yields from A+p and A+A reactions at incident energies near and below 1 GeV/nucleon. Further necessary work is outlined.

  3. Transfer of a eubacteria-type cell division site-determining factor CrMinD gene to the nucleus from the chloroplast genome in Chlamydomonas reinhardtii

    Institute of Scientific and Technical Information of China (English)

    LIU WeiZhong; HU Yong; ZHANG RunJie; ZHOU WeiWei; ZHU JiaYing; LIU XiangLin; HE YiKun

    2007-01-01

    MinD is a ubiquitous ATPase that plays a crucial role in selection of the division site in eubacteria, chloroplasts, and probably Archaea. In four green algae, Mesostigma viride, Nephroselmis olivacea, Chlorella vulgaris and Prototheca wickerhamii, MinD homologues are encoded in the plastid genome. However, in Arabidopsis, MinD is a nucleus-encoded, chloroplast-targeted protein involved in chloroplast division, which suggests that MinD has been transferred to the nucleus in higher land plants. Yet the lateral gene transfer (LGT) of MinD from plastid to nucleus during plastid evolution remains poorly understood. Here, we identified a nucleus-encoded MinD homologue from unicellular green alga Chlamydomonas reinhardtii, a basal species in the green plant lineage. Overexpression of CrMinD in wild type E. coli inhibited cell division and resulted in the filamentous cell formation, clearly demonstrated the conservation of the MinD protein during the evolution of photosynthetic eukaryotes. The transient expression of CrMinD-egfp confirmed the role of CrMinD protein in the regulation of plastid division. Searching all the published plastid genomic sequences of land plants, no MinD homologues were found, which suggests that the transfer of MinD from plastid to nucleus might have occurred before the evolution of land plants.

  4. A comparative analysis of mechanisms of fast light particles production in nucleus-nucleus collisions at low and intermediate energies

    CERN Document Server

    Denikin, A S

    2002-01-01

    The dynamics and the mechanisms of formation of pre-equilibrium light particles in nucleus-nucleus collisions at low and intermediate energies are discussed in terms of a classical four-body model. The energy and angular distributions of light particles have been calculated. It has been found that at energies lower than 50A MeV the formation of the most high-energy part of the nuclear spectrum occurs at the expense of the acceleration of light target particles with the mean field of the projectile. The obtained data are in good agreement with available experimental data

  5. Hindbrain Leptin Stimulation Induces Anorexia and Hyperthermia Mediated by Hindbrain Melanocortin Receptors

    OpenAIRE

    Skibicka, Karolina P; Grill, Harvey J.

    2008-01-01

    Of the central nervous system receptors that could mediate the energy balance effects of leptin, those of the hypothalamic arcuate nucleus receive the greatest attention. Melanocortin receptors (MC-Rs) contribute to the feeding and energetic effects of hypothalamically delivered leptin. Energy balance effects of leptin are also mediated by extrahypothalamic neurons including the hindbrain nucleus tractus solitarius. Hindbrain leptin receptors play a role in leptin's anorectic effects, but the...

  6. Physiologie intégrative du métabolisme énergétique, de l'os et de la fertilité : rôle de l'ostéocalcine et des hormones sexuelles

    OpenAIRE

    Confavreux, Cyrille

    2012-01-01

    Transgenic mice offers powerful tools to study integrative physiology especially to study a specific gene function in a whole organism. Using transgenic mice revealed the role of the skeleton on fertility and energy metabolism.Central control of bone mass. Leptin acts on brain stem and decrease serotonin neuron (SN) activity. SN project on hypothalamus to control bone mass (VMH nucleus) and appetite (arcuate nucleus). Brain serotonin reduces sympathetic tone and increases bone mass.Bone regul...

  7. Empirical Example of Nucleus with Transitional Dynamical Symmetry X(5)

    Institute of Scientific and Technical Information of China (English)

    张大立; 赵惠英

    2002-01-01

    By analysing the energy spectrum, E2 transition rates and branching ratios, it is shown explicitly that the nucleus 150Nd provides an empirical example with X(5) symmetry at the critical point of the transition from U(5) to SU(3) symmetry.

  8. Three-dimensional organization of the human interphase nucleus

    NARCIS (Netherlands)

    T.A. Knoch (Tobias); C. Münkel (Christian); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2000-01-01

    textabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown, although it is important for gene regulation and replication. For a long time the interphase nucleus has been viewed as a 'spaghetti soup' of DNA without much internal structur

  9. Three-dimensional organization of the human interphase nucleus

    NARCIS (Netherlands)

    T.A. Knoch (Tobias); M. Wachsmuth (Malte); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2002-01-01

    markdownabstractTo approach the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic properties of interphase chromosomes and cell nuclei were simulated with Monte Carlo and Brownian Dynamics methods. The 30 nm chromatin fibre was folded according to the Mu

  10. Three-dimensional organization of the human interphase nucleus.

    NARCIS (Netherlands)

    T.A. Knoch (Tobias); M. Wachsmuth (Malte); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2002-01-01

    textabstractTo approach the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic properties of interphase chromosomes and cell nuclei were simulated with Monte Carlo and Brownian Dynamics methods. The 30 nm chromatin fibre was folded according to the Multi-

  11. Three-dimensional organization of the human interphase nucleus

    NARCIS (Netherlands)

    T.A. Knoch (Tobias); M. Wachsmuth (Malte); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2002-01-01

    textabstractTo approach the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic properties of interphase chromosomes and cell nuclei were simulated with Monte Carlo and Brownian Dynamics methods. The 30 nm chromatin fibre was folded according to the Mul

  12. CTP synthase forms cytoophidia in the cytoplasm and nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Gou, Ke-Mian [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom); State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193 (China); Chang, Chia-Chun [Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Shen, Qing-Ji [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom); Sung, Li-Ying, E-mail: liyingsung@ntu.edu.tw [Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan, ROC (China); Liu, Ji-Long, E-mail: jilong.liu@dpag.ox.ac.uk [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom)

    2014-04-15

    CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase. - Highlights: • CTP synthase forms cytoophidia not only in the cytoplasm but also in the nucleus. • Glutamine deprivation and Glutamine analogs promotes cytoophidium formation. • N-cytoophidia exhibit distinct morphology when compared to C-cytoophidia. • Both CTP synthase 1 and CTP synthase 2 form cytoophidia in mammalian cells. • Fusions of cytoophidia occur in the cytoplasm and nucleus.

  13. Theory status of quarkonium production in proton-nucleus collisions

    CERN Document Server

    Lansberg, J P

    2015-01-01

    I give a brief overview of the recent theoretical progress in the study of quarkonium production in proton-nucleus collisions in view of the recent LHC and RHIC results. A special emphasis is put on the excited states such as the psi', Upsilon(2S) and Upsilon(3S).

  14. Parity non-conserving effects in neutron-nucleus scattering

    International Nuclear Information System (INIS)

    The present lecture reviews the motivations which led to study the contribution of the neutron-nucleus component to parity-non-conserving effects observed in medium-heavy nuclei and considers its present status. It is shown that it cannot account for those experimental data. The order interpretation of these effects, which cannot lead to precise statements, is schematically described

  15. Saturating Cronin effect in ultrarelativistic proton-nucleus collisions

    CERN Document Server

    Papp, G; Fái, G; Papp, Gabor; Levai, Peter; Fai, George

    2000-01-01

    Pion and photon production cross sections are analyzed in proton-proton and proton-nucleus collisions at energies 20 GeV < s^1/2 < 60 GeV. We separate the proton-proton and nuclear contributions to transverse-momentum broadening and suggest a new mechanism for the nuclear enhancement in the high transverse-momentum region.

  16. RELATIVISTIC CALCULATIONS OF THE SUPERHEAVY NUCLEUS 114-298

    NARCIS (Netherlands)

    BOERSMA, HF

    1993-01-01

    We investigate ground-state properties of the superheavy nucleus with N = 184 and Z = 114, (298)114, using conventional relativistic mean-field theory and density-dependent mean-field theory, which reproduces Dirac-Brueckner calculations in nuclear matter. Our calculations provide support for N = 18

  17. Deexcitation of superdeformed bands in the nucleus Tb-151

    NARCIS (Netherlands)

    Finck, C; Appelbe, D; Beck, FA; Byrski, T; Cullen, D; Curien, D; deFrance, G; Duchene, G; Erturk, S; Haas, B; Khadiri, N; Kharraja, B; Prevost, D; Rigollet, C; Stezowski, O; Twin, P; Vivien, JP; Zuber, K

    1997-01-01

    The aim of this work is to get more informations about the decay-out of superdeformed bands. One of the best candidates in the mass A similar or equal to 150 region for that kind of research is the nucleus Tb-151. From previous works, it has been established that the first excited band goes lower in

  18. Rapid feedback processing in human nucleus accumbens and motor thalamus

    NARCIS (Netherlands)

    Schüller, T.; Gründler, T.O.J.; Jocham, G.; Klein, T.A.; Timmermann, L.; Visser-Vandewalle, V.E.R.M.; Kuhn, J.

    2015-01-01

    The nucleus accumbens (NAcc) and thalamus are integral parts in models of feedback processing. Deep brain stimulation (DBS) has been successfully employed to alleviate symptoms of psychiatric conditions including obsessive-compulsive disorder (OCD) and Tourette's syndrome (TS). Common target structu

  19. Physical interrelation of volatile and refractories in a cometary nucleus

    Science.gov (United States)

    Fulle, Marco; Alice Team (PI Alan Stern), CONSTERT Team (PI Wlodek Kofman), COSIMA Team (PI Martin Hilchenbach), GIADA Team (PI Alessandra Rotundi), MIDAS Team (PI Mark Bentley), MIRO Team (PI Mark Hofstadter), OSIRIS Team (PI Holger Sierks), ROSINA Team (PI Kathrin Altwegg), RPC Team (PIs Hans Nilsson, James Burch, Anders Eriksson, Karl Heinz-Glassmeier, Pierre Henri, Christopher Carr), RSI Team (PI Martin Paetzold), VIRTIS Team (PI Fabrizio Capaccioni), Lander Team (Lead Scientists: Hermann Boehnhardt and Jean-Pierre Bibring), IDS Team (Eberhard Gruen, Marcello Fulchignoni, Paul Weissman), Project Scientist Team (Matt Taylor, Bonnie Buratti, Nicolas Altobelli, Mathieu Choukroun), Ground-Based Observations Team (Colin Snodgrass)

    2016-10-01

    The Rosetta mission has been taking measurements of its target comet Comet 67P/Churyumov-Gerasimenko since early 2014 and will complete operations at the end of September 2016. The mission Science Management Plan, in 1994, laid out the the prime goals and themes of the mission. These five themes were: 1) To study the global characterisation of the Nuclues, the determination of the dynamics properties , surface morpholy and composition of the comet. 2) Examination of the Chemical, Mineralogical and isotopic compositions of volatiles and refractories in a cometary nucleus.3) Physical interrelation of volatile and refractories in a cometary nucleus4) Study the development of cometary activity and the process in the surface layer of the nucleus and in the inner coma5) The origins of comets, the relationship between cometary and interstellar material and the implications for the origin of the solar system,To cover all aspects of the Rosetta mission in this special Show case session, this abstracts is one of 5, with this particular presentation focusing on theme 3, in particular on a) The dust-to-gas ratio; b) distributed sources of volatiles; c) seasonal evolution of the dust size distribution.a) The dust-to-gas ratio has been provided by coma observations measuring the gas and dust loss rates from the nucleus surface. The ratio of these two loss rates provides a lower limit of the dust-to-gas ratio at the nucleus surface, since it does not take into account the largest chunks unable to leave the nucleus, or falling back due to the dominant gravity. We review the value inferred so far, its time evolution, and new techniques to directly measure it in the nucleus.b) Evidences offered by Rosetta observations of gas sublimating from dust particles are up to now faint. We report the few available observations and an estimate of the probable average water content in dust particles inferred by 3D gas-dynamical codes of 67P coma.c) The dust-size distribution tunes the sizes

  20. Brackett Gamma Imaging of the Nucleus of M83

    Science.gov (United States)

    Crosthwaite, L. P.; Turner, J. L.; Beck, S. C.; Meier, D. S.

    2004-12-01

    The gas-rich nucleus of barred spiral galaxy, M83, is a hotbed of star formation, with a total infrared luminosity of 4 X 109 Lo. We have observed the nucleus of M83 with the near infrared spectrometer, NIRSPEC, on Keck 2 to obtain high resolution Brγ recombination line spectra of the nucleus. Simultaneous imaging with the SCAM camera in a broadband K filter shows the position of the slit on the near-infrared galaxy. This allows us to map the nucleus with a continuum reference. The SCAM image shows a bright peak at the nucleus and a complex semi-circular arc of emission to the southwest. We stepped the 0.5'' X 24'' length slit in small declination increments to map a 20'' X 20'' region just west of the nucleus. Individual spectra were used to form a ra-dec-lambda cube and an integrated intensity map of Brγ . A total of 1.1 X 10-16 W m-2 of Brγ emission is detected in the map, in good agreement with previous low resolution observations (Turner, Ho, & Beck 1987, ApJ, 313, 644). This is not corrected for extinction within the molecular clouds in M83 or to the nebulae themselves and is therefore a lower limit to the true Brγ flux. Extinction is estimated to be at least a magnitude in the near-IR as measured in larger (4'') beams (Turner et al.) The bulk of the Brγ emission extends along the northern portion of the near-IR continuum semi-circle. Twenty percent of the total Brγ emission comes from single a 3'' (FWHM) source located 5'' west of the near-IR nucleus. The complementary NIRSPEC Brα data we have obtained will eventually allow us to evaluate the near-IR extinction on subarcsecond sizescales and obtain an extinction-corrected estimate of the Lyman continuum rate and therefore the number of ionizing stars.